The Ontario Building Code | Maximum Openings
3.1.8.6. Maximum openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings
(1) The size of an opening in an interior fire separation required to be protected with a closureshall be not more than 11 m2, with no dimension more than 3.7 m, if a fire compartment on either side of the fire separation is not sprinklered.
(2) The size of an opening in an interior fire separation required to be protected with a closureshall be not more than 22 m2, with no dimension more than 6 m, provided the fire compartments on both sides of thefire separation are sprinklered.
In Plain Language
Openings in an interior fire separation protected by a closure are capped at 11 m² (max 3.7 m in any dimension) if either adjoining compartment isn't sprinklered, or 22 m² (max 6 m) if both sides are sprinklered.
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.