Updated: April 2025 | bremo.io financial guides
Building Permit Costs for Renovations in Ontario
Building permits are required for many types of home renovations in Ontario — but not all. Knowing which projects need a permit, how much they cost, and what happens if you don't get one is essential planning knowledge for any Ontario homeowner. Here's a complete guide.
Which Renovations Require a Permit in Ontario?
Under Ontario's Building Code Act and the Ontario Building Code (OBC), a building permit is required for most construction, renovation, or demolition work. Here's a breakdown:
Permits Required
- Creating or legalizing a secondary suite or basement apartment
- Adding or modifying electrical panels and circuits (requires both building permit and Electrical Safety Authority permit)
- New plumbing rough-in or relocation of plumbing fixtures
- Structural changes — removing or altering load-bearing walls
- Adding a deck over 600mm (about 24 inches) from grade
- Building or adding to an addition
- Garage conversions
- Installing a new or replacement HVAC system in many municipalities
- Increasing habitable space (finishing a basement)
- Installing or replacing a fireplace or wood stove
Typically No Permit Required
- Cosmetic renovations (painting, flooring, countertops) with no structural or plumbing changes
- Replacing kitchen or bathroom fixtures in the same location (same drain/supply)
- Installing new cabinets without plumbing changes
- Replacing windows in existing frames (no size change)
- Replacing roofing materials (no structural change)
- Fence replacement
- Minor electrical work (replacing outlets, switches, fixtures)
When in doubt, call your municipality's building department before starting work. They can confirm whether a permit is required. This is a free call and can save you significant headaches.
Permit Costs in Ontario Municipalities (2025)
Ontario permit fees are set by each municipality and vary considerably. They're typically based on the estimated construction value of the project:
Toronto (City of Toronto)
- Residential addition: approximately $14.86 per $1,000 of construction value
- Interior alteration: approximately $8.71 per $1,000 of construction value
- Minimum fee: $200–$600 depending on project type
- Secondary suite permit: $850–$2,500 all-in
Ottawa
- Residential alterations: approximately $12–$16 per $1,000 of construction value
- Minimum fee: $200
- Secondary suite: $600–$1,500
Hamilton
- Interior renovations: approximately $12 per $1,000 of construction value
- Minimum fee: $175
Mississauga / Brampton / Markham
- Similar structure to Toronto: $10–$16 per $1,000 of construction value
- Minimum fees: $200–$400
Smaller Cities (London, Windsor, Kingston)
- Generally $10–$14 per $1,000 of construction value
- Lower minimum fees ($150–$300)
Additional Ontario-Specific Fees
Beyond the building permit, some renovations require additional permits or approvals:
- Electrical Safety Authority (ESA) permit: Required for most electrical work; fees start around $135 and increase with scope
- Technical Standards and Safety Authority (TSSA): Required for gas work (furnace, gas stove installation)
- Conservation Authority approvals: If your property is near a water body or flood plain
- Heritage approvals: If your home is designated heritage property
Permit Application Process in Ontario
- Prepare drawings. Most permits require architectural drawings showing the existing and proposed conditions. For complex projects, a licensed designer, architect, or BCIN-registered designer must prepare them.
- Submit application. Many Ontario municipalities accept applications online, by mail, or in person.
- Pay fees. Fees are paid at time of application.
- Wait for review. Review times vary: 10–30 business days for most residential projects; Toronto can take longer.
- Receive permit. Once approved, post the permit on-site before starting work.
- Inspections. The municipality will inspect at key stages (rough-in, framing, final). You must request each inspection — work cannot be covered until inspected.
- Final inspection. Once the final inspection passes, the permit is closed.
Consequences of Building Without a Permit
Serious risks of unpermitted work:
- Order to stop work and pay fines. Municipalities can issue stop work orders and fines up to $50,000 under the Ontario Building Code Act.
- Required to open up completed work. Inspectors may order you to expose framing, electrical, and plumbing for inspection — destroying finished walls and ceilings.
- Insurance complications. If something goes wrong (fire, flooding), your insurer may deny the claim for any work done without a permit.
- Problems on sale. Lawyers and home inspectors routinely check for permits. Unpermitted work must be disclosed and can kill deals or reduce sale prices.
- Liability for injuries. If someone is injured because of unpermitted unsafe work, you face significant liability.
Tips to Streamline Your Permit Process
- Hire a contractor who handles permit applications (most experienced GCs do)
- Use a BCIN-certified designer for drawings — this is required for many permit applications
- Apply early — permits take time, and starting without one creates legal risk
- Keep copies of all permits, inspection reports, and approvals for future reference