The Ontario Building Code | Structural
11.4.2.1. Structural
(1) The performance level of an existing buildingis reduced where after proposed construction in all or part of an existing building,
(a) the major occupancy will change to a different major occupancy,
(b) the occupant load will increase by more than 15%, or
(c) the live load will increase due to change in use within the same major occupancy,
and the existing structural floor and roof framing systems and their supporting members after the construction are not adequate to support the proposed dead loads and live loads.
In Plain Language
Structural requirements for a renovated building are set out in this article, addressing how existing structural elements are evaluated against current standards.
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.