Deck Permit Requirements in Ontario
Last updated: June 2026
When a building permit is required for deck construction or replacement.
Detailed explanation
Many municipalities require a building permit for new decks, structural changes, or decks above a certain height. The OBC sets construction standards; the local building department determines permit triggers.
Decks attached to a dwelling typically require permits because they affect structural loads, guards, and egress. Floating or low-grade platforms may be exempt in some jurisdictions — always verify locally.
Permit applications usually require drawings showing footing size, beam and joist spans, guard details, and connection to the house.
Ontario Building Code references
Ontario Building Code
Section 9.4.2. — Structural protection
Structural requirements for building elements.
Ontario Building Code
Section 9.8.8. — Guards
Guard requirements for elevated decks.
Examples
- A raised deck attached to a second-floor door almost always requires a permit.
- Replacing deck boards only may not require a permit; replacing joists or guards usually does.
Common mistakes
- Assuming no permit is needed because the deck is small.
- Submitting incomplete guard or footing details on permit drawings.
- Starting construction before permit issuance and inspection milestones.
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