What maximum gross area for a 2 storey building for assembly occupancy typically requires an architect?

In most jurisdictions in Canada, the requirement for an architect to be involved in the design and permitting of an assembly occupancy building often hinges on the size of the building. Typically, for assembly occupancies, a threshold of 150 square metres is widely recognized. When a building exceeds this area, it generally necessitates professional input from a licensed architect to ensure compliance with health, safety, and building code regulations.

The 150 square metre threshold is derived from building codes that aim to protect the health and safety of the public in assembly spaces, which can include places like theatres, community halls, and meeting rooms. Given that assembly occupancies can involve large groups of people, building design at this scale requires a comprehensive understanding of structural integrity, fire safety, accessibility, and other critical factors that a qualified architect is trained to manage.

While other area thresholds may apply to different types of occupancies or specific local codes, in the context of assembly occupancy, 150 square metres is effectively the benchmark for requiring architectural involvement. Thus, this answer aligns with standard practices and regulations across many jurisdictions.