Permits in Mississauga
When a backyard shed, deck, or fence needs a building permit in Mississauga, Ontario, with the size cut-offs, coverage level, and source link.
Coverage
Municipal rule
Shed
Mississauga is stricter than the provincial baseline: a shed needs a building permit once it is larger than 10 square metres (about 108 square feet), or any size if it has plumbing.
Deck
A deck more than 600 mm (about 2 ft) above grade, or attached to the house, needs a permit. A deck under 600 mm does not.
Fence
Fences need no building permit; the fence bylaw caps height. Pool enclosures need a separate permit.
The provincial baseline
Under the Ontario Building Code, a detached one-storey storage shed of 15 square metres (about 160 square feet) or less, with no plumbing, does not need a building permit. Anything larger, with plumbing, or attached to another building does. Zoning rules (setbacks, height, lot coverage) always apply even when no building permit is needed.
Mississauga permit questions
Do I need a permit to build a shed in Mississauga?
Mississauga is stricter than the provincial baseline: a shed needs a building permit once it is larger than 10 square metres (about 108 square feet), or any size if it has plumbing. Source: Mississauga building department, last checked 2026-06-24.
Do I need a permit for a deck in Mississauga?
A deck more than 600 mm (about 2 ft) above grade, or attached to the house, needs a permit. A deck under 600 mm does not.
Do I need a permit for a fence in Mississauga?
Fences need no building permit; the fence bylaw caps height. Pool enclosures need a separate permit.
Source
From Mississauga building department, last checked 2026-06-24. Worth knowing: Mississauga's 10 square metre shed cut-off is lower than the 15 square metres many people assume from the building code.
This is a plain-language explainer, not legal or professional advice, and not the bylaw itself. Rules change and vary by zone within a city. Always confirm with your municipality's building department and the linked official page before you build. Decks and sheds near a conservation authority's regulated area may need a separate permit.
Other municipalities: Brampton, Caledon, Peel, Regional Municipality of, Addington Highlands. Or see every municipality.