The British Columbia Building Code | Note to Part 9 | Housing and Small Buildings Pt 1

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Notes to Part 9

Housing and Small Buildings

A-9.1.1.1.(1) Application of Part 9 to Seasonally and Intermittently Occupied Buildings. The British Columbia

Building Code does not provide separate requirements which would apply to seasonally or intermittently occupied buildings. Without

compromising the basic health and safety provisions, however, various requirements in Part 9 recognize that leniency may be

appropriate in some circumstances. With greater use of “cottages” through the winter months, the proliferation of seasonally occupied

multiple-dwelling buildings and the increasing installation of modern conveniences in these buildings, the number and extent of

possible exceptions is reduced.

Energy Efficiency

Clause 9.36.1.3.(5)(b) exempts seasonally occupied residential buildings such as summer cottages from the requirements of

Section 9.36. Cottages intended for continuous or regular winter use such as ski cabins are required to conform to Section 9.36.

Thermal Insulation

Article 9.25.2.1. specifies that insulation is to be installed in walls, ceilings and floors which separate heated space from unheated

space. Cottages intended for use only in the summer and which, therefore, have no space heating appliances, would not be

required to be insulated. Should a heating system be installed at some later date, insulation should also be installed at that time in

accordance with Article 9.25.1.1. and the insulation tables in Section 9.36. However, if the building were not intended for

continuous or regular winter use, it may still be exempted from the remainder of the energy efficiency requirements in

Section 9.36.

Air Barrier Systems and Vapour Barriers

Articles 9.25.3.1. and 9.25.4.1. require the installation of air barrier systems and vapour barriers only where insulation is installed.

Dwellings with no heating system would thus be exempt from these requirements. In some cases, seasonally occupied buildings

that are conditioned may be required to conform to the air and vapour barrier requirements of Section 9.25, but not to the air

barrier and other requirements of Section 9.36.

Interior Wall and Ceiling Finishes

The choice of interior wall and ceiling finishes has implications for fire safety. Where a dwelling is a detached building, there are

no fire resistance requirements for the walls or ceilings within the dwelling. The exposed surfaces of walls and ceilings are required

to have a flame-spread rating not greater than 150 (Subsection 9.10.17.). There is, therefore, considerable flexibility, even in

continuously occupied dwellings, with respect to the materials used to finish these walls. Except where waterproof finishes are

required (Subsection 9.29.2.), ceilings and walls may be left unfinished. Where two units adjoin, however, additional fire

resistance requirements may apply to interior loadbearing walls, floors and the shared wall (Article 9.10.8.3., and

Subsections 9.10.9. and 9.10.11.).

Plumbing and Electrical Facilities

Plumbing fixtures are required only where a piped water supply is available (Subsection 9.31.4.), and electrical facilities only

where electrical services are available (Article 9.34.1.2.).

A-9.3.1.7. Ratio of Water to Cementing Material. While adding water to concrete on site may facilitate its distribution

through formwork, this practice can have several undesirable results, such as reduced strength, greater porosity, and more propensity to

shrinkage cracking. The ratio of water to cementing material is determined according to weight. For example, using Table 9.3.1.7.,

the maximum water-cement ratio of 0.45 for a 20 mm coarse aggregate would require 18 kg (or 18 L) of water (1 L of water

weighs 1 kg).

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.3.2.1.(1) Grade Marking of Lumber. Lumber is generally grouped for marketing into the species combinations

contained in Table A-9.3.2.1.(1)-A. The maximum allowable spans for those combinations are listed in the span tables for joists,

rafters and beams. Some species of lumber are also marketed individually. Since the allowable span for the northern species

combination is based on the weakest species in the combination, the use of the span for this combination is permitted for any

individual species not included in the Spruce-Pine-Fir, Douglas Fir-Larch and Hemlock-Fir combinations.

Facsimiles of typical grade marks of lumber associations and grading agencies accredited by the Canadian Lumber Standards (CLS)

Accreditation Board to grade mark lumber in Canada are shown in Table A-9.3.2.1.(1)-B. Accreditation by the CLS Accreditation

Board applies to the inspection, grading and grade marking of lumber, including mill supervisory service, in accordance with

CSA O141, “Softwood Lumber.”

The grade mark of a CLS accredited agency on a piece of lumber indicates its assigned grade, species or species combination, moisture

condition at the time of surfacing, the responsible grader or mill of origin and the CLS accredited agency under whose supervision the

grading and marking was done.

Canadian lumber is graded to the “Standard Grading Rules for Canadian Lumber,” published by the National Lumber Grades

Authority. These rules specify standard grade names and grade name abbreviations for use in grade marks to provide positive

identification of lumber grades. In a similar fashion, standard species names or standard species abbreviations, symbols or marks are

provided in the rules for use in grade marks.

Grade marks denote the moisture content of lumber at the time of surfacing. “S-Dry” in the mark indicates the lumber was surfaced at

a moisture content not exceeding 19%. “MC 15” indicates a moisture content not exceeding 15%. “S-GRN” in the grade mark

signifies that the lumber was surfaced at a moisture content higher than 19% at a size to allow for natural shrinkage during seasoning.

Each mill or grader is assigned a permanent number. The point of origin of lumber is identified in the grade mark by use of a mill or

grader number or by the mill name or abbreviation. The CLS certified agency under whose supervision the lumber was grade marked

is identified in the mark by the registered symbol of the agency.

Table A-9.3.2.1.(1)-A

Species Designations and Abbreviations

Forming Part of Note A-9.3.2.1.(1)

Commercial Designation of Species or Species

Combination

Abbreviation Permitted on Grade

Stamps

Species Included

Douglas Fir – Larch D Fir – L (N) Douglas Fir, Western Larch

Hemlock – Fir Hem – Fir (N) Western Hemlock, Amabilis Fir

Spruce – Pine – Fir

S – P – F or

Spruce – Pine – Fir

White Spruce, Engelmann Spruce, Black Spruce, Red

Spruce, Lodgepole Pine, Jack Pine, Alpine Fir, Balsam Fir

Northern Species North Species

Any Canadian softwood covered by the

“Standard Grading Rules for Canadian Lumber”

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Table A-9.3.2.1.(1)-B

Facsimiles of Grade Marks Used by Canadian Lumber Manufacturing Associations and Agencies

Authorized to Grade Mark Lumber in Canada

Forming Part of Note A-9.3.2.1.(1)

Facsimiles of Grade Mark Association or Agency

Alberta Forest Products Association

www.albertaforestproducts.ca

Canadian Mill Services Association

www.canserve.org

Canadian Softwood Inspection Agency Inc.

www.canadiansoftwood.com

Central Forest Products Association Inc.

c/o Alberta Forest Products Association

www.albertaforestproducts.ca

GG00056B

A.F .P .A.

–

NLG

GG00062B

CMSA

KD-HT

NLGA

GG00098A

D-HTD - H T

D FIRFIR-

(

)

GAGA

CSI

GG00058B

NLGA

-HTHT

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Council of Forest Industries

www.cofi.org

Macdonald Inspection Services Ltd.

www.gradestamp.com

Maritime Lumber Bureau

www.mlb.ca

Newfoundland & Labrador Lumber Producers’ Association

www3.nf.sympatico.ca/nllpa

Table A-9.3.2.1.(1)-B (continued)

Facsimiles of Grade Marks Used by Canadian Lumber Manufacturing Associations and Agencies

Authorized to Grade Mark Lumber in Canada

Forming Part of Note A-9.3.2.1.(1)

Facsimiles of Grade Mark Association or Agency

GG00057B

S-P-F

NLGA

NLGANLGA

KD-HT

D FIRD FIR - - L(N)L(N)

GG00064B

No. 2

S - P - F

NLGA

S-P-F

No.1

KD-HT

NLGA

GG00065B

GG00066B

NLGAN L G A

NO.NO.

000

KD HTKD HT

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-Table 9.3.2.1. Lumber Grading. To identify board grades, the paragraph number of the NLGA “Standard Grading Rules

for Canadian Lumber” under which the lumber is graded must be shown in the grade mark. Paragraph 113 is equivalent to the

WWPA “Western Lumber Grading Rules” and paragraph 114 is equivalent to the WCLIB “Standard Grading Rules.” When graded

in accordance with WWPA or WCLIB rules, the grade mark will not contain a paragraph number.

Northwest Territories Forest Industries Association

Ontario Forest Industries Association

www.ofia.com

Ontario Lumber Manufacturers’ Association

(Home of CLA Grading and Inspection)

www.olma.ca

Pacific Lumber Inspection Bureau

www.plib.org

Quebec Forest Industry Council

(Conseil de l’industrie forestière du Québec)

www.qfic.gc.ca

Table A-9.3.2.1.(1)-B (continued)

Facsimiles of Grade Marks Used by Canadian Lumber Manufacturing Associations and Agencies

Authorized to Grade Mark Lumber in Canada

Forming Part of Note A-9.3.2.1.(1)

Facsimiles of Grade Mark Association or Agency

GG00067B

10 10

NLGA

GRN

CONST S

GG00059B

CLA

100

S-P-F

NLGA

KD-HT

GG00068B

O.L.M.A. 09

1 1

NLGA

GG00069B

NO. 1

0 0

NLGA RULES

GG00070B

477477

S-P-FS-P-F

KD-HTKD-HT

NLGANLGA

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.3.2.8.(1) Non-Standard Lumber. NLGA 2014, “Standard Grading Rules for Canadian Lumber,” permits lumber to

be dressed to sizes below the standard sizes (38 × 89, 38 × 140, 38 × 184, etc.) provided the grade stamp shows the reduced size.

This Sentence permits the use of the span tables for such lumber, provided the size indicated on the stamp is not less than 95% of

the corresponding standard size. Allowable spans in the tables must be reduced a full 5% even if the undersize is less than the

5% permitted.

A-9.3.2.9.(1) Protection from Termites.

Figure A-9.3.2.9.(1)-A

Known termite locations

Note to Figure A-9.3.2.9.(1)-A:

(1) Reference: J.K. Mauldin (1982), N.Y. Su (1995), T. Myles (1997).

Manitoba

Northwest

Territories

Nunavut

Yuko n

P.E.I.

EG02049A

British

Columbia

Quebec

Hudson

Bay

New

Brunswick

Nova

Scotia

Newfoundland

Areas in which specific

locations with termites

have been identified.

Alberta

Saskatchewan

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Figure A-9.3.2.9.(1)-B

Clearances under structural wood elements and visibility of supporting elements where required to permit inspection for

termite infestation

Note to Figure A-9.3.2.9.(1)-B:

(1) For the height of structural wood elements not directly above finished ground, see Article 9.23.2.3.

A-9.3.2.9.(3) Protection of Structural Wood Elements from Moisture and Decay. There are many above-ground,

structural wood systems where precipitation is readily trapped or drying is slow, creating conditions conducive to decay. Beams

extending beyond roof decks, junctions between deck members, and connections between balcony guards and walls are three examples

of elements that can accumulate water when exposed to precipitation if they are not detailed to allow drainage.

A-9.3.2.9.(4) Protection of Retaining Walls and Cribbing from Decay. Retaining walls supporting soil are considered

to be structural elements of the building if a line drawn from the outer edge of the footing to the bottom of the exposed face of the

retaining wall is greater than 45° to the horizontal. Retaining walls supporting soil may be structural elements of the building if the line

described above has a lower slope.

Figure A-9.3.2.9.(4)

Identifying retaining walls that require preservative treatment

Retaining walls that are not critical to the support of building foundations but are greater than 1.2 m in height may pose a danger of

sudden collapse to persons adjacent to the wall if the wood is not adequately protected from decay. The height of the retaining wall or

cribbing is measured as the vertical difference between the ground levels on each side of the wall.

A-9.4.1.1. Structural Design. Article 9.4.1.1. establishes the principle that the structural members of Part 9 buildings must

• comply with the prescriptive requirements provided in Part 9,

• be designed in accordance with accepted good practice, or

• be designed in accordance with Part 4 using the loads and limits on deflection and vibration specified in Part 9 or Part 4.

Usually a combination of approaches is used. For example, even if the snow load calculation on a wood roof truss is based on

Subsection 9.4.2., the joints must be designed in accordance with Part 4. Wall framing may comply with the prescriptive requirements

in Subsections 9.23.3., 9.23.10., 9.23.11. and 9.23.12., while the floor framing may be engineered.

EG02050B

supporting elements visible

to permit inspection

(1)

clear height of 450 mm between

structural wood elements and

finished ground directly below

≥ 450 mm

wall

height

< 45˚: retaining wall may be

supporting the building

> 45˚: retaining wall is

supporting the building

EG02051A

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Design according to Part 4 or accepted good engineering practice, such as that described in CWC 2014, “Engineering Guide for

Wood Frame Construction,” requires engineering expertise. The CWC Guide contains alternative solutions and provides information

on the applicability of the Part 9 prescriptive structural requirements to further assist designers and building officials to identify the

appropriate design approach. The need for professional involvement in the structural design of a building, whether to Part 4 or Part 9

requirements or accepted good practice, is defined by provincial and territorial legislation.

A-9.4.2.1.(1) Soft Conversion from Imperial Units. The conversion table at the end of the Code provides factors for the

conversion of millimeters to inches. However, not all metric measurements stated in the Code are exact conversions. For example,

while the dimensions given for wood framing members are the exact dimensions of the milled product – i.e., what is commonly

referred to as a “2 × 4” is actually 1.5 in. × 3.5 in., which, in mm, is 38 × 89 – the metric dimensions given for spacing between

framing elements are actually soft conversions:

It remains common construction practice to arrange joists, rafters and studs in 12, 16 or 24 in. increments so as to properly align them

with the edges of sheathing materials. It is therefore assumed that structural elements will be spaced according to the actual

metric equivalents.

A-9.4.2.2. Application of Simplified Part 9 Snow Loads. The simplified specified snow loads described in

Article 9.4.2.2. may be used where the structure is of the configuration that is typical of traditional wood-frame residential

construction and its performance. This places limits on the spacing of joists, rafters and trusses, the spans of these members and

supporting members, deflection under load, overall dimensions of the roof and the configuration of the roof. It assumes considerable

redundancy in the structure.

Because very large buildings may be constructed under Part 9 by constructing firewalls to break up the building area, it is possible to

have Part 9 buildings with very large roofs. The simplified specified snow loads may not be used when the total roof area of the overall

structure exceeds 4550 m

. Thus, the simplified specified snow load calculation may be used for typical townhouse construction but

would not be appropriate for much larger commercial or industrial buildings, for example.

The simplified specified snow loads are also not designed to take into account roof configurations that seriously exacerbate snow

accumulation. This does not pertain to typical projections above a sloped roof, such as dormers, nor does it pertain to buildings with

higher and lower roofs. Although two-level roofs generally lead to drift loading, smaller light-frame buildings constructed according to

Part 9 have not failed under these loads. Consequently, the simplified calculation may be used in these cases. Rather, this limitation on

application of the simplified calculation pertains to roofs with high parapets or significant other projections above the roof, such as

elevator penthouses, mechanical rooms or larger equipment that would effectively collect snow and preclude its blowing off the roof.

The reference to Article 9.4.3.1. invokes, for roof assemblies other than common lumber trusses, the same performance criteria

for deflection.

The specific weight of snow on roofs, , obtained from measurements at a number of weather stations across Canada varied from about

1.0 to 4.5 kN/m

. An average value for use in design in lieu of better local data is  =3.0 kN/m

. In some locations the specific weight

of snow may be considerably greater than 3.0 kN/m

. Such locations include regions where the maximum snow load on the roof is

reached only after contributions from many snowstorms, coastal regions, and regions where winter rains are considerable and where a

unit weight as high as 4.0 kN/m

may be appropriate.

A-9.4.2.3.(1) Accessible Platforms Subject to Snow and Occupancy Loads. Many platforms are subject to both

occupancy loads and snow loads. These include balconies, decks, verandas, flat roofs over garages and carports. Where such a platform,

or a segregated area of such a platform, serves a single dwelling unit, it must be designed for the greater of either the specified snow

load or an occupancy load of 1.9 kPa. Where the platform serves more than one single dwelling unit or an occupancy other than a

residential occupancy, higher occupancy loads will apply as specified in Table 4.1.5.3.

Table A-9.4.2.1.(1)

Imperial Unit Exact Metric Conversion Soft Metric Conversion Used in Code

12 in. 305 mm 300 mm

16 in. 406 mm 400 mm

24 in. 610 mm 600 mm

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.4.2.4.(1) Specified Loads for Attics or Roof Spaces with Limited Accessibility. Typical residential roofs are

framed with roof trusses and the ceiling is insulated.

Residential trusses are placed at 600 mm on centre with web members joining top and bottom chords. Lateral web bracing is installed

perpendicular to the span of the trusses. As a result, there is limited room for movement inside the attic or roof space or for storage of

material. Access hatches are generally built to the minimum acceptable dimensions, further limiting the size of material that can be

moved into the attic or roof space.

With exposed insulation in the attic or roof space, access is not recommended unless protective clothing and breathing apparatus

are worn.

Thus the attic or roof space is recognized as uninhabitable and loading can be based on actual dead load. In emergency situations or for

the purpose of inspection, it is possible for a person to access the attic or roof space without over-stressing the truss or causing

damaging deflections.

A-Table 9.4.4.1. Classification of Soils. Sand or gravel may be classified by means of a picket test in which a 38 mm by

38 mm picket beveled at the end at 45° to a point is pushed into the soil. Such material is classified as “dense or compact” if a man of

average weight cannot push the picket more than 200 mm into the soil and “loose” if the picket penetrates 200 mm or more.

Clay and silt may be classified as “stiff” if it is difficult to indent by thumb pressure, “firm” if it can be indented by moderate thumb

pressure, “soft” if it can be easily penetrated by thumb pressure, where this test is carried out on undisturbed soil in the wall of a

test pit.

