The Ontario Building Code | Area and Location of Exposing Building Face
188.8.131.52. Area and Location of Exposing building Face
(1) The area of an exposing building face shall be,
(a) taken as the exterior wall area facing in one direction on any side of a building, and
(b) calculated as,
(i) the total area measured from the finished ground level to the uppermost ceiling, or
(ii) the area for each fire compartment, where a building is divided into fire compartments by fire separations with fire-resistance ratings not less than 45 min.
(2) For the purpose of using Table 184.108.40.206. to determine the maximum aggregate area of unprotected openings permitted in an irregularly-shaped or skewed exterior wall, the location of the exposing building face shall be taken as a vertical plane located so that there are no unprotected openingsbetween the vertical plane and the line to which limiting distance is measured.
(3) For the purpose of using Table 220.127.116.11. to determine the required type of construction, cladding and fire-resistance ratingfor an irregularly-shaped or skewed exterior wall,
(a) the exposing building face is permitted to be divided into any number of portions and the fire-resistance rating, type of cladding and percentage of unprotected openings limitations is permitted to be determined individually for each portion based on the limiting distance for each portion so divided,
(b) the exposing building face shall be taken as the projection of the exterior wall onto a vertical plane located so that no portion of the exterior wall of the building is between the vertical plane and the line to which the limiting distance is established in Clause (a), and
(c) for the purpose of determining the actual area of unprotected openings permitted in an exterior wall, the unprotected openings shall be projected onto the vertical plane established in Clause (b).
(4) The required limiting distance for an exposing building face is permitted to be measured to a point beyond the property line that is not the centre line of a street, lane or public thoroughfare if,
(a) the owners of the properties on which the limiting distance is measured and the municipality enter into an agreement in which such owners agree that,
(i) each owner covenants that, for the benefit of land owned by the other covenantors, the owner will not construct a buildingon his or her property unless the limiting distancefor exposing building faces in respect of the proposed construction is measured in accordance with the agreement,
(ii) the covenants contained in the agreement are intended to run with the lands, and the agreement shall be binding on the parties and their respective heirs, executors, administrators, successors and assigns,
(iii) the agreement shall not be amended or deleted from title without the consent of the municipality, and
(iv) they will comply with such other conditions as the municipality considers necessary, including indemnification of the municipalityby the other parties, and
(b) the agreement referred to in Clause (a) is registered against the title of the properties to which it applies.
(5) Where an agreement referred to in Sentence (4) is registered against the title of a property, the limiting distance for exposing building faces in respect of the construction of any buildingson the property shall be measured to the point referred to in the agreement.