What a house foundation costs in Ontario

By the Give Me The Cost estimating team · Methods reviewed by a senior GTA estimator (25+ years in the field) · Updated September 2026
A full basement foundation for a typical Ontario house runs $55,000 to $110,000 in 2026 — roughly $45 to $75 per square foot of footprint. That covers excavation, footings, foundation walls, slab, drainage and backfill. The spread is wide because the two biggest variables, soil condition and dig depth, are not known until someone tests the ground.

A foundation is four separate trades, not one price

Foundation quotes usually arrive as a single number, which is why they are so hard to compare. Underneath, a foundation is four measurable packages, each priced in its own unit:

PackageMeasured inTypical share
Excavation, haul and backfillCubic yards (loose, on the truck)20–30%
Concrete supply and placementCubic metres by mix strength25–35%
FormworkSquare metres of contact area20–30%
Reinforcing steelTonnes8–15%

Drainage, damproofing, weeping tile and granular fill sit on top of those four. A quote that does not break out at least concrete, formwork and rebar is not comparable to another quote.

What each piece runs in 2026

ItemUnitOntario 2026
Excavation and disposalper loose cubic yard$28–$55
Concrete supply, 25 MPaper m³$210–$255
Concrete supply, 30 MPa F-2per m³$235–$285
Concrete supply, 32 MPa C-2per m³$255–$310
Formwork, wall, both facesper m² contact area$55–$95
Formwork, single-faced against shoringper m²2.5× the two-sided rate
Rebar supply and install, 15Mper tonne$1,800–$2,400
Weeping tile, drainage layer, damproofingper linear foot of wall$22–$40

Supply-and-install ranges for southern Ontario, 2026. Pumping, winter heating and hoarding are extra. See the material price check for current supply pricing.

Concrete strength is not one price

This is the detail that catches homeowners comparing quotes. Concrete is not sold by strength alone — it is sold by strength and exposure class, and the class is what picks the actual mix. Two lines both reading 30 MPa can be completely different products at different prices.

A structural drawing set specifies these element by element in a concrete schedule on the general notes sheet. If your quote does not name the strength and class for each element, nobody has read that schedule. The concrete takeoff guide walks through how the volume is measured and grouped.

Foundation types, and what changes the price

Strip footings and foundation walls (most houses)

The standard. Continuous footings under the perimeter and party walls, pad footings under posts, foundation walls formed and poured on top, slab on grade inside. This is the cheapest per square foot and what most quotes assume.

Raft or mat foundation

A continuous slab, typically 600 to 900 mm thick with a rebar mat top and bottom, used where bearing capacity is poor or loads are high. It is not a small upgrade — it is several times the concrete volume and several times the reinforcing tonnage of a strip footing on the same footprint.

Slab on grade, no basement

Cheapest option, and common on smaller builds and garages. Still needs footings below frost around the perimeter — a minimum of 1.2 m below finished grade in most of southern Ontario, deeper for unheated areas.

Piles or caissons

Used where competent soil is deep. Priced per pile by depth and diameter, and almost always the result of a geotechnical report rather than a design preference.

The five things that move a foundation number most

  1. The geotechnical report. Bearing capacity decides footing sizes, and low capacity can force a raft. Nobody can quote a foundation honestly without one.
  2. Dig depth. Excavation is priced on volume, and volume scales with depth across the whole footprint.
  3. Access. A machine that cannot reach the back of the lot means conveyor or hand work at several times the rate.
  4. Groundwater. Dewatering during construction is a separate cost and is usually excluded from a base quote.
  5. Frost depth and unheated areas. Footings under garages and porches go deeper than footings under heated space.

What gets left out of foundation quotes

Checking a foundation quote against the drawings

Everything above is measurable before anyone breaks ground. Footing sizes and lengths are on the foundation plan. Wall heights are in the sections. Concrete strengths and exposure classes are in the schedule on the general notes. Rebar is in the footing schedule. Give Me The Cost reads a structural set and returns the concrete volume by mix, the formwork contact area, and the rebar tonnage, so you can put a quote beside the drawings rather than beside another quote. Start with what a quantity takeoff is, or the formwork guide for how contact area is measured.

Want your project's real quantities, not a range off a blog?
Upload your drawings and get an actual material takeoff — every division, whole building — with an Ontario Building Code check.
Get my takeoff →   Free calculators

Frequently asked questions

How much does a foundation cost for a house in Ontario?
A full basement foundation for a typical Ontario house runs $55,000 to $110,000 in 2026, roughly $45 to $75 per square foot of footprint, covering excavation, footings, walls, slab, drainage and backfill.

How much does concrete cost per cubic metre in Ontario in 2026?
Supply pricing runs roughly $210 to $255 per cubic metre for 25 MPa, $235 to $285 for 30 MPa F-2, and $255 to $310 for 32 MPa C-2. Placement, pumping and finishing are additional.

Why do two foundation quotes differ by tens of thousands?
Usually because they assume different things: different dig depths, different soil, one carrying disposal at loose volume and one at bank volume, one including dewatering and one excluding it, or different concrete strengths and exposure classes. A quote broken into concrete, formwork and rebar is comparable. A single lump sum is not.

How deep do footings have to be in Ontario?
Below the frost line. In most of southern Ontario that means a minimum of 1.2 m below finished grade for heated areas, and deeper under unheated areas such as garages, porches and detached structures. Local requirements vary, so confirm with your municipality.

Is a raft foundation more expensive than footings?
Substantially. A raft is a continuous slab, typically 600 to 900 mm thick with a rebar mat top and bottom, so it uses several times the concrete volume and several times the reinforcing of strip footings on the same footprint. It is specified when the soil cannot carry concentrated loads, not chosen for preference.