A-9.4.4.4.(1) Soil Movement. In susceptible soils, changes in temperature or moisture content can cause significant expansion

and contraction. Soils containing pyrites can expand simply on exposure to air.

Expansion and Contraction due to Moisture

Clay soils are most prone to expansion and contraction due to moisture. Particularly wet seasons can sufficiently increase the

volume of the soil under and around the structure to cause heaving of foundations and floors-on-ground, or cracking of

foundation walls. Particularly dry seasons or draw-down of water by fast-growing trees can decrease the volume of the soil

supporting foundations and floors-on-ground, thus causing settling.

Frost Heave

Frost heave is probably the most commonly recognized phenomenon related to freezing soil. Frost heave results when moisture

in frost-susceptible soil (clay and silt) under the footings freezes and expands. This mechanism is addressed by requirements in

Section 9.12. regarding the depth of excavations.

Ice Lenses

When moisture in frost-susceptible soils freezes, it forms an ice lens and reduces the vapour pressure in the soil in the area

immediately around the lens. Moisture in the ground redistributes to rebalance the vapour pressures providing more moisture in

the area of the ice lens. This moisture freezes to the lens and the cycle repeats itself. As the ice lens grows, it exerts pressure in the

direction of heat flow. When lenses form close to foundations and heat flow is toward the foundation – as may be the case with

unheated crawl spaces or open concrete block foundations insulated on the interior – the forces may be sufficient to crack

the foundation.

Adfreezing

Ice lenses can adhere themselves to cold foundations. Where heat flow is essentially upward, parallel to the foundation, the

pressures exerted will tend to lift the foundation. This may cause differential movement or cracking of the foundation. Heat loss

through basement foundations of cast-in-place concrete or concrete block insulated on the exterior appears to be sufficient to

prevent adfreezing. Care must be taken where the foundation does not enclose heated space or where open block foundations are

insulated on the interior. The installation of semi-rigid glass fibre insulation has demonstrated some effectiveness as a separ

ation

layer to absorb

the adfreezing forces.

Pyrites

Pyrite is the most common iron disulphide mineral in rock and has been identified in rock of all types and ages. It is most

commonly found in metamorphic and sedimentary rock, and especially in coal and shale deposits.

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Weathering of pyritic shale is a chemical-microbiological oxidation process that results in volume increases that can heave

foundations and floors-on-ground. Concentrations of as little as 0.1% by weight have caused heaving. Weathering can be

initiated simply by exposing the pyritic material to air. Thus, building on soils that contain pyrites in concentrations that will

cause damage to the building should be avoided, or measures should be taken to remove the material or seal it. Material

containing pyrites should not be used for backfill at foundations or for supporting foundations or floors-on-ground.

Where it is not known if the soil or backfill contains pyritic material in a deleterious concentration, a test is available to identify its

presence and concentration.

References:

(1) Legget, R.F. and Crawford, C.B. Trees and Buildings. Canadian Building Digest 62, Division of Building Research, National

Research Council Canada, Ottawa, 1965.

(2) Hamilton, J.J. Swelling and Shrinking Subsoils. Canadian Building Digest 84, Division of Building Research, National

Research Council Canada, Ottawa, 1966.

(3) Hamilton, J.J. Foundations on Swelling and Shrinking Subsoils. Canadian Building Digest 184, Division of Building

Research, National Research Council Canada, Ottawa, 1977.

(4) Penner, W., Eden, W.J., and Gratten-Bellew, P.E. Expansion of Pyritic Shales. Canadian Building Digest 52, Division of

Building Research, National Research Council Canada, Ottawa, 1975.

(5) Swinton, M.C., Brown, W.C., and Chown, G.A. Controlling the Transfer of Heat, Air and Moisture through the Building

Envelope. Small Buildings – Technology in Transition, Building Science Insight ’90, Institute for Research in Construction,

National Research Council Canada, Ottawa, 1990.

A-9.4.4.6. and 9.15.1.1. Loads on Foundations. The prescriptive solutions provided in Part 9 relating to footings and

foundation walls only account for the loads imposed by drained earth. Drained earth is assumed to exert a load equivalent to the load

that would be exerted by a fluid with a density of 480 kg/m

. The prescriptive solutions do not account for surcharges from saturated

soil or additional loads from heavy objects located adjacent to the building. Where such surcharges are expected, the footings and

foundation walls must be designed and constructed according to Part 4.

A-9.5.1.2. Combination Rooms. If a room draws natural light and natural ventilation from another area, the opening

between the two areas must be large enough to effectively provide sufficient light and air. This is why a minimum opening of 3 m

required, or the equivalent of a set of double doors. The effectiveness of the transfer of light and air also depends on the size of the

transfer opening in relation to the size of the dependent room; in measuring the area of the wall separating the two areas, the whole

wall on the side of the dependent room should be considered, not taking into account offsets that may be in the surface of the wall.

The opening does not necessarily have to be in the form of a doorway; it may be an opening at eye level. However, if the dependent

area is a bedroom, provision must be made for the escape window required by Article 9.9.10.1. to fulfill its safety function. This is why

a direct passage is required between the bedroom and the other area; the equivalent of at least a doorway is therefore required for direct

passage between the two areas.

A-9.5.5.3. Doorways to Rooms with a Bathtub, Shower or Water Closet. If the minimum 860 mm hallway serves

more than one room with identical facilities, only one of the rooms is required to have a door not less than 760 mm wide.

If a number of rooms have different facilities, for example, one room has a shower, lavatory and water closet, and another room has a

lavatory and water closet, the room with the shower, lavatory and water closet must have the minimum 760 mm wide door.

Where multiple rooms provide the same or similar facilities, one of these rooms must comply with the requirement to have at least one

bathtub or shower, one lavatory and one water closet. Where the fixtures are located in two separate rooms served by the same hallway,

the requirement for the minimum doorway width would apply to both rooms.

If the minimum 860 mm hallway does not serve any room containing a bathtub, shower and water closet, additional fixtures do not

need to be installed.

A-9.6.1.1.(1) Application. The scope of this Section includes glass installed on the interior or on the exterior of a building.

A-9.6.1.2.(2) Mirrored Glass Doors. CAN/CGSB-82.6-M, “Doors, Mirrored Glass, Sliding or Folding, Wardrobe,” covers

mirrored glass doors for use on reach-in closets. It specifies that such doors are not to be used for walk-in closets.

A-Table 9.6.1.3. Glass in Doors. Maximum areas in Table 9.6.1.3.-G for other than fully tempered glazing are cut off at

1.50 m

, as this would be the practical limit after which safety glass would be required by Sentence 9.6.1.4.(2).

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.7. Windows, Doors and Skylights. This section applies only to windows, doors and skylights as defined in the scope of

the standards referenced in Article 9.7.4.2. Other glazed products, such as site-built windows, curtain walls or sloped glazing, are

required to conform to Part 5.

It is also permitted for fenestration products within the scope of the NAFS standard to conform to Part 5. This option is typically used

for windows and doors that are impractical to subject to the testing requirements of NAFS due to their size or for custom

configurations.

A-9.7.3.2.(1)(a) Minimizing Condensation. The total prevention of condensation on the surfaces of fenestration products is

difficult to achieve and, depending on the design and construction of the window or door, may not be absolutely necessary.

Clause 9.7.3.2.(1)(a) therefore requires that condensation be minimized, which means that the amount of moisture that condenses on

the inside surface of a window, door or skylight, and the frequency at which this occurs, must be limited. The occurrence of such

condensation must be sufficiently rare, the accumulation of any water must be sufficiently small, and drying must be sufficiently rapid

to prevent the deterioration of moisture-susceptible materials and the growth of fungi.

A-9.7.4. Design and Construction. Garage doors, sloped glazing, curtain walls, storefronts, commercial entrance systems,

site-built or site-glazed products, revolving doors, interior windows and doors, storm windows, storm doors, sunrooms and

commercial steel doors are not in the scope of NAFS.

All windows, doors and skylights installed to separate conditioned space from unconditioned space or the exterior must also conform

to Section 9.36.

A-9.7.4.2.(1) Standards Referenced for Windows, Doors and Skylights.

General

Doors between an unconditioned garage and a dwelling unit are considered to be in scope of the standard referenced in this

Sentence. Although the standard refers to windows in “exterior building envelopes”, a note to the definition of “building

envelope” clarifies that for the purpose of application of the standard, in some cases a building envelope may consist of 2 separate

walls (such as a wall between garage and dwelling unit as well as the exterior wall of the garage itself).

A door leading to the exterior from an unconditioned garage is also within scope of the referenced standard, as it is also part of the

exterior building envelope. However, because the scope of the BC Building Code takes precedence, these doors are not required to

conform to “NAFS”. This Subsection of the Code does not apply to a door separating two unconditioned spaces.

Canadian Requirements in the Harmonized Standard

In addition to referencing the Canadian Supplement, CSA A440S1, “Canadian Supplement to AAMA/WDMA/CSA

101/I.S.2/A440, NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights,” the

Harmonized Standard, AAMA/WDMA/CSA 101/I.S.2/A440, “NAFS – North American Fenestration Standard/Specification

for Windows, Doors, and Skylights,” contains some Canada-specific test criteria.

Standards Referenced for Excluded Products

Clause 1.1, General, of the Harmonized Standard defines the limits to the application of the standard with respect to various

types of fenestration products. A list of exceptions to the application statement identifies a number of standards that apply to

excluded products. Compliance with those standards is not required by the Code; the references are provided for information

purposes only.

Label Indicating Performance and Compliance with Standard

The Canadian Supplement requires that a product’s performance ratings be indicated on a label according to the designation

requirements in the Harmonized Standard and that the label include

• design pressure, where applicable,

•

negative design pressure, where applicable,

• water penetration test pressure, and

• the Canadian air infiltration and exfiltration levels.

It should be noted that, for a product to carry a label in Canada, it must meet all of the applicable requirements of both the

Harmonized Standard and the Canadian Supplement, including the forced entry requirements.

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Water Penetration Resistance

For the various performance grades listed in the Harmonized Standard, the corresponding water penetration resistance test

pressures are a percentage of the design pressure. For R-class products, water penetration resistance test pressures are 15% of

design pressure. In Canada, driving rain wind pressures (DRWP) have been determined for the locations listed in Appendix C.

These are listed in the Canadian Supplement. The DRWP given in the Canadian Supplement must be used for all products

covered in the scope of the Harmonized Standard when used in buildings within the scope of Part 9.

To achieve equivalent levels of water penetration resistance for all locations, the Canadian Supplement includes a provision for

calculating specified DRWP at the building site considering building exposure. Specified DRWP values are, in some cases, greater

than 15% of design pressure and, in other cases, less than 15% of design pressure. For a fenestration product to comply with the

Code, it must be able to resist the structural and water penetration loads at the building site. Reliance on a percentage of design

pressure for water penetration resistance in the selection of an acceptable fenestration product will not always be adequate.

Design pressure values are reported on a secondary designator, which is required by the Canadian Supplement to be affixed to the

window.

As an alternative to the above noted provision in the Canadian Supplement for calculating specified DRWP, the Water Resistance

values listed in Table C-4 of Appendix C may be used.

Uniform Load Structural Test

The Harmonized Standard specifies that fenestration products be tested at 150% of design pressure for wind (specified wind load)

and that skylights and roof windows be tested at 200% of design pressure for snow (specified snow load). With the change in the

British Columbia Building Code 2006 to a 1-in-50 return period for wind load, a factor of 1.4 rather than 1.5 is now applied for

wind. The British Columbia Building Code has traditionally applied a factor of 1.5 rather than 2.0 for snow. Incorporating these

lower load factors into the Code requirements for fenestration would better reflect acceptable minimum performance levels;

however, this has not been done in order to avoid adding complexity to the Code, to recognize the benefits of Canada-US

harmonization, and to recognize that differentiation of products that meet the Canadian versus the US requirements would add

complexity for manufacturers, designers, specifiers and regulatory officials.

The required design pressure and Performance Grade (PG) rating of doors and windows has been listed for each of the geographic

locations found in the Code in Table C-4. These may be used as an alternative to the specified wind load calculations in the

Canadian Supplement.

Condensation Resistance

The Harmonized Standard identifies three test procedures that can be used to determine the condensation resistance of windows

and doors. Only the physical test procedure given in CSA A440.2, “Fenestration Energy Performance” can be used to establish

Temperature Index (I) values. Computer simulation tools can also be used to estimate the relative condensation resistance of

windows, but these methods employ different expressions of performance known as Condensation Resistance Factors (CR). I and

CR values are not interchangeable.

Where removable multiple glazing panels (RMGP) are installed on the inside of a window, care should be taken to hermetically

seal the RMGP against the leakage of moisture-laden air from the interior into the cavity on the exterior of the RMGP because the

moisture transported by the air could lead to significant condensation on the interior surface of the outside glazing.

Basement Windows

Clause 12.4.2, Basement Windows, of the Harmonized Standard refers to products that are intended to meet Code requirements

for ventilation and emergency egress. The minimum test size of 800 mm × 360 mm (total area of 0.288 m

) specified in the

standard will not provide the minimum openable area required by the Code for bedrooms (i.e. 0.35 m

with no dimension less

than 380 mm) and the means to provide minimum open area identified in the standard is inconsistent with the requirements of

the Code (see Subsection 9.9.10. for bedroom windows). The minimum test size specified in the standard will also not provide

the minimum ventilation area of 0.28 m

required for non-heating-season natural ventilation (see Article 9.32.2.2.).

Performance of Doors: Limited Water Ingress Control

While the control of precipitation ingress is a performance requirement for exterior doors, side-hinged doors can comply with the

referenced standard, AAMA/WDMA/CSA 101/I.S.2/A440, “NAFS – North American Fenestration Standard/Specification for

Windows, Doors, and Skylights,” when tested at a pressure differential of 0 Pa (0.0 psf) or higher, but less than the minimum test

pressure required for the indicated performance class and performance grade. Such doors are identified with a “Limited Water”

(LW) rating on the product label.

Conditions suitable for the installation of an LW rated door are identified in Sentence 9.7.4.2.(2).

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.7.4.3.(2) Performance Requirements. If the option of calculating design pressure performance grade and water

resistance values using the Canadian Supplement is chosen, the DRWP values in Table A.1 of that standard must be used for all

buildings within the scope of Part 9 of the BC Building Code. This requirement applies whether the windows, doors and skylights are

designed to conform to Article 9.7.4.2. or to Part 5.

A-9.7.5.2.(1) Forced Entry Via Glazing in Doors and Sidelights. There is no mandatory requirement that special glass

be used in doors or sidelights, primarily because of cost. It is, however, a common method of forced entry to break glass in doors and

sidelights to gain access to door hardware and unlock the door from the inside. Although insulated glass provides increased resistance

over single glazing, the highest resistance is provided by laminated glass. Tempered glass, while stronger against static loads, is prone to

shattering under high, concentrated impact loads.

Figure A-9.7.5.2.(1)

Combined laminated/annealed glazing

Laminated glass is more expensive than annealed glass and must be used in greater thicknesses. Figure A-9.7.5.2.(1) shows an insulated

sidelight made of one pane of laminated glass and one pane of annealed glass. This method reduces the cost premium that would result

if both panes were laminated.

Consideration should be given to using laminated glazing in doors and accompanying sidelights regulated by Article 9.6.1.3., in

windows located within 900 mm of locks in such doors, and in basement windows.

Underwriters’ Laboratories of Canada have produced ULC-S332, “Burglary Resisting Glazing Material,” which provides a test

procedure to evaluate the resistance of glazing to attacks by thieves. While it is principally intended for plate glass show windows,

it may be of value for residential purposes.

A-9.7.5.2.(6) Door Fasteners. The purpose of the requirement for 30 mm screw penetration into solid wood is to prevent the

door from being dislodged from the jamb due to impact forces. It is not the intent to prohibit other types of hinges or strikeplates that

are specially designed to provide equal or greater protection.

A-9.7.5.2.(8) Hinged Doors. Methods of satisfying this Sentence include either using non-removable pin hinges or modifying

standard hinges by screw fastening a metal pin in a screw hole in one half of the top and bottom hinges. When the door is closed,

the projecting portion of the pin engages in the corresponding screw hole in the other half of the hinge and then, even if the hinge pin

is taken out, the door cannot be removed.

A-9.7.5.3.(1) Resistance of Windows to Forced Entry. Although this Sentence only applies to windows within 2 m of

adjacent ground level, certain house and site features, such as balconies or canopy roofs, allow for easy access to windows at higher

elevations. Consideration should be given to specifying break-in resistant windows in such locations.

This Sentence does not apply to windows that do not serve the interior of the dwelling unit, such as windows to garages, sun rooms or

greenhouses, provided connections between these spaces and the dwelling unit are secure.

One method that is often used to improve the resistance of windows to forced entry is the installation of metal “security bars.”

However, while many such installations are effective in increasing resistance to forced entry, they may also reduce or eliminate the

usefulness of the window as an exit in case of fire or other emergency that prevents use of the normal building exits. Indeed, unless

such devices are easily openable from the inside, their installation in some cases would contravene the requirements of

Article 9.9.10.1., which requires every bedroom that does not have an exterior door to have at least one window that is large enough

and easy enough to open that it can be used as an exit in case of emergency. Thus an acceptable security bar system should be easy to

open from the inside while still providing increased resistance to entry from the outside.

1 x 6 mm laminated glass

1 x 6 mm annealed glass

spacer

EG00315B

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.8.4. Tread Configurations. The Code distinguishes four principal types of stair treads:

• rectangular treads, which are found in straight flights;

• tapered treads, which are found in curved flights, (the term tapered tread also includes winders)

; and

winders are described in Note A-9.8.4.6.See Figure A-9.8.4.-A.

