Permitted, inspected, registered basement apartments that pass the first time.
- Feasibility & design
- 1 — 2 weeks
- Permit review
- 4 — 12 weeks
- Construction
- 8 — 14 weeks
- Inspections & registration
- 2 — 4 weeks
Legal Basement in Toronto — the short answer
A legal basement apartment — formally an Additional Residential Unit or second suite — is a self-contained dwelling in a basement that has been built to the Ontario Building Code, approved under a building permit, inspected, and where required registered with the municipality. Under Bill 23 (More Homes Built Faster Act), most detached, semi-detached and townhouse properties in Ontario may add one ARU as-of-right. In Toronto, that work is permitted and inspected through Toronto Building. Toronto permits second suites as-of-right in most residential zones under Bill 23, but restricts new entrances on the front façade that make a house read as a duplex — side and rear entrances are usually the workable route. Heritage Conservation Districts and ravine protection add review steps that we check before design.
Whether a Toronto basement can become a legal suite is decided by the house, not by the brochure. Toronto homes run from 1890s brick semis with balloon framing and knob-and-tube remnants, through 1920s detached homes on 25-foot lots, to 1950s bungalows further out. Basements are frequently shallow, floors are rarely level, and joists are often undersized by modern standards. We survey structure, panel capacity and drain material before quoting rather than after demolition.
Narrow lots, laneway access and shared driveways mean material staging and dust control matter more here than anywhere else in the region. We plan delivery windows and street occupation before the first truck arrives.
Permits — Toronto Building
Toronto permits second suites as-of-right in most residential zones under Bill 23, but restricts new entrances on the front façade that make a house read as a duplex — side and rear entrances are usually the workable route. Heritage Conservation Districts and ravine protection add review steps that we check before design.
Legal Basement pricing
- Legalise an existing finished basement$25,000 — $62,000
- Unfinished basement — standard unit$85,000 — $140,000
- Two-bedroom suite with walk-up$140,000 — $220,000
- Complex build$220,000 — $300,000+
- Per square foot — legal suite$90 — $150 / sq ft
Underpinning to gain ceiling height is the single largest cost variable and can add $80,000 or more. We measure your existing height at the lowest duct before quoting so that number is never a surprise.
Neighbourhoods
The Annex · Riverdale · Leslieville · High Park · The Beaches · Danforth · The Junction · Yorkville · Roncesvalles · Trinity Bellwoods
These apply to every legal basement project in Toronto. Toronto Building is the final authority and we confirm each item against your specific property before quoting.
Code feasibility assessment
Before you spend a dollar we measure ceiling height, window openings, joist depth, panel capacity and lot conditions against the Ontario Building Code and your zoning bylaw, and tell you honestly whether the basement qualifies.
Permit drawings & submission
Floor plans, fire separation details, egress and ventilation schedules prepared and submitted to your municipality, with responses to plan-review comments handled by us.
Separate entrance construction
Side or rear entrances, excavated walk-ups, retaining walls, drainage and a compliant landing and stair. Toronto in particular restricts new front-façade entrances that make a house read as a duplex.
Egress windows & window wells
Cutting and enlarging foundation openings, structural lintels, window wells with proper drainage, and a clear opening that meets the code minimum for escape.
Fire separation & alarms
Rated ceiling and wall assemblies between units, self-closing doors, firestopping at every penetration, and interconnected smoke and carbon monoxide alarms across both dwellings.
Full unit build & registration
Kitchen, bathroom, bedrooms, separate laundry, sound insulation, dedicated HVAC and ventilation, ESA inspection, final building inspection and municipal two-unit registration.
Not seeing your question? Call or text (647) 928-3544 — we answer same day, usually within 2 hours.
Toronto Building handles permits for Toronto. Toronto permits second suites as-of-right in most residential zones under Bill 23, but restricts new entrances on the front façade that make a house read as a duplex — side and rear entrances are usually the workable route. Heritage Conservation Districts and ravine protection add review steps that we check before design. We prepare the drawings, submit the application, respond to plan-review comments and call every inspection through to a closed permit, so you are not standing in a queue at City Hall.
We come to you in Toronto, measure on site, and hand back a written line-by-line quote at no cost. Same day, usually within 2 hours response.
Same day, usually within 2 hours· Serving the GTA, Hamilton, Guelph & Kitchener