Permits in Thunder Bay
When a backyard shed, deck, or fence needs a building permit in Thunder Bay, Ontario, with the size cut-offs, coverage level, and source link.
Coverage
Provincial baseline
Shed
Provincial baseline: a detached one-storey storage shed up to 15 square metres, with no plumbing, does not need a building permit in Ontario. Zoning setbacks, lot coverage, conservation authority rules, and any stricter Thunder Bay rule still apply.
Deck
Provincial baseline: decks can need permits when attached, elevated, structurally complex, or serving an entrance. We have not verified Thunder Bay's local deck page yet, so check the municipal building department before building.
Fence
Provincial baseline: ordinary fences are usually handled by local fence bylaws, not by a province-wide building permit rule. Pool enclosures, corner lots, heights, and sightlines can trigger separate Thunder Bay rules.
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.
Thunder Bay permit questions
Do I need a permit to build a shed in Thunder Bay?
Provincial baseline: a detached one-storey storage shed up to 15 square metres, with no plumbing, does not need a building permit in Ontario. Zoning setbacks, lot coverage, conservation authority rules, and any stricter Thunder Bay rule still apply. Source: Ontario building permits and Building Code baseline, last checked 2026-06-24.
Do I need a permit for a deck in Thunder Bay?
Provincial baseline: decks can need permits when attached, elevated, structurally complex, or serving an entrance. We have not verified Thunder Bay's local deck page yet, so check the municipal building department before building.
Do I need a permit for a fence in Thunder Bay?
Provincial baseline: ordinary fences are usually handled by local fence bylaws, not by a province-wide building permit rule. Pool enclosures, corner lots, heights, and sightlines can trigger separate Thunder Bay rules.
Source
From Ontario building permits and Building Code baseline, last checked 2026-06-24. Thunder Bay is covered by the provincial baseline. Municipal shed, deck, and fence specifics have not been verified yet. Municipal contact point: Thunder Bay.
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: Conmee, Dorion, Gillies, Greenstone. Or see every municipality.