Figure A-9.8.4.-A

Types of treads

Articles 9.8.4.1. to 9.8.4.8. specify various dimensional limits for steps. Figure A-9.8.4.-B illustrates the elements of a step and how

these are to be measured.

Figure A-9.8.4.-B

Elements of steps and their measurement

Rectangular treads

Tapered treads

Winders

EG02055D

30º

45º

EG00689A

tread depth:

measured nosing to riser

run:

measured

nosing to nosing

rise:

measured

nosing to nosing

top of nosing

with rounded or

bevelled edge

6 mm to 14 mm

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.8.4.6. Winders. Where a stair must turn, the safest method of incorporating the turn is to use a landing. Within a dwelling

unit, however, where occupants are familiar with their environment, winders are an acceptable method of reducing the amount of

floor area devoted to the stair and have not been shown to be more hazardous than a straight run of steps. Nevertheless, care is required

to ensure that winders are as safe as possible. Experience has shown that 30° winders are the best compromise and require the least

change in the natural gait of the stair user; 45° winders are also acceptable, as they are wider. The Code permits only these two angles.

Although it is normal Code practice to specify upper and lower limits, in this case it is necessary to limit the winders to specific angles

with no tolerance above or below these angles other than normal construction tolerances. One result of this requirement is that

winder-type turns in stairs are limited to 30° or 45° (1 winder), 60° (2 winders), or 90° (2 or 3 winders). See Figure A-9.8.4.6.

Figure A-9.8.4.6.

Winders

A-9.8.4.8. Tread Nosings. A sloped or beveled edge on tread nosings will make the tread more visible through light modeling.

The sloped portion of the nosing must not be too wide so as to reduce the risk of slipping of the foot. See Figure A-9.8.4.-B.

A-9.8.7.1.(2) Wider Stairs than Required. The intent of Sentence 9.8.7.1.(2) is that handrails be installed in relation to the

required stair

width only, regardless of the actual width of the stair and ramp. The required handrails are provided along the assumed

natural path of travel to, from

and within the building.

A-9.8.7.2. Continuity of Handrails. The guidance and support provided by handrails is particularly important at the

beginning and end of ramps and flights of stairs and at changes in direction such as at landings and winders.

The intent of the requirement in Sentence (2) for handrails to be continuous throughout the length of the stair is that the handrail be

continuous from the bottom riser to the top riser of the stair. (See Figure A-9.8.7.2.)

For stairs or ramps serving a single dwelling unit, the intent of the requirement for handrails to be continuous throughout the length of

the flight is that the handrail be continuous from the bottom riser to the top riser of the flight. The required handrail may start back

from the bottom riser only if it is supported by a newel post or volute installed on the bottom tread. (See Figure A-9.8.7.2.)

With regard to stairs serving a single dwelling unit, the handrail may terminate at landings.

In the case of stairs within dwelling units that incorporate winders, the handrail should be configured so that it will in fact provide

guidance and support to the stair user throughout the turn through the winder.

200

150

200

min

255

min

255

155

200

30°

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure A-9.8.7.2.

Continuity of handrails at the top and bottom of stairs and flights

Note to Figure A-9.8.7.2.:

(1) See Article 9.8.7.1. to determine the number of handrails required. Some stairs will require only one, while some will require two or more.

A-9.8.7.3.(1) Termination of Handrails. Handrails are required to be installed so as not to obstruct pedestrian travel.

To achieve this end, the rail should not extend so far into a hallway as to reduce the clear width of the hallway to less than the required

width. Where the stair terminates in a room or other space, likely paths of travel through that room or space should be assessed to

ensure that any projection of the handrail beyond the end of the stair will not interfere with pedestrian travel. As extensions of

handrails beyond the first and last riser are not required in dwelling units (see Sentence 9.8.7.3.(2)) and as occupants of dwellings are

generally familiar with their surroundings, the design of dwellings would not generally be affected by this requirement.

Handrails are also required to terminate in a manner that will not create a safety hazard to blind or visually impaired persons, children

whose heads may be at the same height as the end of the rail, or persons wearing loose clothing or carrying items that might catch on

the end of the rail. One approach to reducing potential hazards is returning the handrail to a wall, floor or post. Again, within dwelling

units, where occupants are generally familiar with their surroundings, returning the handrail to a wall, floor or post may not be

necessary. For example, where the handrail is fastened to a wall and does not project past the wall into a hallway or other space,

a reasonable degree of safety is assumed to be provided; other alternatives may provide an equivalent level of protection.

A-9.8.7.3.(2) Handrail Extensions. As noted in Note A-9.8.7.2., the guidance and support provided by handrails is

particularly important at the beginning and end of ramps and flights of stairs and at changes in direction. The extended handrail

provides guidance and allows users to steady themselves upon entering or leaving a ramp or flight of stairs. Such extensions are

particularly useful to visually-impaired persons, and persons with physical disabilities or who are encumbered in their use of the stairs

or ramp.

(b) Stair serving a single dwelling unit

or a house with a secondary suite

(including their common spaces):

handrails continuous through length

of flight

winders are part of a stair flight and

are not considered a change in

direction

See NBC Article 9.8.7.1. to determine

the number of handrails required.

Some stairs will require only one

while some will require two or more.

(a) Stair serving other than a single dwelling

unit or a house with a secondary suite

(including their common spaces): handrails

continuous through length of stair

interruption

permitted

at door

interruption permitted at

door and at newel posts

at changes in direction

interruption permitted at

landing and at newel posts

at changes in direction

minimum extent of handrail where handrail

is required

newel post

top top

top

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.8.7.4. Height of Handrails. Figure A-9.8.7.4. illustrates how to measure handrail height.

Figure A-9.8.7.4.

Measuring handrail height

A-9.8.7.5.(2) Handrail Sections. Handrails are intended to provide guidance and support to stair users. To fulfil this intent,

handrails must be “graspable.”

The graspable portion of a handrail should allow a person to comfortably and firmly grab hold by allowing their fingers and thumb to

curl under part or all of the handrail. Where the configuration or dimensions of the handrail do not allow a person’s fingers and thumb

to reach the bottom of it, recesses that are sufficiently wide and deep to accommodate a person’s fingers and thumb must be provided

on both sides of the handrail, at the bottom of the graspable portion, which must not have any sharp edges.

A-9.8.7.7. Attachment of Handrails. Handrails are intended to provide guidance and support to the stair user and to arrest

falls. The loads on handrails may therefore be considerable. The attachment of handrails serving a single dwelling unit may be accepted

on the basis of experience or structural design.

A-9.8.8.1. Required Guards. The requirements relating to guards stated in Part 9 are based on the premise that, wherever

there is a difference in elevation of 600 mm or more between two floors, or between a floor or other surface to which access is provided

for other than maintenance purposes and the next lower surface, the risk of injury in a fall from the higher surface is sufficient to

warrant the installation of some kind of barrier to reduce the chances of such a fall. A wall along the edge of the higher surface will

obviously prevent such a fall, provided the wall is sufficiently strong that a person cannot fall through it. Where there is no wall, a

guard must be installed. Because guards clearly provide less protection than walls, additional requirements apply to guards to ensure

that a minimum level of protection is provided. These relate to the characteristics described in Notes A-9.8.8.3., A-9.8.8.5.(1) and (2),

A-9.8.8.5.(3) and A-9.8.8.6.(1).

Examples of such surfaces where the difference in elevation could exceed 600 mm and consequently where guards would be required

include, but are not limited to, landings, porches, balconies, mezzanines, galleries, and raised walkways. Especially in exterior settings,

surfaces adjacent to walking surfaces, stairs or ramps often are not parallel to the walking surface or the surface of the treads or ramps.

Consequently, the walking surface, stair or ramp may need protection in some locations but not in others. (See Figure A-9.8.8.1.)

In some instances, grades are artificially raised close to walking surfaces, stairs or ramps to avoid installing guards. This provides little

or no protection for the users. That is why the requirements specify differences in elevation not only immediately adjacent to the

construction but also for a distance of 1200 mm from it by requiring that the slope of the ground be within certain limits.

(See Figure A-9.8.8.1.)

EG00322B

handrail

vertical

measurement

of height

straight line tangent

to tread nosing

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure A-9.8.8.1.

Required locations of guards

A-9.8.8.1.(4) Height of Window Sills above Floors or Ground. The primary intent of the requirement is to minimize

the likelihood of small children falling significant heights from open windows. Reflecting reported cases, the requirement applies only

to dwelling units and generally those located on the second floor or higher of residential or mixed use buildings where the windows are

essentially free-swinging or free-sliding.

Free-swinging or free-sliding means that a window that has been cracked open can be opened further by simply pushing on the

openable part of the window. Care must be taken in selecting windows, as some with special operating hardware can still be opened

further by simply pushing on the window.

Casement windows with crank operators would be considered to conform to Clause (4)(b). To provide additional safety, where slightly

older children are involved, occupants can easily remove the crank handles from these windows. Awning windows with scissor

hardware, however, may not keep the window from swinging open once it is unlatched. Hopper windows would be affected only if an

opening is created at the bottom as well as at the top of the window. The requirement will impact primarily on the use of sliding

windows which do not incorporate devices in their construction that can be used to limit the openable area of the window.

The 100 mm opening limit is consistent with widths of openings that small children can fall through. It is only invoked, however,

where the other dimension of the opening is more than 380 mm. Again, care must be taken in selecting a window. At some position,

scissor hardware on an awning window may break up the open area such that there is no unobstructed opening with dimensions

greater than 380 mm and 100 mm. At another position, however, though the window is not open much more, the hardware may not

adequately break up the opening. The 450 mm height off the floor recognizes that furniture is often placed under windows and small

children are often good climbers.

A-9.8.8.2. Loads on Guards. Guards must be constructed so as to be strong enough to protect persons from falling under

normal use. Many guards installed in dwelling units or on exterior stairs serving one or two dwelling units have demonstrated

acceptable performance over time. The loading described in the first row of Table 9.8.8.2. is intended to be consistent with the

performance provided by these guards. Examples of guard construction presented in the “2012 Building Code Compendium,

Volume 2, Supplementary Standard SB-7, Guards for Housing and Small Buildings” meet the criteria set in the National Building

Code for loads on guards, including the more stringent requirements of Sentences 9.8.8.2.(1) and (2).

The load on guards within dwelling units, or on exterior guards serving not more than two dwelling units, is to be imposed over an

area of the guard such that, where standard balusters are used and installed at the maximum 100 mm spacing permitted for required

guards, 3 balusters will be engaged. Where the balusters are wider, only two may be engaged unless they are spaced closer together.

Where the guard is not required, and balusters are installed more than 100 mm apart, fewer balusters may be required to carry the

imposed load.

A-9.8.8.3. Minimum Heights. Guard heights are generally based on the waist heights of average persons. Generally, lower

heights are permitted in dwelling units because the occupants become familiar with the potential hazards, and situations which lead to

pushing and jostling under crowded conditions are less likely to arise.

A-9.8.8.5.(1) and (2) Risk of Falling through Guards. The risk of falling through a guard is especially prevalent for

children. Therefore the requirements are stringent for guards in all buildings except industrial buildings, where children are unlikely

to be present except under strict supervision.

600 mm

1 200 mm

slope is greater

than 1 in 2

EG02058A

handrail

required

guard required

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.8.8.5.(3) Risk of Children Getting Their Head Stuck between Balusters. The requirements to prevent children

falling through guards also serve to provide adequate protection against this problem. However, guards are often installed where they

are not required by the Code; i.e., in places where the difference in elevation is less than 600 mm. In these cases, there is no need to

require the openings between balusters to be less than 100 mm. However, there is a range of openings between 100 mm and 200 mm

in which children can get their head stuck. Therefore, openings in this range are not permitted except in buildings of industrial

occupancy, where children are unlikely to be present except under strict supervision.

A-9.8.8.6.(1) Configuration of Members, Attachments or Openings in Guards so as to not Facilitate

Climbing. Some configurations of members, attachments or openings may be part of a guard design and still comply with

Sentence 9.8.8.6.(1). Figures A-9.8.8.6.(1)-A to A-9.8.8.6.(1)-D present a few examples of designs that are considered to not

facilitate climbing.

Protrusions that are greater than 450 mm apart horizontally and vertically are considered sufficiently far apart to reduce the likelihood

that young children will be able to get a handhold or toehold on the protrusions and climb the guard.

Figure A-9.8.8.6.(1)-A

Example of minimum horizontal and vertical clearances between protrusions in guards

Protrusions that present a horizontal offset of 15 mm or less are considered to not provide a sufficient foot purchase to

facilitate climbing.

> 450 mm

900 mm

140 mm

GG00176A

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure A-9.8.8.6.(1)-B

Examples of maximum horizontal offset of protrusions in guards

A guard incorporating spaces that are not more than 45 mm wide by 20 mm high is considered to not facilitate climbing because the

spaces are too small to provide a toehold.

Figure A-9.8.8.6.(1)-C

Example of a guard with spaces created by the protruding elements that are not more than 45 mm wide and 20 mm high

EG00746A

≤15 mm offset

900 mm

140 mm

900 mm

140 mm

≤ 45 mm

≤ 20 mm

GG00178A

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Protrusions that present more than a 2-in-1 slope on the offset are considered to not facilitate climbing because such a slope is

considered too steep to provide adequate footing.

Figure A-9.8.8.6.(1)-D

Example of guard protrusions with a slope greater than 2 in 1

A-9.9.4.5.(1) Openings in Exterior Walls of Exits.

Figure A-9.9.4.5.(1)

Protection of openings in exterior walls of exits

> 2

GG00179A

900 mm

140 mm

• > 3 m horizontally

• opening in building > 2 m

above openings in the exit

³ 135˚

< 135˚

no protection

required

no protection

required

openings within 3 m horizontally and

within 2 m above openings in the exit

< 135˚

protection

required

protection

required

EC01221A

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.9.8.4.(1) Independent and Remote Exits. Subsection 9.9.8. requires that some floor areas have more than one exit.

The intent is to ensure that, if one exit is made untenable or inaccessible by a fire, or its exterior door is blocked by an exterior

incident, one or more other exits will be available to permit the occupants to escape. However, if the exits are close together, all exits

might be made untenable or inaccessible by the same fire. Sentence 9.9.8.4.(1) therefore requires at least two of the exits to be located

remotely from each other. This is not a problem in many buildings falling under Part 9. For instance, apartment buildings usually have

exits located at either end of long corridors. However, in other types of buildings (e.g. dormitory and college residence buildings)

this is often difficult to accomplish and problems arise in interpreting the meaning of the word “remote.” Article 3.4.2.3. is more

specific, generally requiring the distance between exits to be one half the diagonal dimension of the floor area or at least 9 m. However,

it is felt that such criteria would be too restrictive to impose on the design of all the smaller buildings which come under Part 9.

Nevertheless, the exits should be placed as far apart as possible and the Part 3 criteria should be used as a target. Designs in which the

exits are so close together that they will obviously both become contaminated in the event of a fire are not acceptable.

A-9.9.10.1.(1) Escape Windows from Bedrooms. Sentence 9.9.10.1.(1) generally requires every bedroom in an

unsprinklered suite to have at least one window or door opening to the outside that is large enough and easy enough to open so that it

can be used as an exit in the event that a fire prevents use of the building’s normal exits. The minimum unobstructed opening specified

for escape windows must be achievable using only the normal window operating procedure. The escape path must not go through nor

open onto another room, floor or space.

Where a bedroom is located in an unsprinklered suite in a basement, an escape window or door must be located in the bedroom. It is

not sufficient to rely on egress through other basement space to another escape window or door.

Window Height

The Article does not set a maximum sill height for escape windows; it is therefore possible to install a window or skylight that

satisfies the requirements of the Article but defeats the Article’s intent by virtue of being so high that it cannot be reached for exit

purposes. It is recommended that the sills of windows intended for use as emergency exits be not higher than 1.5 m above the

floor. However, it is sometimes difficult to avoid having a higher sill: on skylights and windows in basement bedrooms for

example. In these cases, it is recommended that access to the window be improved by some means such as built-in furniture

installed below the window.

Figure A-9.9.10.1.(1)

Built-in furniture to improve access to a window

EC00319B

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.9.10.1.(2) Bedroom Window Opening Areas and Dimensions. Although the minimum opening dimensions

required for height and width are 380 mm, a window opening that is 380 mm by 380 mm would not comply with the minimum area

requirements. (See Figure A-9.9.10.1.(2))

Figure A-9.9.10.1.(2)

Window opening areas and dimensions

A-9.9.10.1.(3) Window Opening into a Window Well. Sentence 9.9.10.1.(3) specifies that there must be a minimum

clearance of 760 mm in front of designated escape windows to allow persons to escape a basement bedroom in an emergency.

This specified minimum clearance is consistent with the minimum required width for means of egress from a floor area

(see Article 9.9.5.5.) and the minimum required width for path of travel on exit stairs (see Article 9.9.6.1.). It is considered the

smallest acceptable clearance between the escape window and the facing wall of the window well that can accommodate persons trying

to escape a bedroom in an emergency given that they are not moving straight through the window but must move outward and up,

and must have sufficient space to change body orientation.

Once this clearance is provided, no additional clearance is needed for windows with sliders, casements, or inward-opening awnings.

However, for windows with outward-opening awnings, additional clearance is needed to provide the required 760 mm beyond the

outer edge of the sash. (See Figure A-9.9.10.1.(3).)

Depending on the likelihood of snow accumulation in the window well, it could be difficult – if not impossible – to escape in an

emergency. The window well should be designed to provide sufficient clear space for a person to get out the window and then out the

well, taking into account potential snow accumulation.

Hopper windows (bottom-hinged operators) should not be used as escape windows in cases where the occupants would be required to

climb over the glass.

