Converting an attached garage to living space is one of the more complex Ontario renovation projects because it touches zoning, building code, and parking requirements simultaneously.
Zoning: Parking Requirements First
Check your zoning bylaw for required off-street parking spaces before anything else. In Toronto, losing a required parking space requires a Minor Variance from the Committee of Adjustment ($1,000-$3,000 in fees, 3-6 month timeline). Some municipalities have exemptions for accessory dwelling units.
Building Permit Always Required
The new habitable space must meet Ontario Building Code: minimum 2.1m ceiling height, minimum window area for natural light and egress, insulation to current energy code values, proper ventilation, and electrical to current code.
Typical Scope of Work
Insulating walls, ceiling, and floor slab. Installing heating (extending forced-air ducting or adding hydronic in-floor). Installing compliant windows. New electrical circuits. Replacing garage door with insulated wall. Drywall, flooring, and finish work.
Costs in Ontario
Basic single-car garage conversion: $20,000-$40,000 including permits.
With bathroom rough-in: $35,000-$60,000.
Full bathroom addition: +$10,000-$20,000.
Common Mistakes
Skipping the parking variance check and having the conversion flagged during sale. Not insulating the floor slab (fails energy code inspection). Improper vapour barrier leading to moisture problems.
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