Basement underpinning in North York
Lots are wide enough for a crane and a bin in the driveway, but many streets are lined with new builds, so the by-law envelope is well defined. 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.
North York, on the ground.
North York is 1950s bungalows on 50 foot lots, many already replaced by two-storey custom homes, with ravine lots along the Don and Humber tributaries. Those basements in North York were never meant to be lived under, and lowering the floor is what turns them into a suite or a real family room. In North York the brief is usually a custom home on a tear-down lot, a second storey on a bungalow worth keeping, or a whole-home renovation with a new rear wall.
Read more about building in North York 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. Toronto Building issues the permit; ravine lots add a conservation authority review and the City's ravine by-law before the application goes in.
- 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.
The City of Toronto, through Toronto Building. North York has had no separate permit office since 1998.
The conservation authority reviews anything in its regulated area, and Toronto's ravine by-law sets where you can build and what you can remove. That review happens before the permit, so it goes into the schedule from the start.