The Ontario Building Code | Increase in Occupant Load
11.4.3.3. Increase in Occupant Load
(1) Where the performance level of an existing buildingis reduced under Sentence 11.4.2.2.(1), (2) or (3), the buildingshall be evaluated, and the early warning and evacuation systems shall be upgraded, in conformance with the applicable requirements of Table 11.4.3.3.
(2) Sentence (1) does not apply in a Group C occupancy where the new total occupant load is,
(a) 14 persons or fewer in a boarding, lodging or rooming house, except that where theoccupant load is between 10 and 15 persons, an interconnected system of smoke alarms in corridors near stairways is required, or
(b) 16 persons or fewer in a building containing residential suiteswhich are dwelling units, except that where the occupant load is between 10 and 17 persons, an interconnected system of smoke alarms in corridors near stairways is required.
(3) Where the performance level of an existing buildingis reduced under Sentence 11.4.2.2.(1), additional constructionshall be required in order that the building or part of the building subject to the increase in occupant load conforms to the requirements of Sentence 6.2.2.1.(2), Subsection 3.7.4. and Article 9.31.1.1.
In Plain Language
Where a renovation increases a building's occupant load and reduces its performance level, the building must be evaluated and its early warning and evacuation systems upgraded per the referenced table, as set out in this article, ensuring more people can still escape safely.
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.