The Ontario Building Code | Wall Enclosing Attic or Roof Space
3.2.3.3. wall Enclosing attic or Roof Space
(1) An exterior wall enclosing an attic or roof space and located above an exposing building face, shall be constructed in conformance with the requirements for the exposing building face.
In Plain Language
This clause sets out how to measure the area of an exposing building face, the portion of an exterior wall facing a given limiting distance, since that area (combined with the limiting distance) determines the maximum percentage of unprotected openings allowed under Table 3.2.3.1.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.