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

13 dimensions art inc.

Lanaudiere (D'Autray)

Lanaudière (Joliette)

Lanaudière (L'Assomption)

Lanaudiere (Les Moulins)

Lanaudiere (Matawinie)

Lanaudière (Montcalm)

Laurentides (Argenteuil)

Laurentides (Deux-Montagnes)

Laurentides (La Riviere-du-Nord)

Laurentides (Les Pays-d'en-Haut)

Laurentides (Mirabel)

Laurentides (Therese-De Blainville)

Laval

Mont-Laurier, Riviere-Rouge and surrounding area

Montreal (Center: Saint-Leonard to Notre Dame de Grace)

Montreal (East: Anjou to bridge)

Montreal (Nord: Saint-Laurent to Montreal-Nord)

Montreal (South: Lachine to Verdun)

Montréal (West Island: Pierrefonds to Senneville)

St-Sauveur, Mont Tremblant, Ste-Adele and surrounding area

Basement renovation – Without plumbing or electrical

Commercial maintenance

Concrete cutting

Culvert

Demolition

Drywall installation only

Drywall installation, finishing & paint

Drywall taping

Exterior concrete surface

Exterior painting

Exterior renovation

Floor installation

Foundation excavation

French drain

Grading

Home maintenance

Interior painting

Interior renovation – Without plumbing, electrical or structure

Interior wall insulation

Post-construction or renovation cleanup

Post-disaster renovation

Pressure washing

Sod and seeding

Tree trimming and pruning

Wood or composite balcony

13 dimensions art inc.

13 dimensions art inc.

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