Do you need a permit for a shed in Mississauga, Toronto or Oakville?

Not for most backyard storage sheds. In Mississauga, Toronto and Oakville, a detached shed used for storage, smaller than 15 m² (about 161 sq ft) and without plumbing, generally doesn't need a building permit. Reaching 15 m², adding plumbing, attaching the shed to the house or using it for something other than storage can change the answer. Zoning rules apply in every case.

The summaries below come from each city's published guidance. Rules are updated from time to time, so confirm with your municipality before you order materials or book a build.

The 15 m² rule, city by city

Notice what happens at exactly 15 m². Mississauga and Brampton require a permit at 15 m² or more, while Vaughan's exemption runs up to and including 15 m². The safe approach is to design a shed that sits clearly under the line, not on it.

Worked examples

Here is how three common sizes compare. One square metre is about 10.76 sq ft.

• 10×12 ft: 120 sq ft, about 11.1 m². Comfortably under 15 m². As a detached storage shed with no plumbing, it generally needs no permit in any of the five cities. Use the same building as a cabana, pool change room or workshop, though, and it's over the 10 m² line Toronto and Brampton apply to those uses.
• 10×16 ft: 160 sq ft, about 14.9 m². Just under 15 m², so a storage-only shed with no plumbing generally fits the exemption. There's almost no margin. Before you build at this size, ask the building department how it measures a shed's area, and check that your plans stay under 15 m² on that basis.
• 12×16 ft: 192 sq ft, about 17.8 m². Over 15 m². Plan on a building permit in Mississauga, Toronto, Oakville, Brampton and Vaughan.

Plumbing, power and attached sheds

• Plumbing. A sink or washroom generally means a permit at any size. Ontario's Building Code Act counts even a structure of 10 m² or less as a building if it contains plumbing, and Mississauga, Toronto, Oakville and Vaughan all name plumbing as a trigger.
• Attached to the house. Toronto requires a permit for an accessory structure attached to a building, and Vaughan's exemption covers only detached sheds. A lean-to built against the house is a different project from a freestanding shed.
• Power. Electrical work is a separate approval. In Ontario, electrical work done for hire must be carried out by a Licensed Electrical Contractor, who files the notification with the Electrical Safety Authority (ESA).

Cabanas, pool sheds and other accessory buildings

The 15 m² exemption is aimed at sheds used for storage. Buildings with other uses can be treated differently:

• Toronto applies a 10 m² threshold to garages, cabanas, workshops and similar accessory buildings.
• Brampton requires a permit for gazebos, cabanas and pool change rooms of 10 m² or more.
• Mississauga lists gazebos of 10 m² or less as not needing a permit.
• Oakville's exemption treats sheds, cabanas and gazebos alike, as long as they're under 15 m² with no plumbing.

That makes a pool shed worth a closer look. If it holds chairs, toys and cleaning gear, it's storage. If people will change in it, it may be a cabana or change room, so describe it that way when you ask the city.

Zoning applies even without a permit

A shed that's exempt from a building permit still has to meet your zoning by-law. Depending on your city and lot, zoning controls things like:

• how far the shed must sit from your property lines
• its maximum height
• how much of the lot buildings can cover
• which yard it's allowed in

Vaughan's guidance says this plainly: setbacks and lot coverage still apply to exempt sheds. The numbers vary by municipality and by zone, so look up your property's zoning or ask the city before you choose a spot. A shed that blocks drainage or sits tight against a shared fence can also cause friction with a neighbour, even when it's legal.

If your shed needs a permit

A larger shed, or one with plumbing, goes through the same process as other small buildings. Expect to submit a site plan showing where the shed sits and how far it is from your lot lines, along with drawings that show how it will be built. Mississauga publishes lists of the drawings and documents it needs by project type, which is a good place to start. Inspections follow once the permit is issued.

What our custom sheds cost

We build sheds on site, from storage and pool sheds to larger workshops, with real windows and doors. Planning prices, plus HST:

• Wood shed with windows: $10,000–$15,000
• 10×16 shed in premium materials: $18,000–$24,000
• Brick or stucco finish: $35,000+

As examples from real jobs, a wood pool shed with two windows came to about $12,000, a 10×16 shed in premium materials to about $20,000, and a shed with a brick or stucco finish to about $35,000, all plus HST. Size, siding and roofing, windows and doors, masonry finishes and electrical work all move the price. These are planning figures, not quotes. Your price comes from a site visit.

Planning a shed?

See our custom shed service, compare figures on our pricing page, or book a free on-site estimate anywhere in Mississauga, Toronto, Oakville or the GTA. If you have a survey of your lot, have it handy: it makes setbacks much easier to check.