(a) conforms to opening height

and width requirements; does

not conform to opening area

requirements

(b) and (c) conform to height, width and

opening area requirements

380 mm

Opening

area

0.144 m

(a)

380 mm

920 mm

Opening

area

0.35 m

(b)

EG00318B

592 mm

Opening

area

0.35 m

(c)

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure A-9.9.10.1.(3)

Windows providing a means of escape that open into a window well

A-9.10.1.4.(1) Commercial Cooking Equipment. Part 6 refers to NFPA 96, “Ventilation Control and Fire Protection of

Commercial Cooking Operations,” which in turn references “Commercial Cooking Equipment.” However, the deciding factor as to

whether or not NFPA 96 applies is the potential for production of grease-laden vapours and smoke, rather than the type of equipment

used. While NFPA 96 does not apply to domestic equipment for normal residential family use, it should apply to domestic equipment

used in commercial, industrial, institutional and similar cooking applications where the potential for the production of smoke and

grease-laden vapours exceeds that for normal residential family use.

A-9.10.3.1. Fire and Sound Resistance of Building Assemblies. Tables 9.10.3.1.-A and 9.10.3.1.-B have been

developed from information gathered from tests. While a large number of the assemblies listed were tested, the fire-resistance and

acoustical ratings for others were assigned on the basis of extrapolation of information from tests of similar assemblies. Where there

was enough confidence relative to the fire performance of an assembly, the fire-resistance ratings were assigned relative to the

commonly used minimum ratings of 30 min, 45 min and 1 h, including a designation of “< 30 min” for assemblies that are known

not to meet the minimum 30-minute rating. Where there was not enough comparative information on an assembly to assign to it a

rating with confidence, its value in the tables has been left blank (hyphen), indicating that its rating remains to be assessed through

another means. Future work is planned to develop much of this additional information.

These tables are provided only for the convenience of Code users and do not limit the number of assemblies permitted to those in the

tables. Assemblies not listed or not given a rating in these tables are equally acceptable provided their fire and sound resistance can be

demonstrated to meet the above-noted requirements either on the basis of tests referred to in Article 9.10.3.1. and Subsection 9.11.1.

or by using the data in Appendix D, Fire-Performance Ratings. It should be noted, however, that Tables 9.10.3.1.-A and 9.10.3.1.-B

are not based on the same assumptions as those used in Appendix D. Assemblies in Tables 9.10.3.1.-A and 9.10.3.1.-B are described

through their generic descriptions and variants and include details given in the notes to the tables. Assumptions for Appendix D

include different construction details that must be followed rigorously for the calculated ratings to be expected. These are two different

methods of choosing assemblies that meet required fire ratings.

Table 9.10.3.1.-B presents fire-resistance and acoustical ratings for floor, ceiling and roof assemblies. The fire-resistance ratings are

appropriate for all assemblies conforming to the construction specifications given in Table 9.10.3.1.-B, including applicable table

notes. Acoustical ratings for assemblies decrease with decreasing depth and decreasing separation of the structural members; the values

listed for sound transmission class and impact insulation class are suitable for the minimum depth of structural members identified in

the description, including applicable table notes, and for structural member spacing of 305 mm o.c., unless other values are explicitly

listed for the assembly. Adjustments to the acoustical ratings to allow for the benefit of deeper or more widely spaced structural

members are given in Table Notes (9) and (10).

EG00688A

760

grade

basement

760

basement

window

well

760 mm

window

well

grade

window

well

grade

basement

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Figure A-9.10.3.1.-A

Single layer butt joint details

Notes to Figure A-9.10.3.1.-A:

(1) Figure is for illustrative purposes only and is not to scale.

(2) The structural member can be any one of the types described in the Table.

(3) Adjacent gypsum board butt ends are attached to separate resilient channels using regular Type S screws, located a minimum of 38 mm from

the butt end.

Figure A-9.10.3.1.-B

Double layer butt joint details

Notes to Figure A-9.10.3.1.-B:

(1) Figure is for illustrative purposes only and is not to scale.

(2) The structural member can be any one of the types described in the Table.

(3) Base layer butt ends can be attached to a single resilient channel using regular Type S screws.

(4) Type G screws measuring a minimum of 32 mm in length and located a minimum of 38 mm from the butt end are used to fasten the butt ends

of the face layer to the base layer.

Figure A-9.10.3.1.-C

Example of steel furring channel

Note to Figure A-9.10.3.1.-C:

(1) Figure is for illustrative purposes only and is not to scale.

GG00160A

GG00161A

GG00172A

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure A-9.10.3.1.-D

Example of resilient metal channel

Note to Figure A-9.10.3.1.-D:

(1) Figure is for illustrative purposes only and is not to scale.

A-9.10.4.1.(4) Mezzanines Not Considered as Storeys. Mezzanines increase the occupant load and the fire load of the

storey of which they are part. To take the added occupant load into account for the purpose of evaluating other requirements that are

dependent on this criteria, their floor area is added to the floor area of the storey.

A-9.10.9.6.(1) Penetration of Fire-Rated Assemblies by Service Equipment. This Sentence, together with

Article 3.1.9.1., is intended to ensure that the integrity of fire-rated assemblies is maintained where they are penetrated by various

types of service equipment.

For buildings regulated by the requirements in Part 3, fire stop materials used to seal openings around building services, such as pipes,

ducts and electrical outlet boxes, must meet a minimum level of performance demonstrated by standard test criteria.

This is different from the approach in Part 9. Because of the type of construction normally used for buildings regulated by the

requirements in Part 9, it is assumed that this requirement is satisfied by the use of generic fire stop materials such as mineral wool,

gypsum plaster or Portland cement mortar.

A-9.10.9.16.(4) Separation between Dwelling Units and Storage or Repair Garages. The gas-tight barrier

between a dwelling unit and an attached garage is intended to provide protection against the entry of carbon monoxide and gasoline

fumes into the dwelling unit. Building assemblies incorporating an air barrier system will perform adequately with respect to gas

tightness, provided all joints in the airtight material are sealed and reasonable care is exercised where the wall or ceiling is pierced by

building services. Where a garage is open to the adjacent attic space above the dwelling unit it serves, a gas-tight barrier in the ceiling of

the dwelling unit will also provide protection. Unit masonry walls forming the separation between a dwelling unit and an adjacent

garage should be provided with two coats of sealer or plaster, or covered with gypsum board on the side of the wall exposed to the

garage. All joints must be sealed to ensure continuity of the barrier. (See also Sentences 9.25.3.3.(3) to (8).)

GG00173A

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.10.12.4.(1) Protection of Overhang of Common Roof Space.

Figure A-9.10.12.4.(1)

Protection of overhang of common roof space

A-9.10.12.4.(3) Protection at Soffits. The materials required by this Sentence to be used as protection for soffit spaces in

certain locations do not necessarily have to be the finish materials. They can be installed either behind the finishes chosen for the soffits

or in lieu of these.

A-9.10.13.2.(1) Wood Doors in Fire Separations. CAN/ULC-S113, “Wood Core Doors Meeting the Performance

Required by CAN/ULC-S104 for Twenty Minute Fire Rated Closure Assemblies,” provides construction details to enable

manufacturers to build wood core doors that will provide a 20 min fire-protection rating without the need for testing. The standard

requires each door to be marked with

1. the manufacturer’s or vendor’s name or identifying symbol,

2. the words “Fire Door,” and

3. a reference to the fire-protection rating of 20 min.

A-9.10.14.5.(1) Minor Combustible Cladding Elements. Minor elements of cladding that is required to be

noncombustible are permitted to be of combustible material, provided they are distributed over the building face and not concentrated

in one area. Examples of minor combustible cladding elements include door and window trim and some decorative elements.

A-9.10.14.5.(7) Permitted Projections. The definition of exposing building face provided in Sentence 1.4.1.2.(1) of

Division A refers to “that part of the exterior wall of a building … or, where a building is divided into fire compartments, the exterior

wall of a fire compartment …” Because the exposing building face is defined with respect to the exterior wall, projections from

exposing building faces are elements that do not incorporate exterior walls. Depending on their specific configurations, examples of

constructions that would normally be permitted by Sentence 9.10.14.5.(7) are balconies, platforms, canopies, eave projections and

stairs. However, if a balcony, platform or stair is enclosed, its exterior wall would become part of an exposing building face and the

construction could not be considered to be a projection from the exposing building face.

1.2 m

area to be protected

2.5 m

or less

EC00357B

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.10.14.5.(8) Protection at Projections. Sentence 9.10.14.5.(7) permits certain projections from exposing building faces

where the projections do not have exterior walls and thus clearly do not constitute part of the exposing building face.

Sentence 9.10.14.5.(8) refers to other types of projections from the exposing building face, such as those for fireplaces and chimneys.

It is recognized that these types present more vertical surface area compared to platforms, canopies and eave projections, and may be

enclosed by constructions that are essentially the same as exterior walls. These constructions, however, do not enclose habitable space,

are of limited width and may not extend a full storey in height. Consequently, Sentence (8) allows these projections beyond the

exposing building face of buildings identified in Sentence (6), provided additional fire protection is installed on the projection.

Figure A-9.10.14.5.(8) illustrates projections that extend within 1.2 m of the property line where additional protection must be

provided. Where a projection extends within 0.6 m of the property line, it must be protected to the same degree as an exposing

building face that has a limiting distance of less than 0.6 m. Where a projection extends to less than 1.2 m but not less than 0.6m of

the property line, it must be protected to the same degree as an exposing building face that has a limiting distance of less than 1.2 m.

Protection is also required on the underside of the projection where the projection is more than 0.6 m above finished ground level,

measured at the exposing building face.

Figure A-9.10.14.5.(8)

Protection at projections

EG00694D

space

enclosed by

projection is

not habitable

space

enclosed by

projection is

not habitable

space

enclosed by

projection is

not habitable

space

> 0.6 m

< 1.2 m

Section

PlanPlan

normal cladding-sheathing assembly

cladding-sheathing assemblies

providing additional fire protection

}

< 1.2 m

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.10.14.5.(11) and 9.10.15.5.(10) Roof Soffit Projections.

Figure A-9.10.14.5.(11) and 9.10.15.5.(10)

Roof soffit projections

Notes to Figure A-9.10.14.5.(11) and 9.10.15.5.(10):

(1) See Sentences 3.2.3.6.(2), 9.10.14.5.(9) and 9.10.15.5.(8).

(2) See Sentences 3.2.3.6.(3), 9.10.14.5.(10) and 9.10.15.5.(9).

(3) See Sentences 3.2.3.6.(4), 9.10.14.5.(11) and 9.10.15.5.(10).

A-9.10.15.4.(2) Staggered or Skewed Exposing Building Faces of Houses. Studies at the National Fire Laboratory

of the National Research Council have shown that, where an exposing building face is stepped back from the property line or is at an

angle to the property line, it is possible to increase the percentage of glazing in those portions of the exposing building face further

from the property line without increasing the amount of radiated energy that would reach the property line in the event of a fire in

such a building. Figures A-9.10.15.4.(2)-A, A-9.10.15.4.(2)-B and A-9.10.15.4.(2)-C show how Sentences 9.10.15.4.(1) and (2),

and 9.10.15.5.(2) and (3) can be applied to exposing building faces that are stepped back from or not parallel to the property line.

The following procedure can be used to establish the maximum permitted area of glazed openings for such facades:

1. Calculate the total area of the exposing building face, i.e. facade of the fire compartment, as described in the definition of

exposing building face.

2. Identify the portions into which the exposing building face is to be divided. It can be divided in any number of portions, not

necessarily of equal size.

3. Measure the limiting distance for each portion. The limiting distance is measured along a line perpendicular to the wall surface

from the point closest to the property line.

4. Establish the line in Table 9.10.15.4. from which the maximum permitted percentage area of glazed openings will be read.

The selection of the line depends on the maximum area of exposing building face for the whole fire compartment, including all

portions, as determined in Step 1.

5. On that line, read the maximum percentage area of glazed openings permitted in each portion of the exposing building face

according to the limiting distance for that portion.

a) Projecting roof soffit not

allowed to be constructed

(1)

b) Roof soffit must not project to

less than 0.45 m from the

property line

(2)

c) Roof soffit permitted to project up to

property line, where it faces a

street, lane or public thoroughfare,

regardless of the limiting distance

(3)

no roof

soffits

≥ 0.45 m

LD ≤ 0.45 m

LD > 0.45 m

property line

centre line of a street, lane or public thoroughfare

property line

EG01393A

LD = limiting distance

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

6. Calculate the maximum area of glazed openings permitted in each portion. The area is calculated from the percentage found

applied to the area of that portion.

Table 9.10.15.4. is used to read the maximum area of glazed openings: this means that the opaque portion of doors does not have to be

counted as for other types of buildings.

Note that this Note and the Figures do not describe or illustrate maximum permitted concentrated area or spacing of individual glazed

openings, or limits on the location of dividing lines between portions of the exposing building face depending on the location of these

openings with respect to interior rooms or spaces. See Sentences 9.10.15.2.(2) and 9.10.15.4.(2) to (4) for the applicable

requirements.

Figure A-9.10.15.4.(2)-A

Example of determination of criteria for the exposing building face of a staggered wall of a house

Notes to Figure A-9.10.15.4.(2)-A:

(1) See Sentence 9.10.15.5.(2).

(2) See Sentence 9.10.15.5.(3).

(3) See Table 9.10.15.4., Subclause 9.10.15.2.(1)(b)(iii) and Sentence 9.10.15.4.(2).

noncombustible no limits

0% 7% 1 1 %

7.6 m 6 m 3 m

required not required

no limits

not required

3 x 2.4 x 0.07

= 0.50 m

6 x 2.4 x 0. 1 1 = 1.58 m

EG00417D

Permitted aggregate

area of glazed openings

Permitted % of

glazed openings

Type of cladding

45 min fire-resistance

rating

Property Line

Exposing

Building Face:

- T otal length: 16.6 m

- Height: 2.4 m

- T otal area:

16.6 x 2.4 = 40 m

limiting distance

= 0.4 m

limiting distance

= 1.2 m

limiting distance

= 2.0 m

(1)

(2) (2)

(2)

(3)

(1)

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Figure A-9.10.15.4.(2)-B

Example of determination of criteria for the exposing building face of a skewed wall of a house with some arbitrary division of the wall

Notes to Figure A-9.10.15.4.(2)-B:

(1) See Sentence 9.10.15.5.(2).

(2) See Sentence 9.10.15.5.(3).

(3) See Table 9.10.15.4., Subclause 9.10.15.2.(1)(b)(iii) and Sentence 9.10.15.4.(2).

(4) To simplify the calculations, choose the column for the lesser limiting distance nearest to the actual limiting distance. Interpolation for limiting

distance is also acceptable and may result in a slightly larger permitted area of glazed openings. Interpolation can only be used for limiting

distances greater than 1.2 m.

required required not required not required

not required

no limits no limits no limits noncombustible

noncom-

bustible

0% 100% 28%9%0%

0 0 5.0 x 2.4 x 0.09

= 1.08 m

7.0 x 2.4 x 0.28

= 4.70 m

3.0 x 2.4 x 1.0

= 7.2 m

EG00378D

Permitted aggregate

area of glazed openings

Permitted % of

glazed openings

Type of cladding

45 min fire-resistance

rating

3.8 m

30°

Property Line

Exposing

Building Face:

- T otal length: 20.8 m

- Height: 2.4 m

T otal area:

20.8 x 2.4 = 50 m

limiting distance

= 0.5 m

limiting

distance

= 0.58 m

limiting

distance

= 1.73 m

limiting

distance

= 4.62 m

limiting

distance

= 8.66 m

5.0 m

7.0 m

3.0 m

2.0 m

(2) (2) (2)

(3)(4)

(1) (1) (2) (2)

(2)

(1)

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure A-9.10.15.4.(2)-C

Example of determination of criteria for the exposing building face of a skewed wall of a house with a different arbitrary division of

the wall

Notes to Figure A-9.10.15.4.(2)-C:

(1) See Sentence 9.10.15.5.(2).

(2) See Sentence 9.10.15.5.(3).

(3) See Table 9.10.15.4., Subclause 9.10.15.2.(1)(b)(iii) and Sentence 9.10.15.4.(2).

(4) To simplify the calculations, choose the column for the lesser limiting distance nearest to the actual limiting distance. Interpolation for limiting

distance is also acceptable and may result in a slightly larger permitted area of glazed openings. Interpolation can only be used for limiting

distances greater than 1.2 m.

A-9.10.19.3.(1) Location of Smoke Alarms. There are two important points to bear in mind when considering where to

locate smoke alarms in dwelling units:

• The most frequent point of origin for fires in dwelling units is the living area.

• The main concern in locating smoke alarms is to provide warning to people asleep in bedrooms.

A smoke alarm located in the living area and wired so as to sound another smoke alarm located near the bedrooms is the ideal solution.

However, it is difficult to define exactly what is meant by “living area.” It is felt to be too stringent to require a smoke alarm in every

part of a dwelling unit that could conceivably be considered a “living area” (living room, family room, study, etc.).

Sentence 9.10.19.3.(1) addresses these issues by requiring at least one smoke alarm on every storey containing a sleeping room.

Thus, in a dwelling unit complying with Sentence 9.10.19.3.(1), every living area will probably be located within a reasonable distance

of a smoke alarm. Nevertheless, where a choice arises as to where on a storey to locate the required smoke alarm or alarms, one should

be located as close as possible to a living area, provided the requirements related to proximity to bedrooms are also satisfied.

