A house extension costs $250 to $450 per square foot in Canada. See 2026 prices by extension type and city, what's included in a quote, and zoning requirements.

A house extension in Canada costs $250 to $450 per square foot in 2026, putting most full additions between $100,000 and $300,000. A bump-out starts near $30,000, while a second-storey addition in Toronto or Vancouver regularly passes $500,000.

House Extension Cost in Canada: What to Budget in 2026

Learn the cost of foundation excavation and waterproofing in Quebec, including price per linear foot, materials, drainage, and factors that affect the total budget.

In Quebec, poured concrete and concrete block foundations are exposed to particularly harsh climate conditions. Rapid spring snowmelt, combined with clay or poorly draining soils, can create significant hydrostatic pressure at the base of basement walls. When moisture begins penetrating the structure or water starts pooling on the concrete slab, major repairs may be required.

Foundation Excavation and Waterproofing Costs in Quebec

French drain, sump pump, or waterproofing membrane? Learn how each system works, what it costs, and how they help protect foundations from water damage.

In Quebec, basement water infiltration is the most common type of residential insurance claim. According to the&nbsp;Insurance Bureau of Canada, water damage accounted for 68% of home insurance claims paid in Quebec in 2024. Harsh winters, major spring thaws, and heavy summer rainfall place considerable hydrostatic pressure on the below-grade portions of our homes.

French Drain vs. Sump Pump: Roles and Foundation Waterproofing in Quebec

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