Generally, an architect is not required by law (Architects Act, Chapter A-21) for the construction, enlargement, reconstruction, renovation or alteration of:
-A detached single-family building;
-A single-family semi-detached or attached building, or a multi-family building (4 units maximum) that has a maximum height of 2 storeys and a maximum gross area of 300 m2 (areas above ground, from exterior face of walls).
An architect is not required for the alteration and renovation of the interior layout if the occupancy remains unchanged and no modifications are made to the structure, the fire separations or the exterior cladding.
Note: The number of basements and the use may have some impact on the above requirements.