A smoke alarm is not required on each level in a split-level dwelling unit as each level does not count as a separate storey. Determine the

number of storeys in a split-level dwelling unit and which levels are part of which storey as follows:

1. establish grade, which is the lowest of the average levels of finished ground adjoining each exterior wall of a building;

2. identify the first storey, which is the uppermost storey having its floor level not more than 2 m above grade;

required

noncom-

bustible

3.8 m

9.0 m

5.0 m

2.0 m

0% 7%

Permitted aggregate

area of glazed openings

Permitted % of

glazed openings

Type of cladding

45 min fire-resistance

rating

Property Line

Exposing

Building Face:

- T otal length: 20.8 m

- Height: 2.4 m

- T otal area:

20.8 x 2.4 = 50 m

limiting distance

= 0.54 m

limiting distance

= 0.62 m

limiting

distance

= 6.4 m

limiting

distance

= 9.3 m

limiting distance

= 1.2 m

required

no limits no limits

not required

no limits

not required

9.0 x 2.4 x 0.07

= 1.51 m

5.0 x 2.4 x 0.57

= 6.84 m

2.0 x 2.4 x 1.0

57%

EG00379D

30°

100%

1.0 m

= 4.8 m

(2)

(1)

(2)

(2) (2)

(1)

(3)(4)

noncombustible

(2)

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

3. identify the basement, which is the storey or storeys located below the first storey;

4. identify the second storey and, where applicable, the third storey.

As a minimum, one smoke alarm is required to be installed in each storey, preferably on the upper level of each one. As noted above,

however, when the dwelling unit contains more than one sleeping area, an alarm must be installed to serve each area. Where the

sleeping areas are on two levels of a single storey in a split-level dwelling unit, an additional smoke alarm must be installed so that both

areas are protected. See Figure A-9.10.19.3.(1).

Figure A-9.10.19.3.(1)

Two-storey split-level building

Notes to Figure A-9.10.19.3.(1):

(1) One smoke alarm required for each of the basement, first storey and second storey.

(2) An additional smoke alarm is required on the lower level of the second storey outside the sleeping rooms.

A-9.10.20.3.(1) Fire Department Access Route Modification. In addition to other considerations taken into account in

the planning of fire department access routes, special variations could be permitted for a house or residential building that is protected

with an automatic sprinkler system. The sprinkler system must be designed in accordance with the appropriate NFPA standard and

there must be assurance that water supply pressure and quantity are unlikely to fail. These considerations could apply to buildings that

are located on the sides of hills and are not conveniently accessible by roads designed for firefighting equipment and also to infill

housing units that are located behind other buildings on a given property.

A-9.10.22. Clearances from Gas, Propane and Electric Cooktops. CSA C22.1, “Canadian Electrical Code, Part I,”

which is adopted by the Electrical Safety Regulation

referenced in Article 9.34.1.1., and CSA B149.1, “Natural Gas and Propane

Installation Code,” which is adopted by the Gas Safety Regulation

referenced in Article 9.10.22.1., address clearances directly above,

in front of, behind and beside the appliance. Where side clearances are zero, the standards do not address clearances to building

elements located both above the level of the cooktop elements or burners and to the side of the appliance. Through reference to the

above noted regulations and their adopted standards

, and the requirements in Articles 9.10.22.2. and 9.10.22.3., the British Columbia

Building Code addresses all clearances. Where clearances are addressed by the British Columbia Building Code and the above noted

regulations and their adopted standards, conformance with all relevant criteria is achieved by compliance with the most

stringent criteria.

EG00676A

Not more

than 2 m

(1)

(2)

Grade

Lower 2nd storey

(with sleeping area)

Lower 1st storey

Lower basement

Upper 2nd storey

(with sleeping area)

Upper 1st storey

Upper

basement

= smoke alarm

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Installation of Microwave Ovens Over Cooktops

The minimum vertical clearances stated in Article 9.10.22.2. apply only to combustible framing, finishes and cabinets. They do

not apply to microwave ovens installed over cooktops nor to range hoods. The “Canadian Electrical Code, Part I” requires that

microwave ovens comply with CAN/CSA-C22.2 No. 150, “Microwave Ovens.” This standard includes tests to confirm that the

appliance will not present a hazard when installed according to the manufacturer’s instructions.

Figure A-9.10.22.

Clearances from cooktops to walls and cabinetry

appliance opening

horizontal or

vertical clearance

less than 450 mm -

protected

EG00380A

vertical clearance 600 mm minimum -

protected or noncombustible;

750 mm or more - unprotected

horizontal or

vertical clearance

450 mm or more -

unprotected

level of elements

or burners

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.11. Sound Transmission.

Airborne Sound

Airborne sound is transmitted between adjoining spaces directly through the separating wall, floor and ceiling assemblies and via

the junctions between these separating assemblies and the flanking assemblies.

The Sound Transmission Class (STC) rating describes the performance of the separating wall or floor/ceiling assembly, whereas

the Apparent Sound Transmission Class (ASTC) takes into consideration the performance of the separating element as well as the

flanking transmission paths. Therefore, from the occupants’ point of view, the best indicator of noise protection between two

spaces is the ASTC rating.

As a key principle, it is important to follow a “whole-system” approach when designing or constructing assemblies that separate

dwelling units because the overall sound performance of walls and floors is also influenced by fire protection measures and the

structural design of the assemblies. Likewise, changes to the construction of assemblies to meet sound transmission requirements

may have fire and structural implications. Another key principle is that enhancing the performance of the separating element does

not automatically enhance the system’s performance.

For horizontally adjoining spaces, the separating assembly is the intervening wall and the pertinent flanking surfaces include those

of the floor, ceiling, and side wall assemblies that have junctions with the separating wall assembly, normally at its four edges.

For each of these junctions, there is a set of sound transmission paths. Figure A-9.11.-A illustrates the horizontal sound

transmission paths at the junction of a separating wall with flanking floor assemblies.

Figure A-9.11.-A

Horizontal sound transmission paths at floor/wall junction

For vertically adjoining spaces, the separating assembly is the intervening floor/ceiling and the pertinent flanking surfaces include

those of the side wall assemblies in the upper and lower rooms that have junctions with the separating floor/ceiling assembly at its

edges, of which there are normally four. For each of these junctions, there is a set of sound transmission paths. Figure A-9.11.-B

illustrates the vertical sound transmission paths at the junction of a separating floor/ceiling assembly with two flanking wall

assemblies.

EG01379A

apparent

sound

transmission

class (ASTC)

direct path

(STC)

flanking paths

airborne

sound

source

flanking

floor/ceiling

assembly

separating wall assembly

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure A-9.11.-B

Vertical sound transmission paths at wall/floor junction

Control of Sound Leaks

The metrics used to characterize the sound transmission performance of assemblies separating dwelling units do not account for

the adverse effects of air leaks in those assemblies, which can transfer sound. Sound leaks can occur where a wall meets another

wall, the floor, or the ceiling. They can also occur where wall finishes are cut to allow the installation of equipment or services.

The following are examples of measures for controlling sound leaks:

• avoid back-to-back electrical outlets or medicine cabinets;

• carefully seal cracks or openings so structures are effectively airtight;

• apply sealant below the plates in stud walls, between the bottom of gypsum board and the structure behind, around all

penetrations for services and, in general, wherever there is a crack, a hole or the possibility of one developing;

• include sound-absorbing material inside the wall if not already required

The reduction of air leakage is also addressed to some extent by the smoke tightness requirements in the Code.

The calculation of and laboratory testing for STC and ASTC ratings are performed on intact assemblies having no penetrations or

doors. When measuring ASTC ratings in the field, openings can be blocked with insulation and drywall.

To verify that the required acoustical performance is being achieved, a field test can be done at an early stage of construction.

ASTM E 336, “Measurement of Airborne Sound Attenuation between Rooms in Buildings,” gives a complete measurement.

A simpler and less expensive method is presented in ASTM E 597, “Determining a Single Number Rating of Airborne Sound

Insulation for Use in Multi-Unit Building Specifications.” The rating derived from this test is usually within 2 points of the STC

obtained from ASTM E 336. It is useful for verifying performance and finding problems during construction. Alterations can

then be made prior to project completion.

airborne

sound

source

direct path

(STC)

flanking

paths

apparent sound transmission class

(ASTC)

EG01380A

separating

floor/ceiling

assembly

flanking

side wall

assemblies

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Impact Noise

Section 9.11. has no requirements for the control of impact noise transmission. However, footsteps and other impacts can cause

severe annoyance in multifamily residences. Builders concerned about quality and reducing occupant complaints will ensure that

floors are designed to minimize impact transmission. A recommended criterion is that bare floors (tested without a carpet) should

achieve an impact insulation class (IIC) of 55. Some lightweight floors that satisfy this requirement may still elicit complaints

about low frequency impact noise transmission. Adding carpet to a floor will always increase the IIC rating but will not necessarily

reduce low frequency noise transmission. Good footstep noise rejection requires fairly heavy floor slabs or floating floors.

The most frequently used test methods for impact noise are ASTM E 492, “Laboratory Measurement of Impact Sound

Transmission Through Floor-Ceiling Assemblies Using the Tapping Machine,” and ASTM E 1007, “Field Measurement of

Tapping Machine Impact Sound Transmission Through Floor-Ceiling Assemblies and Associated Support Structures.”

Machinery Noise

Elevators, garbage chutes, plumbing, fans, and heat pumps are common sources of noise in buildings. To reduce annoyance from

these, they should be placed as far as possible from sensitive areas. Vibrating parts should be isolated from the building structure

using resilient materials such as neoprene or rubber.

A-9.11.1.3.(2)(b) Control of Airborne Noise in Buildings. Tables 9.10.3.1.-A and 9.10.3.1.-B present separating

assemblies that comply with Section 9.11. However, selecting an appropriate separating assembly is only one part of the solution for

reducing airborne sound transmission between adjoining spaces: to fully address the sound performance of the whole system, flanking

assemblies must be connected to the separating assembly in accordance with Article 9.11.1.4.

A-9.11.1.4. Adjoining Constructions. Tables A-9.11.1.4.-A to A-9.11.1.4.-D present generic options for the design and

construction of junctions between separating and flanking assemblies. Constructing according to these options is likely to meet or

exceed an ASTC rating of 47. Other designs may be equally acceptable if their sound resistance can be demonstrated to meet the

minimum ASTC rating or better on the basis of tests referred to in Article 9.11.1.2., or if they comply with Subsection 5.8.1.

However, some caution should be applied when designing solutions that go beyond the options provided in these Tables: for example,

adding more material to a wall could negatively impact its sound performance or have no effect at all.

Table A-9.11.1.4.-A presents compliance options for the construction of separating wall assemblies with flanking floor, ceiling and

wall assemblies in horizontally adjoining spaces.

Table A-9.11.1.4.-A

Options for the Design and Construction of Junctions and Flanking Surfaces Between Separating Wall Assemblies in

Horizontally Adjoining Spaces for Compliance with Clause 9.11.1.1.(1)(b)

Type of Separating

Wall Assembly with

STC ≥ 50 from

Table 9.10.3.1.-A

Options for Design and Construction of Junctions and Flanking Surfaces

(1)

to Address Horizontal Sound Transmission Paths

Bottom Junction (between separating

wall and flanking floors)

Top Junction (between separating wall

and flanking ceiling)

Side Junctions (between separating wall and

flanking walls)

W4, W5, W6

(single stud)

W8, W9, W10,

W11, W12

(staggered studs)

• for additional material layer and

finished flooring, see Table 9.11.1.4.

• subfloor on both sides of wall is

plywood, OSB, waferboard (15.5 mm

thick) or tongue and groove lumber

(≥ 17 mm thick)

• floor is framed with wood joists, wood

I-joists or wood trusses spaced

≥ 400 mm o.c., with or without

absorptive material

(2)

in cavities

• floor joists or trusses are oriented

parallel to separating wall

(non-loadbearing case) or

perpendicular to separating wall but

are not continuous across junction

(loadbearing case)

• ceiling is framed with wood joists,

wood I-joists, or wood trusses, with or

without absorptive material

(2)

in cavities

• ceiling joists or trusses are oriented

perpendicular to separating wall but

are not continuous across junction

(loadbearing case) or parallel to

junction (non-loadbearing case)

• gypsum board ceiling is fastened

directly to bottom of ceiling framing or

on resilient metal channels

(3)

• gypsum board on flanking walls ends or is cut at

separating wall and is fastened directly to

framing or on resilient metal channels

(3)

• flanking wall is framed with single row of wood

studs, staggered studs on a single

38 mm × 140 mm plate, or 2 rows of

38 mm × 89 mm wood studs on separate

38 mm × 89 mm plates, with or without

absorptive material

(2)

in cavities

• flanking wall framing is structurally connected to

separating wall and terminates where it butts

against framing of separating wall or is

continuous across junction

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Example Showing Side View of Bottom and Top Junctions Example Showing Plan View of Side Junctions

Table A-9.11.1.4.-A (continued)

Options for the Design and Construction of Junctions and Flanking Surfaces Between Separating Wall Assemblies in

Horizontally Adjoining Spaces for Compliance with Clause 9.11.1.1.(1)(b)

Type of Separating

Wall Assembly with

STC ≥ 50 from

Table 9.10.3.1.-A

Options for Design and Construction of Junctions and Flanking Surfaces

(1)

to Address Horizontal Sound Transmission Paths

Bottom Junction (between separating

wall and flanking floors)

Top Junction (between separating wall

and flanking ceiling)

Side Junctions (between separating wall and

flanking walls)

EG01399A

ceiling

W5 separating wall

additional material layer

over subfloor plus

finished flooring with

mass per area > 8 kg/m²

EG02084A

W5 separating wall

flanking wall

EG02087A

ceiling

W12 separating wall

additional material

layer over subfloor

plus finished flooring

with mass per area

> 8 kg/m

EG02086A

W12 separating wall

flanking wall

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

W13, W14, W15 • for additional material layer and

finished flooring, see Table 9.11.1.4.

• subfloor on both sides of wall is

plywood, OSB, waferboard (15.5 mm

thick) or tongue and groove lumber

(≥ 17 mm thick)

• floor is framed with wood joists, wood

I-joists or wood trusses spaced

≥ 400 mm o.c., with or without

absorptive material

(2)

in cavities

• floor joists or trusses are oriented

parallel to separating wall

(non-loadbearing case) or

perpendicular to separating wall but

are not continuous across junction

(loadbearing case)

• near leaf of separating wall is

supported on “designated” joist

• wood joists, wood I-joists or wood

trusses are oriented perpendicular or

parallel to separating wall, with or

without absorptive material

(2)

in cavities

• joist framing at junction is supported

on near leaf of separating wall

• gypsum board ceiling panels end at

wall framing and are fastened directly

to bottom of ceiling framing or on

resilient metal channels

(3)

• flanking wall framing is fastened to adjacent leaf

of separating wall

• flanking wall is framed with single row of wood

studs, staggered studs on a single 38 mm ×

140 mm plate, or 2 rows of 38 mm × 89 mm

wood studs on separate 38 mm × 89 mm

plates, with or without absorptive material

(2)

in cavities

• gypsum board panels on flanking walls ends or

is cut at framing of separating wall and is

fastened on resilient metal channels

(3)

directly to framing of flanking wall if that framing

and any sheathing are not continuous across

the junction

Example Showing Side View of Bottom and Top Junctions Example Showing Plan View of Side Junctions

Table A-9.11.1.4.-A (continued)

Options for the Design and Construction of Junctions and Flanking Surfaces Between Separating Wall Assemblies in

Horizontally Adjoining Spaces for Compliance with Clause 9.11.1.1.(1)(b)

Type of Separating

Wall Assembly with

STC ≥ 50 from

Table 9.10.3.1.-A

Options for Design and Construction of Junctions and Flanking Surfaces

(1)

to Address Horizontal Sound Transmission Paths

Bottom Junction (between separating

wall and flanking floors)

Top Junction (between separating wall

and flanking ceiling)

Side Junctions (between separating wall and

flanking walls)

EG01366A

ceiling

W13 separating

wall

additional material

layer over subfloor

plus finished flooring

with mass per area

> 8 kg/m

EG01365A

W13 separating wall

flanking wall

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

S1 to S15 • F1 concrete floor assembly from

Table 9.10.3.1.-B with mass per area

not less than 300 kg/m

(e.g.

normal-weight concrete with average

thickness of 130 mm)

• with or without an additional material

layer or finished flooring

• F1 concrete floor assembly from

Table 9.10.3.1.-B with mass per area

not less than 300 kg/m

(e.g. normal-weight concrete with

average thickness of 130 mm)

• with or without gypsum board ceiling

suspended below concrete floor

• flanking wall framing is structurally connected to

separating wall and terminates where it butts

against framing of separating wall or is

continuous across junction

• gypsum board on flanking walls ends or is cut at

separating wall and is fastened directly to

framing or on resilient metal channels

(3)

• flanking wall consists of steel framing

(loadbearing or non-loadbearing steel studs) or

concrete blocks with mass per area not less

than 200 kg/m

(e.g. normal-weight hollow core

concrete block units

(4)

with a gypsum board

lining supported on framing providing a cavity

not less than 50 mm deep)

• with or without absorptive material

(2)

in cavities

behind gypsum board of flanking walls

Example Showing Side View of Bottom and Top Junctions Example Showing Plan View of Side Junctions

B1 to B10 • same options as stated above for

walls S1 to S15

• same options as stated above for

walls S1 to S15

• junction at top of concrete block

assembly is loadbearing or

non-loadbearing resilient joint

• same options as stated above for walls S1

to S15

Table A-9.11.1.4.-A (continued)

Options for the Design and Construction of Junctions and Flanking Surfaces Between Separating Wall Assemblies in

Horizontally Adjoining Spaces for Compliance with Clause 9.11.1.1.(1)(b)

Type of Separating

Wall Assembly with

STC ≥ 50 from

Table 9.10.3.1.-A

Options for Design and Construction of Junctions and Flanking Surfaces

(1)

to Address Horizontal Sound Transmission Paths

Bottom Junction (between separating

wall and flanking floors)

Top Junction (between separating wall

and flanking ceiling)

Side Junctions (between separating wall and

flanking walls)

EG01368A

concrete floor

S14 separating wall

EG01369A

S14 separating wall

flanking wall

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Table A-9.11.1.4.-B presents options for improving the sound performance of separating wall systems beyond that achieved by

implementing the options presented in Table A-9.11.1.4.-A. The suggested performance improvement options are listed in order of

approximate acoustic priority and are interdependent, i.e., if options at the top of the list are not implemented, then options at the

bottom of the list will have much lesser effect.

