Basement underpinning in Scarborough
Driveways and side yards are wide enough for a crane and a material drop, so less is carried by hand than in the old city. The work is in the basement and the house stays supported throughout, so most families stay; each section is dug, formed, poured and inspected before the next. Underpinning lowers a basement floor by extending the foundation walls down in short engineered sections, one at a time, so the house is never sitting on an unsupported wall. The result is legal ceiling height for a suite or a family room.
Scarborough, on the ground.
Scarborough is mostly 1950s to 1970s bungalows and side-splits on 40 to 50 foot lots, the easiest houses in the city to add a floor to. Those basements in Scarborough were never meant to be lived under, and lowering the floor is what turns them into a suite or a real family room. The Scarborough brief is usually a second storey on a bungalow, a rear addition with an open kitchen, or a lowered basement for a legal suite.
Read more about building in Scarborough or the full basement underpinning page.
On the drawing.
A site walk with measurements of the existing ceiling height and a look at the footings
Engineered drawings with the underpinning sequence and the new footing depth
Building permit filed and followed by us
Excavation and pours in numbered sections, each inspected before the next
New slab, drainage, sump and waterproofing where the drawings call for them
A deficiency walk, and a written warranty
Paper first.
Underpinning needs a building permit with engineered drawings, and each section is inspected before the next one is dug; a suite that follows needs its own permit. Permits come from Toronto Building; Scarborough has had no separate office since amalgamation in 1998, and lots near the Bluffs add a conservation review.
- A building permit with engineered drawings is required in every GTA municipality.
- Each underpinning section is inspected before the next one is dug.
- On a semi, the drawings address the shared wall and the neighbour's foundation.
- A suite that follows needs its own permit for the plumbing, the egress and the fire separation.
The paperwork wall: WSIB, insurance, licences, the HCRA status and the warranty, on one page and dated.
| Driver | What we look at |
|---|---|
| How far the floor drops | Every extra inch of depth is more excavation and a deeper footing. |
| Perimeter length | The number of underpinning sections is set by the wall length, and each one is dug, formed and poured on its own. |
| Soil and water | Clay, sand and a high water table each change the sequence and the drainage. |
| Benching instead | Where the soil or the neighbour's foundation rules out underpinning, benching lowers the floor with a ledge along the wall. |
| What follows | A lowered basement is usually the start of a suite, and the plumbing and finishes come after the slab. |
No price per linear foot on this site. The site walk and the engineer's drawings set the number.
Usually. The site walk measures the ceiling height and checks the footings, and the engineer draws the sequence. the City of Toronto (Toronto Building) issues the permit and inspects each section.
Usually, yes. The house is supported throughout and the work stays in the basement. Noise and dust are real, and the basement is out of use for the duration.
Most can, with new footings at the corners or a steel frame to carry the load, which the engineer decides after looking at the foundation. We open a test pit at the site walk stage so the answer comes before the drawings, not after.
The City of Toronto. Scarborough has been inside the City since 1998, so the application goes to Toronto Building.