Home additions in Toronto
Lots are narrow, side passages are tight, and material often comes in from the street or a rear lane, so the site plan is written before the first delivery. The addition goes up as a shell before the wall into the house is opened, so most families stay through the work, and the machine access to the back yard is planned at the site walk. An addition is more house on the same lot, and the job lives or dies at the tie-in: where the new foundation meets the old, where the roofs meet, and where the floors have to line up.
Toronto, on the ground.
Toronto's stock runs from 1890s brick semis downtown to 1950s bungalows at the edges, on lots that are rarely wider than 30 feet. On that stock in Toronto, the rear addition with a new kitchen across the back is the most common brief, with two-storey additions where the lot has the depth. In Toronto the usual brief is a second storey on a semi, a rear addition with a new kitchen, or a laneway suite behind a house that already has one.
Read more about building in Toronto or the full home additions page.
On the drawing.
Zoning check of setbacks and lot coverage before design so the addition fits the lot
Engineered drawings and a rendering of the addition inside and out
Building permit filed and followed by us, with any conservation review handled first
Excavation, new foundation, framing, roof and envelope tied into the existing structure
Openings cut into the old house under shoring, with beams sized by the engineer
Mechanical and electrical extended, finishes from the catalogue, a deficiency walk and a written warranty
Paper first.
An addition needs a building permit with engineered drawings, and the setbacks and lot coverage in the zoning by-law decide whether the design goes straight to permit or to the Committee of Adjustment first. Toronto Building issues the permit, and any design outside the zoning envelope goes to the Committee of Adjustment first, so the zoning check comes before the drawings are final.
- A building permit with engineered drawings is required in every GTA municipality.
- Setbacks and lot coverage come from the zoning by-law; a design outside them goes to the Committee of Adjustment first.
- Lots inside a conservation authority's regulated area need its review before the permit.
- Heritage listing adds a review of anything visible from the street.
The paperwork wall: WSIB, insurance, licences, the HCRA status and the warranty, on one page and dated.
| Driver | What we look at |
|---|---|
| Floor area and storeys | A single-storey rear addition and a two-storey one share a foundation but not much else. |
| The tie-in | How much of the existing rear wall opens up, and whether the roofs meet cleanly or the old roof is reworked. |
| Foundation type | Full basement under the addition, crawl space or slab, and what the soil and the water table allow. |
| Lot constraints | Setbacks, lot coverage, a ravine or conservation edge, and how a machine reaches the back yard. |
| Finish level | Kitchen and bathroom scope inside the addition, chosen from the catalogue. |
No price per square foot on this site. The zoning check and the drawings set the number, and the number holds because of them.
The zoning by-law sets rear and side setbacks and a lot coverage limit. We run the check before design so the addition you draw is one the City of Toronto (Toronto Building) will approve.
Usually. The shell goes up first, the wall between the house and the addition opens last, and dust walls seal the route in between.
Often, yes. The shared wall is the engineering question: the new floor loads onto a party wall the neighbour also owns, so the drawings have to show how the load is carried without touching their side. We check the by-law height limit for the street before you commit to drawings.
It needs to sit on a public laneway, with a route for a fire hose from the street and enough lot depth for the setbacks. Garden suites cover lots without a lane. We check the lot against the by-law before you spend anything on drawings.