Example Showing Side View of Bottom and Top Junctions Examples Showing Plan View of Side Junctions

Notes to Table A-9.11.1.4.-A:

(1) See also Table A-9.11.1.4.-B.

(2) Sound absorptive material is porous (closed-cell foam was not tested) and includes fibre processed from rock, slag, glass or cellulose fibre with a maximum density of

32 kg/m

. See Notes (5) and (8) of Table 9.10.3.1.-A and Note (5) of Table 9.10.3.1.-B for additional information.

(3) Resilient metal channels are formed from steel having a maximum thickness of 0.46 mm (25 gauge) with slits or holes in the single “leg” between the faces fastened to the

framing and to the gypsum board (see Figure A-9.10.3.1.-D). ASTM C 754, “Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel Products,”

describes the installation of resilient metal channels.

(4) Normal-weight concrete block units conforming to CSA A165.1, “Concrete Block Masonry Units,” have aggregate with a density not less than 2 000 kg/m

; 190 mm hollow

core units are 53% solid, providing a wall mass per area over 200 kg/m

; 140 mm hollow core units are 75% solid, providing a wall mass per area over 200 kg/m

Table A-9.11.1.4.-A (continued)

Options for the Design and Construction of Junctions and Flanking Surfaces Between Separating Wall Assemblies in

Horizontally Adjoining Spaces for Compliance with Clause 9.11.1.1.(1)(b)

Type of Separating

Wall Assembly with

STC ≥ 50 from

Table 9.10.3.1.-A

Options for Design and Construction of Junctions and Flanking Surfaces

(1)

to Address Horizontal Sound Transmission Paths

Bottom Junction (between separating

wall and flanking floors)

Top Junction (between separating wall

and flanking ceiling)

Side Junctions (between separating wall and

flanking walls)

EG01370A

B3 separating wall

concrete floor

EG01371A

B3 separating wall

flanking wall

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Table A-9.11.1.4.-B

Options for the Construction of a Separating Wall System to Further Improve the

Sound Insulation Performance Achieved with the Options in Table A-9.11.1.4.-A

Type of Separating Wall

Assembly with STC ≥ 50

from Table 9.10.3.1.-A

Performance Improvement Options for Junctions Between Separating Walls and Flanking Floor/Ceiling Assemblies

W4, W5, W6, W8, W9,

W10, W11, W12

• Increase mass per area of additional material layer and finished flooring over subfloor (e.g. concrete or gypsum concrete

topping)

• Choose separating wall assembly with higher STC rating

• Orient floor and ceiling joists parallel to separating wall (non-loadbearing case)

• Add resilient layer under additional material layer over subfloor or between additional material layer and finished flooring

• Support gypsum board panels of ceiling on resilient metal channels

(1)

• Support gypsum board panels of flanking walls on resilient metal channels

(1)

W13, W14, W15 • If seismic or other structural requirements permit, choose a fire block detail at floor/wall junction in accordance with

Subsection 9.10.16. that does not provide a rigid connection between the two rows of framing of the separating wall

(e.g. subfloor not continuous across junction and semi-rigid fibre insulation board filling the gap in accordance with

Article 9.10.16.3.). In this case, an additional material layer would not be necessary. Also, choose separating wall assembly

with higher STC rating (e.g. more absorptive material

(2)

in cavities and/or more gypsum board).

• If having a rigid structural connection at the floor/wall junction (such as subfloor continuous across the junction) is required

for seismic or other structural reasons, obtain a higher ASTC rating as follows:

• Increase combined mass per area of additional material layer over subfloor and finished flooring (e.g. concrete or gypsum

concrete topping)

• Choose separating wall assembly with higher STC rating (e.g. more absorptive material

(2)

and/or more gypsum board)

• Support gypsum board panels of ceiling on resilient metal channels

(1)

• Support gypsum board panels of flanking walls on resilient metal channels

(1)

• Add resilient layer under additional material layer over subfloor or between additional material layer and finished flooring

S1 to S15 • Choose separating wall assembly with higher STC rating

• Increase thickness of concrete floor slab and/or add material layer and finished flooring over subfloor

• Add gypsum board ceiling on framing supported under the floor above, with cavity not less than 100 mm deep

• Add resilient layer under additional material layer over subfloor or between additional material layer and finished flooring

• Support gypsum board panels of flanking walls on resilient metal channels

(1)

if steel studs are loadbearing type

B1 to B10 • Choose separating wall assembly with higher STC rating

• Add gypsum board ceiling supported below concrete floor with cavity not less than 100 mm deep and sound absorptive

material

(2)

in cavity

• Increase thickness of concrete floor slab and/or add material layer and finished flooring over subfloor

• Add resilient layer under additional material layer over subfloor or between additional material layer and finished flooring and

increase mass per area of additional material layer and finished flooring (e.g. floating concrete or gypsum concrete topping)

• Support gypsum board panels of flanking walls on resilient metal channels

(1)

if steel studs are loadbearing type

Notes to Table A-9.11.1.4.-B:

(1) Resilient metal channels are formed from steel having a maximum thickness of 0.46 mm (25 gauge) with slits or holes in the single “leg” between the faces fastened to the

framing and to the gypsum board (see Figure A-9.10.3.1.-D). ASTM C 754, “Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel Products,”

describes the installation of resilient metal channels.

(2) Sound absorptive material is porous (closed-cell foam was not tested) and includes fibre processed from rock, slag, glass or cellulose fibre with a maximum density of

32 kg/m

. See Notes (5) and (8) of Table 9.10.3.1.-A and Note (5) of Table 9.10.3.1.-B for additional information.

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Table A-9.11.1.4.-C presents compliance options for the construction of separating floor/ceiling assemblies with flanking wall

assemblies in vertically adjoining spaces.

Table A-9.11.1.4.-C

Options for the Design and Construction of Junctions and Flanking Surfaces Between Separating Floor/Ceiling

Assemblies in Vertically Adjoining Spaces for Compliance with Clause 9.11.1.1.(1)(b)

Type of Separating

Floor/Ceiling Assembly with

STC ≥ 50 from

Table 9.10.3.1.-B

Options for Design and Construction of Junctions and Flanking Surfaces

(1)

to Address Vertical Sound Transmission Paths

Junctions with Flanking Steel-Framed Walls Junctions with Flanking Concrete Walls

F1 (with or without gypsum

board ceiling)

• floor ends at flanking wall assembly (T-junction) or extends

beyond it (cross-junction)

• steel framing of flanking walls is loadbearing or

non-loadbearing, with a single row of steel studs, staggered

studs, or 2 rows of studs, with studs spaced not less than

400 mm o.c., with or without absorptive material

(2)

in cavities

• flanking wall structure is fastened to separating concrete

floor but is not continuous across junction

• gypsum board on flanking walls is not continuous across

junction and is fastened directly to wall framing or on

resilient metal channels

(3)

• floor ends at flanking wall assembly (T-junction) or extends

beyond it (cross-junction)

• one wythe of concrete blocks with mass per area not less

than 200 kg/m

(e.g. normal-weight hollow core concrete

block units

(4)

)

• loadbearing (solid) or non-loadbearing (resilient) junction

between top of flanking concrete block wall and floor

structure

• gypsum board lining is supported on wood or steel framing

providing a cavity not less than 50 mm deep, with or without

absorptive material

(2)

in cavities

• gypsum board on flanking walls is not continuous across

junction and is fastened directly to wall framing or on

resilient metal channels

(3)

Examples Showing Side View of Junctions

F8 to F38 Junctions with Flanking Loadbearing or Non-Loadbearing Walls

• wood studs of flanking wall are 38 mm × 89 mm or 38 mm × 140 mm and spaced 400 mm or 600 mm o.c.

• flanking wall framing consists of single row of wood studs, staggered studs on a single 38 mm × 140 mm plate, or 2 rows of

38 mm × 89 mm wood studs on separate 38 mm × 89 mm plates, with or without absorptive material

(2)

in wall cavities

• gypsum board on flanking walls ends or is cut near floor framing and is fastened directly to wall framing or supported on

resilient metal channels

(3)

Example Showing Side View of Junctions in Flanking

Loadbearing Wall

Example Showing Side View of Junctions in Flanking

Non-Loadbearing Wall

EG01372A

S14 wall

F1 separating floor

EG01373A

F1 separating floor

B3 wall

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Table A-9.11.1.4.-D presents options for improving the sound performance of separating floor/ceiling assemblies beyond that

achieved by implementing the options presented in Table A-9.11.1.4.-C. The suggested performance improvement options are listed

in order of approximate acoustic priority and are interdependent, i.e., if options at the top of the list are not implemented, then

options at the bottom of the list will have much lesser effect.

Notes to Table A-9.11.1.4.-C:

(1) See also Table A-9.11.1.4.-D.

(2) Sound absorptive material is porous (closed-cell foam was not tested) and includes fibre processed from rock, slag, glass or cellulose fibre with a maximum density of

32 kg/m

. See Notes (5) and (8) of Table 9.10.3.1.-A and Note (5) of Table 9.10.3.1.-B for additional information.

(3) Resilient metal channels are formed from steel having a maximum thickness of 0.46 mm (25 gauge) with slits or holes in the single “leg” between the faces fastened to the

framing and to the gypsum board (see Figure A-9.10.3.1.-D). ASTM C 754, “Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel Products,”

describes the installation of resilient metal channels.

(4) Normal-weight concrete block units conforming to CSA A165.1, “Concrete Block Masonry Units,” have aggregate with a density not less than 2000 kg/m

; 190 mm hollow

core units are 53% solid, providing a wall mass per area over 200 kg/m

; 140 mm hollow core units are 75% solid, providing a wall mass per area over 200 kg/m

Table A-9.11.1.4.-C (continued)

Options for the Design and Construction of Junctions and Flanking Surfaces Between Separating Floor/Ceiling

Assemblies in Vertically Adjoining Spaces for Compliance with Clause 9.11.1.1.(1)(b)

Type of Separating

Floor/Ceiling Assembly with

STC ≥ 50 from

Table 9.10.3.1.-B

Options for Design and Construction of Junctions and Flanking Surfaces

(1)

to Address Vertical Sound Transmission Paths

EG01374A

F8d separating floor

EG01375A

F8d separating floor

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-Table 9.11.1.4. Floor Treatments. The sound insulation performance of lightweight framed floors can be improved by

adding floor treatments, i.e., additional layers of material over the subfloor (e.g. concrete topping, OSB or plywood) and finished

flooring or coverings (e.g., carpet, engineered wood). Table A-Table 9.11.1.4. presents the mass per area values based on thickness and

density of a number of generic floor treatment materials (the values for proprietary products may be different; consult the

manufacturer’s current data sheets for their products’ values).

Table A-9.11.1.4.-D

Options for the Construction of a Separating Floor System to Further Improve the Sound Insulation Performance

Achieved with the Options in Table A-9.11.1.4.C.

Type of Separating Floor

Assembly with STC ≥ 50

from Table 9.10.3.1.-B

Performance Improvement Options for Junctions Between Separating Floors and Flanking Wall Assemblies

F1 (with or without gypsum

board ceiling)

• Add heavier additional material layer over subfloor and/or resilient layer under additional material layer or between additional

material layer and finished flooring

• Add gypsum board ceiling supported at least 100 mm below concrete floor with minimal structural connection (e.g. ceiling

framing supported resiliently) and sound absorptive material

(1)

in cavity

• Support gypsum board of flanking walls of lower room on resilient metal channels

(2)

(if framed with loadbearing studs)

F8 to F38 • Add heavier additional material layer over subfloor and/or resilient layer under additional material layer or between additional

material layer and finished flooring

• Add more/heavier gypsum board to ceiling and increase spacing of resilient metal channels

(2)

to 600 mm o.c.

• Support gypsum board of flanking loadbearing walls of lower room on resilient metal channels

(2)

• Support gypsum board on flanking non-loadbearing walls of lower room on resilient metal channels

(2)

Notes to Table A-9.11.1.4.-D:

(1) Sound absorptive material is porous (closed-cell foam was not tested) and includes fibre processed from rock, slag, glass or cellulose fibre with a maximum density of

32 kg/m

. See Notes (5) and (8) of Table 9.10.3.1.-A and Note (5) of Table 9.10.3.1.-B for additional information.

(2) Resilient metal channels are formed from steel having a maximum thickness of 0.46 mm (25 gauge) with slits or holes in the single “leg” between the faces fastened to the

framing and to the gypsum board (see Figure A-9.10.3.1.-D). ASTM C 754, “Installation of Steel Framing Members to Receive Screw-Attached Gypsum Panel Products,”

describes the installation of resilient metal channels.

Table A-9.11.1.4.

Mass per Area of Floor Treatment Materials

Floor Treatment Material Thickness, mm Density, kg/m³ Mass per Area, kg/m

Materials Typically Having a Mass per Area Less Than 8 kg/m

Medium-density fibreboard (MDF) 2.9–6.1 790-–810 2.3–5.0

Plywood – generic softwood 12.5–13.3 450–500 5.6–6.6

15.5–16.3 7.0–8.1

Ceramic tile 8.4 700–1 000 5.9–8.4

Materials Typically Having a Mass per Area Greater Than 8 kg/m

but Less Than 16 kg/m

Particleboard 11.3–19.2 710–755 8.1–14.5

Medium-density fibreboard (MDF) 13.9–21.1 640–755 8.9–15.9

Oriented strandboard (OSB) 14.3–15.8 600–680 8.6–10.7

17.3–18.8 10.4–12.8

Plywood – generic softwood 25.5 450–500 11.5–13.1

Materials Typically Having a Mass per Area Greater Than 16 kg/m² but Less Than 32 kg/m

Medium-density fibreboard (MDF) 25.0–32.1 640–740 16.0–23.7

Materials Typically Having a Mass per Area Greater Than 32 kg/m

Concrete 40.0–50.0 2 015–2 380 80.6–119.0

Gypsum concrete 25.0 1 840–1 870 46.1–46.7

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-Table 9.12.2.2. Minimum Depths of Foundations. The requirements for clay soils or soils not clearly defined are

intended to apply to those soils that are subject to significant volume changes with changes in moisture content.

A-9.12.2.2.(2) Depth and Insulation of Foundations.

Figure A-9.12.2.2.(2)

Foundation insulation and heat flow to footings

A-9.12.3.3.(1) Deleterious Material in Backfill. The deleterious debris referred to in this provision includes, but is not

limited to:

• organic material and other material subject to decomposition and compaction, which could have an adverse effect on grading

around the building,

• materials that will off-gas and have the potential to pose a health hazard, and

• materials that are incompatible with materials used in the foundations, footings, drainage materials or components, or other

elements of the building whose required performance would be adversely affected.

A-9.13.2.5. Protection of Interior Finishes against Moisture. Excess water from cast-in-place concrete and ground

moisture tends to migrate toward interior spaces, particularly in the spring and summer. Where moisture-susceptible materials, such as

finishes or wood members, are in contact with the foundation wall, the moisture needs to be controlled by installing a moisture barrier

on the interior surface of the foundation wall that extends from the underside of the interior finish up the face of the wall to a point

just above the level of the ground outside.

EC00381A

heat flow

Insulated in a manner that will reduce

heat flow to the soil beneath the footings

(b)

heat flow

Insulated in a manner allowing heat flow

to the soil beneath the footings

(a)

heat flow

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

The reason the moisture barrier on the interior surface of the foundation wall must be stopped near ground level is to allow any

moisture that finds its way into the finished wall cavity from the interior space (through leaks in the air or vapour barrier) to diffuse to

the exterior. If the vapour permeance of dampproofing membranes or coatings exceeds 170 ng/(Pa·s·m

), such moisture barriers may

be carried full height; if their vapour permeance is less than that, this moisture risks being trapped on the interior surface of the

moisture barriers. The permeance limit corresponds to the lower limit for breather-type membranes, such as asphalt-impregnated

sheathing paper.

Some insulation products can also be used to protect interior finishes from the effects of moisture. They have shown acceptable

performance when applied over the entire foundation wall because, in this case, they also provide vapour barrier and moisture barrier

functions and possibly also the air barrier function. Where a single product provides all these functions, there is no risk of trapping

moisture between two functional barriers with low water vapour permeance.

A-9.13.4. Soil Gas Control. Outdoor air entering a dwelling through above-grade leaks in the building envelope normally

improves the indoor air quality in the dwelling by reducing the concentrations of pollutants and water vapour. It is only undesirable

because it cannot be controlled. On the other hand, air entering a dwelling through below-grade leaks in the envelope may increase the

water vapour content of the indoor air and may also bring in a number of pollutants picked up from the soil. This mixture of air, water

vapour and pollutants is sometimes referred to as “soil gas.” One pollutant often found in soil gas is radon.

Sentence 9.13.4.2.(1), which requires the installation of an air barrier system, addresses the protection from all soil gases, while the

remainder of Article 9.13.4.2. along with Article 9.13.4.3., which require the provision of the means to depressurize the space between

the air barrier system and the ground, specifically address the capability to mitigate high radon concentrations in the future, should

this become necessary.

Radon is a colourless, odourless, radioactive gas that occurs naturally as a result of the decay of radium. It is found to varying degrees as

a component of soil gas in all regions of Canada and is known to enter dwelling units by infiltration into basements and crawl spaces.

The presence of radon in sufficient quantity can lead to an increased risk of lung cancer.

