Home Additions in the GTA: The Complete 2026 Guide
Adding square footage is the highest-impact option for homeowners with equity who need more space.
Rear Addition (Ground Floor)
Size: 200-500 sq ft typical
Cost: $250,000-$450,000 complete
Includes new foundation, exterior walls, roof framing, insulation, and full interior finish.
Requires architectural drawings, structural engineering, building permit.
Toronto permit lead time: 10-20 weeks for complex additions. Apply early.
Second Storey Addition (Add-a-Level)
Size: 800-1,200+ sq ft added
Cost: $200,000-$380,000
Converts a bungalow or 1.5-storey into a full two-storey. Includes structural assessment of existing walls, new roof framing, exterior cladding, and interior completion.
Best ROI markets: Scarborough, Etobicoke, North York, 905 bungalow stock.
Combined Rear + Second Storey
Cost: $380,000-$600,000+
Highest complexity. Best cost per square foot added when both types of space are needed.
Bump-Out (Small Extension)
Size: 10-50 sq ft
Cost: $40,000-$120,000
Often no new foundation required – cantilevered framing. Great for kitchen extension or breakfast nook.
Zoning Reality Check
Toronto’s bylaw 569-2013 governs lot coverage, setbacks, and shadow studies. Always verify zoning BEFORE committing to design fees.
LF Builders – addition specialists across the GTA: lfbuilders.ca
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