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Do I need a building permit? (GTA)
Check whether a home project likely needs a building permit in 12 GTA municipalities, with the city’s rule and a link to its own page. ✓ Rules checked Oct 10, 2026
Same project in all 12 municipalities
How the building permit checker works
Under section 8 of Ontario’s Building Code Act you need a permit to construct, materially alter or demolish a building. The Ontario Building Code (O. Reg. 163/24, Division C, Article 1.3.1.1) exempts only a few things province-wide — most usefully a shed of not more than 15 m² that is one storey, detached, used only for storage ancillary to the house, and has no plumbing. Everything else (decks, gazebos, fences, small renovations) depends on each municipality’s published lists, which differ — e.g. an 18 m² low detached deck is exempt in Vaughan but needs a permit in Richmond Hill.
This tool paraphrases each city’s own “do I need a permit” pages. Likely yes / likely no = the city states it. Depends = the rule turns on details (or the city’s pages conflict). Check = we could not find a published rule, so we don’t guess. A permit-free project must still meet zoning (setbacks, height, lot coverage), fence/pool by-laws, conservation-authority, heritage and Electrical Safety Authority rules. Always call the city to confirm before you build.
Do I need a building permit? (GTA): frequently asked questions
Do I need a permit for a shed under 15 m² anywhere in Ontario?
Generally no — OBC Div. C 1.3.1.1.(6) exempts a shed of not more than 15 m² that is one storey, not attached, used only for storage and has no plumbing. Zoning still applies, and many cities use a 10 m² limit for other accessory buildings like gazebos and cabanas.
Is a basement apartment (ARU) legal without a permit?
No. Creating a second dwelling unit needs a building permit, and Brampton also requires two-unit dwelling registration.
Do I need a permit to replace my furnace?
Most GTA cities exempt a like-for-like furnace replacement with no duct changes. Mississauga is an exception: a higher-efficiency replacement or any duct alteration needs a permit.
What about electrical work?
Building permits don’t cover electrical work; it is inspected by the Electrical Safety Authority (ESA).
Why does it say “check with the city”?
Because that city does not publish a rule for that project on the pages we reviewed. We never fill gaps with guesses — call the building department.
Is this legal advice?
No. It is a plain-language summary of official pages as of Oct 10, 2026. The city’s Chief Building Official has the final say.
Official sources
- Ontario Building Code, O. Reg. 163/24 (Div. C 1.3.1.1 exemptions)
- Building Code Act, 1992 (s. 8 permits)
- Toronto — When do I need a building permit?
- Mississauga — When a building permit is required
- Brampton — Home improvement brochure
- Brampton — When a permit is not required
- Brampton — Sheds and accessory structures
- Markham — Building permit process
- Markham — Decks, construction, permits
- Vaughan — Building permits
- Vaughan — Decks and porches
- Richmond Hill — Building permit FAQs
- Richmond Hill — R6 deck checklist (PDF)
- Oakville — Building permits
- Oakville — Decks
- Burlington — Do I need a building permit?
- Burlington — CBO-01 accessory buildings directive (PDF)
- Ajax — Building permits & inspections
- Pickering — Building permits
- Whitby — Building permits
- Whitby — Decks and fences
- Whitby — Accessory structures
- Oshawa — Building permits
- Oshawa — Decks
- Oshawa — Accessory structures
Rules checked Oct 10, 2026. Estimates only — confirm with official sources and a professional.