The potential for high levels of radon infiltration is very difficult to evaluate prior to construction and thus a radon problem may only

become apparent once the building is completed and occupied. Therefore various sections of Part 9 require the application of certain

radon exclusion measures in all dwellings. These measures are

• low in cost,

• difficult to retrofit, and

• desirable for other benefits they provide.

The principal method of resisting the ingress of all soil gases, a resistance which is required for all buildings (see Sentence 9.13.4.2.(1)),

is to seal the interface between the soil and the occupied space, so far as is reasonably practicable. Sections 9.18. and 9.25. contain

requirements for air and soil gas barriers in assemblies in contact with ground, including those in crawl spaces. Providing control joints

to reduce cracking of foundation walls and airtight covers for sump pits (see Section 9.14.) are other measures that can help achieve

this objective. The requirements provided in Subsection 9.25.3. are explained in Notes A-9.25.3.4. and 9.25.3.6. and A-9.25.3.6.(2)

and (3).

The principal method of excluding radon is to ensure that the pressure difference across the ground/space interface is positive

(i.e., towards the outside) so that the inward flow of radon through any remaining leaks will be minimized. The requirements provided

in Article 9.13.4.3. are explained in Note A-9.13.4.3.

A-9.13.4.2.(3) Exception for Buildings Occupied for a Few Hours a Day. The criterion used by Health Canada to

establish the guideline for acceptable radon concentration is the time that occupants spend inside buildings. Health Canada

recommends installing a means for the future removal of radon in b

uildings that are occupied by persons for more than 4 hours

per day. Sentence 9.13.4.2.(3) therefore does not apply to buildings or portions of buildings that are intended to be occupied for less

than 4 hours a day. Addressing a radon problem in such buildings in the future, should that become necessary, can also be achieved by

providing a means for increased ventilation at times when these buildings are occupied.

A-9.13.4.3.

Providing Performance Criteria for the Depressurization of the Space Between the Air Barrier System and

the Ground

Article 9.13.4.3. contains two sets of requirements: Sentence (2) describes the criteria for subfloor depressurization systems using

performance-oriented language, while Sentence (3) describes one particular acceptable solution using more prescriptive language.

In some cases, subfloor depressurization requires a solution other than the one described in Sentence (3), for example, where

compactable fill is installed under slab-on-grade construction.

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Completion of a Subfloor Depressurization System

The completion of a subfloor depressurization system may be necessary to reduce the radon concentration to a level below the

guideline specified by Health Canada. In this case, to complete the system, the radon vent pipe is mechanically assisted to enable

effective depressurization of the space between the air barrier system and the ground. An electrically powered fan is typically

installed somewhere along the radon vent pipe.

Further information on protection from radon ingress can be found in the following Health Canada publications:

• “Radon: A Guide for Canadian Homeowners” (CMHC/HC), and

• “Guide for Radon Measurements in Residential Dwellings (Homes).”

A-9.13.4.3. Vent Terminals. To prevent soil gases from entering a building through air intakes, windows, and other openings

in the building envelope, radon vent pipe terminations should be installed in a similar manner to plumbing vent terminals.

(See A-2.5.6.5.(4) in Appendix A of Division B to Book II of the Code.)

A-9.13.4.3.(2)(b)(i) and (3)(b)(i) Effective Depressurization. To allow effective depressurization of the space between

the air barrier system and the ground, the extraction opening (the pipe) should not be blocked and should be arranged such that air

can be extracted from the entire space between the air barrier system and the ground. This will ensure that the extraction system can

maintain negative pressure underneath the entire floor (or in heated crawl spaces underneath the air barrier system). The arrangement

and location of the extraction system inlet(s) may have design implications where the footing layout separates part of the space

underneath the floor.

A-9.14.2.1.(2)(a) Insulation Applied to the Exterior of Foundation Walls. In addition to the prevention of heat loss,

some types of mineral fibre insulation, such as rigid glass fibre, are installed on the exterior of basement walls for the purpose of

moisture control. This is sometimes used instead of crushed rock as a drainage layer between the basement wall and the surrounding

soil in order to facilitate the drainage of soil moisture. Water drained by this drainage layer must be carried away from the foundation

by the footing drains or the granular drainage layer in order to prevent it from developing hydro-static pressure against the wall.

Provision must be made to permit the drainage of this water either by extending the insulation or crushed rock to the drain or by the

installation of granular material connecting the two. The installation of such drainage layer does not eliminate the need for normal

waterproofing or dampproofing of walls as specified in Section 9.13.

A-9.15.1.1. Application of Footing and Foundation Requirements to Decks and Similar

Constructions. Because decks, balconies, verandas and similar platforms support occupancies, they are, by definition, considered

as buildings or parts of buildings. Consequently, the requirements in Section 9.15. regarding footings and foundations apply to these

constructions.

A-9.15.1.1.(1)(c) and 9.20.1.1.(1)(b) Flat Insulating Concrete Form Walls. Insulating concrete form (ICF) walls are

concrete walls that are cast into polystyrene forms, which remain in place after the concrete has cured. Flat ICF walls are solid ICF

walls where the concrete is of uniform thickness over the height and width of the wall.

A-9.15.2.4.(1) Preserved Wood Foundations – Design Assumptions. Tabular data and figures in CSA S406,

“Permanent Wood Foundations for Housing and Small Buildings,” are based upon the general principles provided in CSA O86,

“Engineering Design in Wood,” with the following assumptions:

•

soil bearing capacity: 75 kPa or more,

• clear spans for floors: 5 000 mm or less,

• floor loadings: 1.9 kPa for first floor and suspended floor, and 1.4 kPa for second storey floor,

• foundation wall heights: 2 400 mm for slab floor, 3 000 mm for suspended wood floor,

• top of granular layer to top of suspended wood floor: 600 mm,

• lateral load from soil pressure: equivalent to fluid pressure of 4.7 kPa per metre of depth,

• ground snow load: 3 kPa,

• basic snow load coefficient: 0.6,

• roof loads are carried to the exterior wall,

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

•dead loads:

A-9.15.3.4.(2) Footing Sizes. The footing sizes in Table 9.15.3.4. are based on typical construction consisting of a roof,

not more than 3 storeys, and centre bearing walls or beams. For this reason, Clause 9.15.3.3.(1)(b) stipulates a maximum supported

joist span of 4.9 m.

It has become common to use flat wood trusses or wood I-joists to span greater distances in floors of small buildings. Where these

spans exceed 4.9 m, minimum footing sizes may be based on the following method:

(a) Determine for each storey the span of joists that will be supported on a given footing. Sum these lengths (sum

(b) Determine the product of the number of storeys times 4.9 m (sum

to sum

(d) Multiply this ratio by the minimum footing sizes in Table 9.15.3.4. to get the required minimum footing size.

Example: A 2-storey house is built using wood I-joists spanning 6 m.

(a) sum

= 6 + 6 = 12 m

(b) sum

= 4.9 × 2 = 9.8 m

/sum

= 12/9.8 = 1.22

(d) required minimum footing size = 1.22 × 350 mm (minimum footing size provided in Table 9.15.3.4.) = 427 mm.

A-9.16.2.1.(1) Drainage Layer Beneath Floors-on-Ground. A drainage layer required by Sentence 9.16.2.1.(1) shall also

be gas-permeable and conform to Article 9.13.4.3. in buildings to which that Article applies.

A-9.17.2.2.(2) Lateral Support of Columns. Because the Code does not provide prescriptive criteria to describe the

minimum required lateral support, constructions are limited to those that have demonstrated effective performance over time and

those that are designed according to Part 4. Verandas on early 20th century homes provide one example of constructions whose floor

and roof are typically tied to the rest of the building to provide effective lateral support. Large decks set on tall columns, however,

are likely to require additional lateral support even where they are connected to the building on one side.

A-9.17.3.4. Design of Steel Columns. The permitted live floor loads of 2.4 kPa and the spans described for steel beams,

wood beams and floor joists are such that the load on columns could exceed 36 kN, the maximum allowable load on columns

prescribed in CAN/CGSB-7.2, “Adjustable Steel Columns.” In the context of Part 9, loads on columns are calculated from the

supported area times the live load per unit area, using the supported length of joists and beams. The supported length is half of the

joist spans on each side of the beam and half the beam span on each side of the column.

Dead load is not included based on the assumption that the maximum live load will not be applied over the whole floor. Designs

according to Part 4 must consider all applied loads.

A-9.18.7.1.(4) Protection of Ground Cover in Warm Air Plenums. The purpose of the requirement is to protect

combustible ground cover from smouldering cigarette butts that may drop through air registers. The protective material should extend

beyond the opening of the register and have up-turned edges, as a butt may be deflected sideways as it falls.

A-9.19.1.1.(1) Venting of Attic or Roof Spaces. Controlling the flow of moisture by air leakage and vapour diffusion into

attic or roof spaces is necessary to limit moisture-induced deterioration. Given that imperfections normally exist in the vapour barriers

and air barrier systems, recent research indicates that venting of attic or roof spaces is generally still required. The exception provided

in Article 9.19.1.1. recognizes that some specialized ceiling-roof assemblies, such as those used in some factory-built buildings, have,

over time, demonstrated that their construction is sufficiently tight to prevent excessive moisture accumulation. In these cases,

ventilation would not be required.

roof 0.50 kPa

floor 0.47 kPa

wall (with siding) 0.32 kPa

wall (with masonry veneer) 1.94 kPa

foundation wall 0.27 kPa

partitions 0.20 kPa

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.19.2.1.(1) Access to Attic or Roof Space. The term “open space” refers to the space between the insulation and the

roof sheathing. Sentence 9.19.2.1.(1) requires the installation of an access hatch where the open space in the attic or roof is large

enough to allow visual inspection. Although the dimensions of an uninsulated attic or roof space may meet the size that triggers the

requirement for an access hatch to be installed, most of that space will actually be filled with insulation and may therefore not be easily

inspected, particularly in smaller buildings or under low-sloped roofs. See also Article 9.36.2.6.

A-9.20.1.2. Seismic Information. Information on spectral response acceleration values for various locations can be found in

Appendix C.

A-9.20.5.1.(1) Masonry Support. Masonry veneer must be supported on a stable structure in order to avoid cracking of the

masonry due to differential movement relative to parts of the support. Wood framing is not normally used as a support for the weight

of masonry veneer because of its shrinkage characteristics. Where the weight of masonry veneer is supported on a wood structure, as is

the case for the preserved wood foundations referred to in Sentence 9.20.5.1.(1) for example, measures must be taken to ensure that

any differential movement that may be harmful to the performance of masonry is minimized or accommodated. The general principle

stated in Article 9.4.1.1., however, makes it possible to support the weight of masonry veneer on wood framing, provided that

engineering design principles prescribed in Part 4 are followed to ensure that the rigidity of the support is compatible with the stiffness

of the masonry being supported and that differential movements between the support and masonry are accommodated.

A-9.20.8.5.(1) Projection of Masonry Beyond Supporting Members.

Figure A-9.20.8.5.(1)

Maximum projection of masonry veneer beyond its support

EG00573E

solid

masonry

units

projection of masonry

veneer ≤ 1/3 of its thickness

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.20.12.2.(2) Corbelling of Masonry Foundation Walls.

Figure A-9.20.12.2.(2)

Maximum corbel dimensions

A-9.20.13.9.(3) Dampproofing of Masonry Walls. The reason for installing a sheathing membrane behind masonry walls

is to prevent rainwater from reaching the interior finish if it should leak past the masonry. The sheathing membrane intercepts the

rainwater and leads it to the bottom of the wall where the flashing directs it to the exterior via weep holes. If the insulation is a type

that effectively resists the penetration of water, and is installed so that water will not collect behind it, then there is no need for a

sheathing membrane. If water that runs down between the masonry and the insulation is able to leak out at the joints in the insulation,

such insulation will not act as a substitute for a sheathing membrane. If water cannot leak through the joints in the insulation but

collects in cavities between the masonry and insulation, subsequent freezing could damage the wall. Where a sheathing membrane is

not used, the adhesive or mortar should therefore be applied to form a continuous bond between the masonry and the insulation.

If this is not practicable because of an irregular masonry surface, then a sheathing membrane is necessary.

A-9.21.3.6.(2) Metal Chimney Liners. Under the provisions of Article 1.2.1.1. of Division A, masonry chimneys with metal

liners may be permitted to serve solid-fuel-burning appliances if tests show that such liners will provide an equivalent level of safety.

inner face of

cavity wall

EG00450B

brick

≤ h/2 and ≤ t

brick

≤ t

foundation

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.21.4.4.(1) Location of Chimney Top.

Figure A-9.21.4.4.(1)

Vertical and horizontal distances from chimney top to roof

A-9.21.4.5.(2) Lateral Support for Chimneys. Where a chimney is fastened to the house framing with metal anchors,

in accordance with CSA A370, “Connectors for Masonry,” it is considered to have adequate lateral support. The portion of the

chimney stack above the roof is considered as free standing and may require additional lateral support.

A-9.21.5.1.(1) Clearance from Combustible Materials. For purposes of this Sentence, an exterior chimney can be

considered to be one which has at least one surface exposed to the outside atmosphere or unheated space over the majority of its

height. All other chimneys should be considered to be interior.

A-9.23.1.1. Constructions Other than Light Wood-Frame Constructions. The prescriptive requirements in

Section 9.23. apply only to standard light wood-frame construction. Other constructions, such as post, beam and plank construction,

plank frame wall construction, and log construction must be designed in accordance with Part 4.

A-9.23.1.1.(1) Application of Section 9.23. In previous editions of the Code, Sentence 9.23.1.1.(1) referred to

“conventional” wood-frame construction. Over time, conventions have changed and the application of Part 9 has expanded.

The prescriptive requirements provided in Section 9.23. still focus on lumber beams, joists, studs and rafters as the main structural

elements of “wood-frame construction.” The requirements recognize – and have recognized for some time – that walls and floors may

be supported by components made of material other than lumber; for example, by foundations described in Section 9.15. or by steel

beams described in Article 9.23.4.3. These constructions still fall within the general category of wood-frame construction.

With more recent innovations, alternative structural components are being incorporated into wood-frame buildings. Wood I-joists,

for example, are very common. Where these components are used in lieu of lumber, the requirements in Section 9.23. that specifically

apply to lumber joists do not apply to these components: for example, limits on spans and acceptable locations for notches and holes.

However, requirements regarding the fastening of floor sheathing to floor joists still apply, and the use of wood I-joists does not affect

the requirements for wall or roof framing.

Similarly, if steel floor joists are used in lieu of lumber joists, the requirements regarding wall or roof framing are not affected.

Conversely, Sentence 9.23.1.1.(1) precludes the installation of precast concrete floors on wood-frame walls since these are not

“generally comprised of … small repetitive structural members … spaced not more than 600 mm o.c.”

900 mm min.

600 mm min.

less than 3 m

600 mm min.

3 m

EG00457B

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Thus, the reference to “engineered components” in Sentence 9.23.1.1.(1) is intended to indicate that, where an engineered product is

used in lieu of lumber for one part of the building, this does not preclude the application of the remainder of Section 9.23. to the

structure, provided the limits to application with respect to cladding, sheathing or bracing, spacing of framing members, supported

loads and maximum spans are respected.

A-9.23.3.1.(2) Alternative Nail Sizes. Where power nails or nails with smaller diameters than that required by

Table 9.23.3.4. are used to connect framing, the following equations can be used to determine the required spacing or required

number of nails.

The maximum spacing can be reduced using the following equation:

where

adj = adjusted nail spacing ≥ 20 × nail diameter,

table = nail spacing required by Table 9.23.3.4.,

red = smaller nail diameter than that required by Table 9.23.3.1., and

table = nail diameter required by Table 9.23.3.1.

The number of nails can be increased using the following equation:

where

adj = adjusted number of nails,

table = number of nails required by Table 9.23.3.4.,

table = nail diameter required by Table 9.23.3.1., and

red = smaller nail diameter than required by Table 9.23.3.1.

Note that nails should be spaced sufficiently far apart – preferably no less than 55 mm apart – to avoid splitting of framing lumber.

A-9.23.3.1.(3) Standard for Screws. The requirement that wood screws conform to ASME B18.6.1, “Wood Screws

(Inch Series),” is not intended to preclude the use of Robertson head screws. The requirement is intended to specify the mechanical

properties of the fastener, not to restrict the means of driving the fastener.

A-9.23.3.3.(1) Prevention of Splitting. Figure A-9.23.3.3.(1) illustrates the intent of the phrase “staggering the nails in the

direction of the grain.”

Figure A-9.23.3.3.(1)

Staggered nailing

A-Table 9.23.3.5.-B Alternative Nail Sizes. Where power nails or nails having a different diameter than the diameters listed

in CSA B111, “Wire Nails, Spikes and Staples,” are used to connect the edges of the wall sheathing to the wall framing of

wood-sheathed braced wall panels, the maximum spacing should be as shown in Table A-Table 9.23.3.5.-B.

direction of grain

staggered nailing

EG01218A

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.23.4.2. Span Tables for Wood Joists, Rafters and Beams. In these span tables the term “rafter” refers to a sloping

wood framing member which supports the roof sheathing and encloses an attic space but does not support a ceiling. The term “roof

joist” refers to a horizontal or sloping wood framing member that supports the roof sheathing and the ceiling finish but does not

enclose an attic space.

Where rafters or roof joists are intended for use in a locality having a higher specified roof snow load than shown in the tables,

the maximum member spacing may be calculated as the product of the member spacing and specified snow load shown in the span

tables divided by the specified snow load for the locality being considered. The following examples show how this principle can be

applied:

(a) For a 3.5 kPa specified snow load, use spans for 2.5 kPa and 600 mm o.c. spacing but space members 400 mm o.c.

(b) For a 4.0 kPa specified snow load, use spans for 2.0 kPa and 600 mm o.c. spacing but space members 300 mm o.c.

The maximum spans in the span tables are measured from the inside face or edge of support to the inside face or edge of support.

