Concrete foundations across Toronto and the GTA
WSIB cleared|$5M liability insured
WSIB cleared|$5M liability insured

Underpinning and basement lowering

Basement underpinning and lowering in Toronto and the GTA

Underpinning a foundation means building new footings below the old ones, one short section at a time, so the basement can be lowered.

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Why GSS

Why homeowners and builders choose GSS

01

Your schedule stays on track

We own our forming system, so your pour never waits on a rental yard or another crew’s calendar.

02

One company, footing to roof

Concrete and framing under one contract. No gap between trades, and no arguing over walls that are out of square.

03

Built right, inspected at every stage

Built to your engineered drawings. Footings are inspected before every pour, and underpinning follows the engineer’s sequence.

04

You’re covered on every job

WSIB cleared with $5 million in liability insurance. Certificates on request, before we start.

Underpinning a foundation means building new footings below the old ones, one short section at a time, so the basement can be lowered. It is structural work, and we follow the engineer’s design and sequence from the first section to the last.

Our own forms

No waiting on rental stock or another crew

Pour date in writing

The date we give you is the date we pour

WSIB cleared

Clearance certificate on request

Fully insured

$5 million liability insurance on every job

Why Toronto homeowners lower their basements

More ceiling height for a legal basement apartment. A walkout or separate entrance. More living space without building up or out. Basement lowering in Toronto usually means underpinning, because it keeps the full room.

How foundation underpinning works

  1. Engineer’s design. A professional engineer designs the underpinning and the order the sections are dug. We arrange the engineer, and their design and site reviews are part of our price.
  2. Building permit. The City of Toronto requires a permit for underpinning. We don’t dig until it is issued.
  3. First engineer review. The City requires engineer testing and a report at the start of the work.
  4. Sections. We dig and pour the underpinning footings in numbered sections, so your house stays supported the whole time.
  5. Last engineer review and inspection. Testing and a report at the end, then the City inspection.
  6. New basement slab. We pour the new basement floor at the new height.

When the City requires an engineer

A professional engineer must design the work and review it on site when the new footing goes below your neighbour’s footing and within the soil’s angle of repose, when the unsupported height is over 1.2 metres, or when the soil is clay or silt. In every case, the City wants engineer testing and reports at the first and last stages before it passes the inspection.

Recent work

Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services
Underpinning and basement lowering by Grand Structural Services

Ready for a price? Send your drawings and we’ll reply the same day.

Underpinning or benching?

Benching lowers the floor but leaves a concrete ledge, or bench footing, around the inside of the walls. It costs less but takes floor space. Underpinning goes under the existing footing, so you keep the full room. We build both.

Basement walkouts and separate entrances

A walkout needs the foundation cut, new footings and walls around the opening, and concrete stairs or a landing. In Toronto it falls under the same underpinning permit, and we build the concrete and structure as one job.

What does underpinning cost in Toronto?

It depends on the length of wall, how deep we go, the soil, access and whether you add a walkout. Send the address and your basement height, or the engineer’s drawings, and we’ll give you a clear, line-by-line price.

Questions we get asked

Yes. The City requires a building permit to underpin or lower a basement, and to add a below-grade entrance.

Often, yes. See the City’s rules above. Even where an engineer isn’t needed for the design, the City wants engineer reports at the start and end of the work.

Underpinning builds new footings under the old ones and keeps the full room. Benching leaves a concrete ledge around the walls and costs less.

It can, if it is done in the wrong order. That is why the engineer sets the sequence and, where the new footing goes below the neighbour’s, reviews the work on site.

We can usually start within 1 to 2 weeks of a signed quote, once the permit is issued. The length of the job depends on the number of sections, the engineer’s sequence and the inspections. We give you the dates in writing.

Thinking about lowering your basement?

Send the address and your ceiling height. We’ll tell you what it needs, arrange the engineer and handle the permit.