How much does basement underpinning cost?

With Zigma Group, basement underpinning starts from $320 per linear ft. Prices are in Canadian dollars before HST, as of October 2026, and are confirmed after a site visit. The main factors are length of foundation wall to be underpinned; how far the floor is lowered; and shared walls, access and soil conditions.

What is the difference between underpinning and bench footing?

Underpinning extends the existing foundation walls straight down, keeping the full floor area. Bench footing leaves the old footing in place and builds a concrete ledge inside it, which is simpler but takes floor space around the perimeter.

Is underpinning safe for my house?

It is a standard method when designed by an engineer and done in the specified sequence under a permit, with inspections at each stage.

Can you underpin a semi-detached house?

Yes, but the shared wall needs particular care in the engineering, and the neighbour usually has to be involved. We explain what that means for your property before you commit.

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Basement Underpinning

Basements · Greater Toronto Area

Basement Underpinning and Lowering in the GTA

Underpinning extends the foundation deeper so the basement floor can be lowered. It is structural work that turns a low, unusable basement into a full-height floor.

Call (647) 718-3913 Book a consultation

Foundation work on site with steel reinforcement cages and formwork — From our Damavand project

Scope

What is included.

Structural engineer's design and drawings
Building permit and inspections
Staged excavation and concrete in sections
New floor slab and drainage
Waterproofing and sump systems
Bench footing as an alternative where suitable

Cost

What it costs.

From $320per linear ft

What moves the price

Length of foundation wall to be underpinned
How far the floor is lowered
Shared walls, access and soil conditions

Prices are in Canadian dollars before HST, as of October 2026. Every project is confirmed with a written quote after a site visit.

Before you start

What to know.

Permits and engineering
Underpinning always needs a building permit and a design by a professional engineer. The work is done in a set sequence of short sections so the house stays supported throughout.
Shared walls
In semi-detached and row houses the foundation is shared, so the neighbour's side has to be considered in the engineering and often in a written agreement.
Do it with the rest
Lowering the floor is the right moment to replace old drains, add a bathroom rough-in and waterproof from the inside.

How we work

One team for every stage.

AssessWe survey the house as it stands.
Design and permitsDrawings and approvals before work starts.
Strip-outWhat is worn out comes off.
RebuildStructure, wiring, plumbing and walls.
FinishesCabinetry, tile, floors and paint.
HandoverWalkthrough and documents.

Questions

Basement Underpinning: the short answers.

How much does basement underpinning cost?: With Zigma Group, basement underpinning starts from $320 per linear ft. Prices are in Canadian dollars before HST, as of October 2026, and are confirmed after a site visit. The main factors are length of foundation wall to be underpinned; how far the floor is lowered; and shared walls, access and soil conditions.
What is the difference between underpinning and bench footing?: Underpinning extends the existing foundation walls straight down, keeping the full floor area. Bench footing leaves the old footing in place and builds a concrete ledge inside it, which is simpler but takes floor space around the perimeter.
Is underpinning safe for my house?: It is a standard method when designed by an engineer and done in the specified sequence under a permit, with inspections at each stage.
Can you underpin a semi-detached house?: Yes, but the shared wall needs particular care in the engineering, and the neighbour usually has to be involved. We explain what that means for your property before you commit.

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