Can you add a basement apartment in Vaudreuil-Dorion?

The rules, in short

• An accessory dwelling unit is allowed only in a detached single-family house, even if the zone grid does not provide for it. (art. 6.34, para. 1°)
• At most 100 m² and 2 bedrooms; above 80 m² (or 80% of the main dwelling), it must be built to the standards of a main dwelling. (art. 6.34, para. 2° and 3°)
• Façade unchanged; access through the main entrance or a side or rear entrance; one address only; no parking space required. (art. 6.34, para. 4° to 7°)
• Adding a dwelling unit requires a building permit for the conversion, whatever the area altered. (By-law 1871, art. 4.1, para. 1°)

Summary by Radar Foncier, in our own words: the official French text of the by-law, linked above, prevails.

Applying in Vaudreuil-Dorion

• Cost: Fees By-law 1709: fence $15.50; above-ground pool $30.50; in-ground pool $51; hot tub $30.50; accessory building (residential) $51; accessory structure $30.50
• Urban planning department: 450 455-3371 (Permits and Inspections Division)
• Permits on the municipality's website