The Ontario Building Code | Separation of Residential Occupancies
220.127.116.11. Separation of residential Occupancies
(1) Except as provided in Sentences (2) and (4), residential occupancies shall be separated from all other major occupancies by a fire separation having a fire-resistance rating of not less than 1 h.
(2) Except as provided in Sentence (3), a major occupancyclassified as a residential occupancy, including live/work units, shall be separated from other major occupancies classified as mercantileor medium hazard industrial occupancies by a fire separation having a fire-resistance rating of not less than 2 h.
(3) Where not more than 2 dwelling units or live/work units are located in a buildingcontaining a mercantile occupancy, such mercantile occupancy shall be separated from the dwelling units or live/work unitsby a fire separation having not less than 1 h fire-resistance rating.
(4) The requirement for fire separations between major occupancies in Sentence (1) is waived for the occupancies allowed within live/work units.