In the case of sloping roof framing members, the spans are expressed in terms of the horizontal distance between supports rather than

the length of the sloping member. The snow loads are also expressed in terms of the horizontal projection of the sloping roof. Spans for

odd size lumber may be estimated by straight line interpolation in the tables.

These span tables may be used where members support a uniform live load only. Where the members are required to be designed to

support a concentrated load, they must be designed in conformance with Subsection 4.3.1.

Supported joist length in Span Tables 9.23.4.2.-H, 9.23.4.2.-I and 9.23.4.2.-J means half the sum of the joist spans on both sides of

the beam. For supported joist lengths between those shown in the tables, straight line interpolation may be used in determining the

maximum beam span.

Span Tables 9.23.4.2.-A to 9.23.12.3.-D cover only the most common configurations. Especially in the area of floors, a wide variety of

other configurations is possible: glued subfloors, concrete toppings, machine stress rated lumber, etc. The Canadian Wood Council

publishes “The Span Book,” a compilation of span tables covering many of these alternative configurations. Although these tables have

not been subject to the formal committee review process, the Canadian Wood Council generates, for the CCBFC, all of the Code’s

span tables for wood structural components; thus Code users can be confident that the alternative span tables in “The Span Book”

are consistent with the span tables in the Code and with relevant Code requirements.

Spans for wood joists, rafters and beams which fall outside the scope of these tables, including those for U.S. species and individual

species not marketed in the commercial species combinations described in the span tables, can be calculated in conformance with

CSA O86, “Engineering Design in Wood.”

A-9.23.4.2.(2) Numerical Method to Establish Vibration-Controlled Spans for Wood-Frame Floors.

In addition to the normal strength and deflection analyses, the calculations on which the floor joist span tables are based include a

method of ensuring that the spans are not so long that floor vibrations could lead to occupants perceiving the floors as too “bouncy” or

“springy.” Limiting deflection under the normal uniformly distributed loads to 1/360 of the span does not provide this assurance.

Normally, vibration analysis requires detailed dynamic modelling. However, the calculations for the span tables use the following

simplified static analysis method of estimating vibration-acceptable spans:

• The span which will result in a 2 mm deflection of a single joist

supporting a 1 kN concentrated midpoint load is calculated.

• This span is multiplied by a factor, K, to determine the “vibration-controlled” span for the entire floor system. If this span is less

than the strength- or deflection-controlled span under uniformly distributed load, the vibration-controlled span becomes the

maximum span.

Table A-Table 9.23.3.5.-B

Alternative Nail Diameters and Spacing

Element Nail Diameter, mm

(1)

Maximum Spacing of Nails Along Edges of

Wall Sheathing, mm o.c.

Plywood, OSB or waferboard 2.19-2.52 75

2.53-2.82 100

2.83-3.09 125

> 3.09 150

Notes to Table A-Table 9.23.3.5.-B:

(1) For alternative nail lengths of 63 mm or longer.

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

• The K factor is determined from the following relationship:

where

A, B = constants, the values of which are determined from Tables A-9.23.4.2.(2)-A or A-9.23.4.2.(2)-B,

G = constant, the value of which is determined from Table A-9.23.4.2.(2)-C,

i = span which results in a 2 mm deflection of the joist in question under a 1 kN concentrated midpoint load,

184 = span which results in a 2 mm deflection of a 38 × 184 mm joist of same species and grade as the joist in question

under a 1 kN concentrated midpoint load.

For a given joist species and grade, the value of K shall not be greater than K

, the value which results in a vibration-controlled span of

exactly 3 m. This means that for vibration-controlled spans 3 m or less, K always equals K

, and for vibration-controlled spans greater

than 3 m, K is as calculated.

Note that, for a sawn lumber joist, the ratio S

184

is equivalent to its depth (mm) divided by 184.

Due to rounding differences, the method, as presented here, might produce results slightly different from those produced by the

computer program used to generate the span tables.

Table A-9.23.4.2.(2)-A

Constants A and B for Calculating Vibration-Controlled Floor Joist Spans – General Cases

Forming Part of Note A-9.23.4.2.(2)

Subfloor

Thickness, mm

With Strapping

(1)

With Bridging With Strapping and Bridging

Joist Spacing, mm Joist Spacing, mm Joist Spacing, mm

300 400 600 300 400 600 300 400 600

Constant A

15.5 0.30 0.25 0.20 0.37 0.31 0.25 0.42 0.35 0.28

19.0 0.36 0.30 0.24 0.45 0.37 0.30 0.50 0.42 0.33

Constant B

0.33 0.38 0.41

Notes to Table A-9.23.4.2.(2)-A:

(1) Gypsum board attached directly to joists can be considered equivalent to strapping.

Table A-9.23.4.2.(2)-B

Constants A and B for Calculating Vibration-Controlled Floor Joist Spans – Special Cases

Forming Part of Note A-9.23.4.2.(2)

Subfloor

Thickness, mm

Joists with Ceiling Attached to Wood Furring

(1)

Joists with Concrete Topping

(2)

Without Bridging With Bridging With or Without Bridging

Joist Spacing, mm Joist Spacing, mm Joist Spacing, mm

300 400 600 300 400 600 300 400 600

Constant A

15.5 0.39 0.33 0.24 0.49 0.44 0.38 0.58 0.51 0.41

19.0 0.42 0.36 0.27 0.51 0.46 0.40 0.62 0.56 0.47

Constant B

0.34 0.37 0.35

Notes to Table A-9.23.4.2.(2)-B:

(1) Wood furring means 19 × 89 mm boards not more than 600

mm o.c., or 19 × 64 mm boards not more than 300 mm o.c. For all other cases, see Table A-9.23.4.2.(2)-A.

(2) 30 mm to 51 mm normal weight concrete (not less than 20 MPa) placed directly on the subflooring.

ln (K) ⫽ A – B•ln(S

184

) ⫹ G

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Additional background information on this method can be found in the following publications:

• Onysko, D.M. “Deflection Serviceability Criteria for Residential Floors.” Project 43-10C-024. Forintek Canada Corp., Ottawa,

Canada 1988.

• Onysko, D.M. “Performance and Acceptability of Wood Floors – Forintek Studies.” Proceedings of Symposium/Workshop on

Serviceability of Buildings, Ottawa, May 16-18, National Research Council of Canada, Ottawa, 1988.

A-9.23.4.3.(1) Maximum Spans for Steel Beams Supporting Floors in Dwellings. A beam may be considered to be

laterally supported if wood joists bear on its top flange at intervals of 600 mm or less over its entire length, if all the load being applied

to this beam is transmitted through the joists and if 19 mm by 38 mm wood strips in contact with the top flange are nailed on both

sides of the beam to the bottom of the joists supported. Other additional methods of positive lateral support are acceptable.

For supported joist lengths intermediate between those in the table, straight line interpolation may be used in determining the

maximum beam span.

A-Table 9.23.4.3. Spans for Steel Beams. The spans provided in Table 9.23.4.3. reflect a balance of engineering and

acceptable proven performance. The spans have been calculated based on the following assumptions:

• simply supported beam spans

• laterally supported top flange

• yield strength 350 MPa

• deflection limit L/360

• live load: first floor = 1.9 kPa; second floor = 1.4 kPa

• dead load: 1.5 kPa (0.5 kPa floor + 1.0 kPa partition)

The calculation used to establish the specified maximum beam spans also applies a revised live load reduction factor to account for the

lower probability of a full live load being applied over the supported area in Part 9 buildings.

A-9.23.4.4. Concrete Topping. Vibration-controlled spans given in Span Table 9.23.4.2.-B for concrete topping are based on

a partial composite action between the concrete, subflooring and joists. Normal weight concrete having a compressive strength of

not less than 20 MPa, placed directly on the subflooring, provides extra stiffness and results in increased capacity. The use of a bond

breaker between the topping and the subflooring, or the use of lightweight concrete topping limits the composite effects.

Where either a bond breaker or lightweight topping is used, Span Table 9.23.4.2.-A may be used but the additional dead load imposed

by the concrete must be considered. The addition of 51 mm of concrete topping can impose an added load of 0.8 to 1.2 kPa,

depending on the density of the concrete.

Table A-9.23.4.2.(2)-C

Constant G for Calculating Vibration-Controlled Floor Joist Spans

Forming Part of Note A-9.23.4.2.(2)

Floor Description Constant G

Floors with nailed

(1)

subfloor 0.00

Floor with nailed and field-glued

(2)

subfloor, vibration-controlled span greater than 3 m 0.10

Floor with nailed and field-glued

(2)

subfloor, vibration-controlled span 3 m or less 0.15

Notes to Table A-9.23.4.2.(2)-C:

(1) Common wire nails, spiral nails or wood screws can be considered equivalent for this purpose.

(2) Subfloor field-glued to floor joists with elastomeric adhesive complying with CAN/CGSB-71.26-M, “Adhesive for Field-Gluing Plywood to Lumber Framing for

Floor Systems.”

Example

Assumptions:

– basic dead load = 0.5 kPa

– topping dead load = 0.8 kPa

– total dead load = 1.3 kPa

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

The spacing of joists in the span tables can be conservatively adjusted to allow for the increased load by using the spans in Span

Table 9.23.4.2.-A for 600 mm spacing, but spacing the joists 400 mm apart. Similarly, floor beam span tables can be adjusted by using

4.8 m supported length spans for cases where the supported length equals 3.6 m.

A-9.23.8.3. Joint Location in Built-Up Beams.

Figure A-9.23.8.3.

Joint location in built-up beams

A-9.23.10.4.(1) Fingerjoined Lumber. NLGA 2014, “Standard Grading Rules for Canadian Lumber,” referenced in

Article 9.3.2.1., refers to two special product standards, SPS-1, “Fingerjoined Structural Lumber,” and SPS-3, “Fingerjoined “Vertical

Stud Use Only” Lumber,” produced by NLGA. Material identified as conforming to these standards is considered to meet the

requirements in this Sentence for joining with a structural adhesive. Lumber fingerjoined in accordance with SPS-3 should be used as

a vertical end-loaded member in compression only, where sustained bending or tension-loading conditions are not present, and where

the moisture content of the wood will not exceed 19%. Fingerjoined lumber may not be visually regraded or remanufactured into a

higher stress grade even if the quality of the lumber containing fingerjoints would otherwise warrant such regrading.

– live load = 1.9 kPa

– vibration limit per Note A-9.23.4.2.(2)

– deflection limit = 1/360

– ceiling attached directly to joists, no bridging

not more than

one joint per piece

in each span

no joints permitted

in the end spans

in this location

column

bearing plate

above column

joints in not more

than half the members

at these locations

( 150 mm)

–

( 150 mm)

EG00908B

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.23.10.6.(3) Single Studs at Sides of Openings.

Figure A-9.23.10.6.(3)-A

Single studs at openings in non-loadbearing interior walls

Figure A-9.23.10.6.(3)-B

Single studs at openings in all other walls

(a)

Configurations which comply

(a) full height studs both sides

(b) full height studs both sides and opening within stud space

Configurations which do not comply

(a) opening wider than stud space without full height studs

both sides

(b) opening narrower than but not within stud space

(a) (b) (c)

(b)

EC00296B

Configurations which comply

(a), (b), (c) openings all narrower than and within stud space;

no two full stud space width openings in adjacent

stud spaces

Configurations which do not comply

(a) opening wider than stud space

(b) opening narrower than but not within stud space

(a) (b) (c)

EC00296C

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

A-9.23.13. Bracing for Resistance to Lateral Loads. Subsection 9.23.14. along with

Articles 9.23.3.4., 9.23.3.5., 9.23.6.1., 9.23.9.8., 9.23.15.5., 9.29.5.8., 9.29.5.9., 9.29.6.3. and 9.29.9.3. provide explicit

requirements to address resistance to wind and earthquake loads in higher wind and earthquake regions of British Columbia.

A-9.23.13.1.

Bracing to Resist Lateral Loads in Low Load Locations

Of the 109

locations identified in Appendix C, 68 are locations where the seismic spectral response acceleration, S

(0.2), is less than or

equal to 0.70 and the 1-in-50 hourly wind pressure is less than 0.80 kPa. For buildings in these locations, Sentence 9.23.13.1.(2)

requires only that exterior walls be braced using the acceptable materials and fastening specified. There are no spacing or dimension

requirements for braced wall panels in these buildings.

Structural Design for Lateral Wind and Earthquake Loads

In cases where lateral load design is required, CWC 2014, “Engineering Guide for Wood Frame Construction,” provides acceptable

engineering solutions as an alternative to Part 4. The CWC Guide also contains alternative solutions and provides information on the

applicability of the Part 9 prescriptive structural requirements to further assist designers and building officials to identify the

appropriate design approach.

A-9.23.13.2.(1)(a)(i) Heavy Construction. “Heavy construction” refers to buildings with tile roofs, stucco walls or floors

with concrete topping, or that are clad with directly-applied heavyweight materials.

Heavyweight construction assemblies increase the lateral load on the structure during an earthquake. Assemblies should be considered

as heavyweight where their average dead weight is as follows (an additional partition weight of 0.5 kPa per floor is assumed):

• floor: 0.5 to 1.5 kPa

• roof: 0.5 to 1.0 kPa

• wall (vertical area): 0.32 to 1.2 kPa

Table A-9.23.13.

Application of Lateral Load Requirements

Applicable

Requirements

Wind (HWP) Earthquake S

(0.2)

Low to Moderate High Extreme Low to Moderate High Extreme High Extreme

HWP < 0.80 kPa

0.80 ≤ HWP

< 1.20 kPa

HWP ≥

1.20 kPa

(0.2) ≤ 0.70

0.70 < S

(0.2)

≤ 1.8

(0.2) > 1.8

0.70 < S

(0.2)

≤ 1.8

(0.2) > 1.8

All Construction All Construction Heavy Construction

(1)

Light Construction

Design requirements in

9.23.16.2., 9.27., 9.29.

(2)

N/A N/A X N/A N/A N/A N/A

Bracing requirements

in 9.23.13.

XXN/AXX

(3)(4)

N/A X

(4)(5)

N/A

Part 4 or CWC Guide X X X X X X X X

X = requirements are applicable

Notes to Table A-9.23.13.:

(1) See Note A-9.23.13.2.(1)(a)(i).

(2) Requirements apply to exterior walls only.

(3) Requirements apply where lowest exterior frame walls support not more than one floor.

(4) All constructions may include the support of a roof in addition to the stated number of floors.

(5) Requirements apply where lowest exterior frame walls support not more than two floors.

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

A-9.23.13.4. Braced Wall Bands. Article 9.23.13.4. specifies the required characteristics of braced wall bands and their

position in the building. Figures A-9.23.13.4.-A, A-9.23.13.4.-B and A-9.23.13.4.-C illustrate these requirements.

Figure A-9.23.13.4.-A

Braced wall bands in an example building section [Clauses 9.23.13.4.(1)(a), (b) and (d)]

EG00682A

braced wall band

braced wall panel

9.23.13.4.(1)(b):

braced wall band

max. 1.2 m wide

9.23.13.4.(1)(a):

braced wall band

full storey height

9.23.13.4.(1)(d):

braced wall band aligned

with braced wall bands on

storeys above and below

Effective December 10, 2018 to December 11, 2019

Division B: Acceptable Solutions Notes to Part 9 – Housing and Small Buildings

British Columbia Building Code 2018 Division B

Figure A-9.23.13.4.-B

Lapping bands and building perimeter within braced wall bands [Clause 9.23.13.4.(1)(c) and Sentence 9.23.13.4.(2)]

Figure A-9.23.13.4.-C

Braced wall band at change in floor level in split-level buildings [Sentence 9.23.13.4.(3)]

A-Table 9.23.13.5. Spacing of Braced Wall Bands and Braced Wall Panels. Identifying adjacent braced wall bands

and determining the spacing of braced wall panels and braced wall bands is not complicated where the building plan is orthogonal or

there are parallel braced wall bands: the adjacent braced wall band is the nearest parallel band. Figure Table A-9.23.13.5.-A

illustrates spacing.

EG00683A

9.23.13.4.(2):

building perimeter

within braced wall bands

9.23.13.4.(1)(c):

braced wall bands lap at both

ends with another braced wall

band so that the centre line of

one band extends to the far

side of the connecting band

braced wall band

braced wall panel

centre line of band

GG00171A

Effective December 10, 2018 to December 11, 2019

Notes to Part 9 – Housing and Small Buildings Division B: Acceptable Solutions

Division B

British Columbia Building Code 2018

Figure Table A-9.23.13.5.-A

Spacing of parallel braced wall bands and spacing of braced wall panels

Identifying and Spacing Adjacent Non-Parallel Braced Wall Bands

Identifying the adjacent braced wall band and the spacing between braced wall bands is more complicated where the building plan is

not orthogonal.

Where the plan is triangular, all braced wall bands intersect with the subject braced wall band. The prescriptive requirements in Part 9

do not apply to these cases and the building must be designed according to Part 4 with respect to lateral load resistance.

Where the braced wall bands are not parallel, the adjacent band is identified as follows using Figure Table A-9.23.13.5.-B as an

example:

1. Determine the mid-point of the centre line of the subject braced wall band (A);

2. Project a perpendicular line from this mid-point (B);

3. The first braced wall band encountered is the adjacent braced wall band (C);

4. Where the projected line encounters an intersection point between two braced wall bands, either wall band may be identified as the

adjacent braced wall band (complex cases).

The spacing of non-parallel braced wall bands is measured as the greatest distance between the centre lines of the bands.

EG00684A

braced wall band

centre line of braced wall band

braced wall panel

A A

Where

A = distance between centre lines of adjacent braced wall bands

B = distance between panel edges

C = distance from end of braced wall band to end of first braced

wall panel

Effective December 10, 2018 to December 11, 2019

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