Completed second storey addition on a brick Ontario bungalow with new upper floor, large windows, and asphalt roof
Home Building Guides, Home Renovation

2nd Storey Addition Cost Ontario 2026: What to Budget and Expect

A 2nd storey addition cost in Ontario ranges from $375 to $550 per square foot in 2026, with Toronto and GTA projects often reaching $400–$700+. For a standard 800–1,000 sq ft second storey, total costs including permits and engineering typically fall between $280,000 and $550,000.