RTA · Houses with a Secondary Suite
9.10.11.2 Firewalls Not Required
not be constructed as a firewall, provided it is constructed as a fire separation having not less than a 1 h fire-resistance rating, where the party wall separates
a) two dwelling units where there is no dwelling unit above another dwelling unit,
b) a dwelling unit and a house with a secondary suite including their common spaces, or
c) two houses with a secondary suite including their common spaces.
2) Where a building of residential occupancy contains more than 2 houses, a party wall that separates any 2
adjacent houses with a secondary suite from the rest of the building shall be constructed as a firewall to create
separate buildings each containing no more than 2 adjacent houses with a secondary suite.