Buildings Separated by Firewalls

 Where a firewall divides a building, each portion of the building is considered as a separate building for the determination of building size

Most walls that separate one property from another are required to be firewalls (walls between semi-detached and row houses are exceptions to this rule). Firewalls are fire separations that have special features to ensure their stability in the event of a fire (NBC Subsection 3.1.10.), so that, should the building on one side of the firewall be destroyed, the firewall and the building on the other side will remain.

Firewalls may be voluntarily used to reduce the building area in order to take advantage of certain fire and structural concessions permitted for smaller buildings. Firewalls are frequently used to create buildings of 600 m2 (6 458 ft.2) that fall within the scope of NBC Part 9. For example, in some row houses, ordinary fire separations are used between most units, while firewalls are used at 600 m2 (6 458 ft.2) intervals.

Quoted from Illustrated User's Guide - NBC2015

#building #property #firewall