The Ontario Building Code | Method of Measurement
9.5.1.2. Method of Measurement
(1) Except as otherwise specified in this Part, the areas, dimensions and heights of rooms or spaces shall be measured between finished wall surfaces and between finished floor and ceiling surfaces.
In Plain Language
This article sets out the method of measurement used to calculate room and space areas throughout this Section, ensuring consistent measurement for the minimum area requirements ahead.
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.