Many GTA decks need a building permit, and the line that triggers one is not the same in every city. Toronto Building warns that work done without a required permit can lead to delays, legal action or removal of the work. Here is how it works under Ontario’s 2024 Building Code, in force since January 1, 2025, and how Toronto, Vaughan and Mississauga apply it.
When a deck needs a permit
Two things decide it: how high the deck sits above the ground and whether it is attached to the house. Each municipality publishes its own threshold, and they differ.
- Toronto: a permit is required for a deck more than 60 cm (24 in) above the ground. A lower, uncovered platform can go without one if it is not part of a required exit and meets the zoning by-law.
- Vaughan: any deck or porch attached to a building needs a permit, whatever its size or height. A detached, uncovered deck is exempt only if it is no more than 18.6 m² (about 200 sq ft) and no more than 0.6 m above grade.
- Mississauga: a permit is required for a deck more than 0.61 m (2 ft) high, and for any covered porch.
- Richmond Hill: a permit is required if the deck is attached to the house, more than 600 mm above average grade, or larger than 10 m² (108 sq ft).
No permit does not mean no rules. Every deck still has to meet the zoning by-law, which controls how close it can come to your property lines and, on many lots, how much of the lot it can cover. Lots near ravines or watercourses may also need Toronto and Region Conservation Authority approval before a permit is issued.
What the permit drawings have to show
Toronto and Vaughan both ask for scaled, fully dimensioned drawings, signed, dated and submitted as PDFs. Between the two cities’ checklists, a complete deck package includes:
- A survey or site plan with the deck drawn in and its distances to the property lines.
- A foundation plan with footing size, spacing and depth, and how the footings are protected from frost.
- A framing plan with the size, spacing and span of posts, beams and joists, and the material of each.
- Side views and a cross-section showing deck height, guard height and the connection to the house.
- Stair details (riser height, tread depth, headroom) and guard details, including openings and how the guard resists climbing.
- Designer information. A homeowner may prepare their own drawings. A designer must show their name, BCIN and signature, and in Toronto an engineer who seals drawings also files an Assumption of Responsibility form.
Toronto’s 2026 permit fee for a residential deck or porch is $214.79, and applications go through Toronto Building’s online portal. If you plan glass or aluminum railings, include the manufacturer’s engineered guard details. Vaughan lists them as a drawing requirement.
What the inspector checks
Once the permit is issued, you call for inspections at set stages. Toronto books them within two business days of your request and expects the stamped permit drawings on site. Anything covered before it passes has to be opened up again. Before footing holes are dug, a locate request has to go to Ontario Dig Authority (formerly Ontario One Call) so buried utility lines are marked. On a typical wood deck, the inspector focuses on four things.
- Footings, before any concrete is poured. Vaughan wants the forms on undisturbed soil, with no frost, standing water or loose material in the hole. Richmond Hill’s checklist sets a minimum depth of 1.2 m (4 ft) below grade.
- Attachment to the house. Richmond Hill’s checklist notes that the Building Code does not allow a deck to be attached to brick veneer, so the load has to go into the house’s structure or foundation wall, or the deck stands on its own posts and beam.
- Height and guards. The code requires a guard where the walking surface is more than 600 mm above the ground within 1.2 m of its edge. On a house, the guard must be at least 900 mm high where the deck is no more than 1.8 m above finished ground, and at least 1 070 mm where it is higher. Openings must stop a 100 mm sphere, and nothing between 140 mm and 900 mm above the deck may make the guard climbable.
- The finished deck. At the final inspection, stairs, guards and handrails are complete and the grading is done.
For composite boards and plastic guards, building departments look for an evaluation from the Canadian Construction Materials Centre (CCMC). Richmond Hill does not accept plastic guards without one. Since July 2025, Ontario no longer requires a separate Minister’s ruling for CCMC-evaluated products, so the CCMC evaluation is the document to keep in your permit file.
When the final inspection passes, confirm the permit is closed. Toronto Building notes that open permits can hold up a future sale and complicate later permit applications.
How MKC handles deck permits
At MKC Group, our in-house engineering department prepares the deck drawings and any engineering letters, we submit the permit application, and our crews build to the approved plans. We install composite decking from TimberTech, Trex and TIVADEK. For a deck in Toronto, Vaughan, Mississauga or elsewhere in the GTA, call (647) 637-6052 for a free estimate.