Do you need a building permit to replace a garage door?

City of Hamilton

Hamilton publishes both a list of work that requires a permit and a list of projects that do not. Garage doors are not named on either list in those words, but two entries settle it.

On the list of work that requires a permit, Hamilton names "creating new door or window openings or increasing the size of openings" and "relocating door or window openings". On the list of projects that do not require a building permit, Hamilton names "Replacing existing windows to the same size and location where no fire resistance rating is required".

So: swapping a garage door into the opening it already occupies is not on the permit list. Widening the opening for a bigger door, raising the header, or cutting a new opening in the wall is, because that is structural work on an exterior wall.

Source: City of Hamilton, Building Permit Application Requirements, sections on work requiring a permit and "Projects that Don't Require a Building Permit". Checked 31 August 2026.

Building a detached garage at the same time? Hamilton exempts a detached accessory structure such as a garage, carport or gazebo where it is accessory to a detached house, semi-detached house or row house, provided it is not more than 15 square metres, not more than one storey, and has no plumbing. Above that size, it needs a permit.

Building without one is expensive. Hamilton states that penalties under Section 36 of the Building Code Act carry maximum fines of $50,000 for an individual, or $500,000 for a corporation, for a first offence, along with orders to comply that can be registered on title.

Who to call: Hamilton's Building Division, 905-546-2720. For zoning questions such as setbacks and lot coverage on a new detached garage, the Planning Division is 905-546-2424 ext. 2719.

City of Burlington

Burlington is the clearest municipality in this area on the question, because it names doors explicitly. Its position is that "All construction projects related to a building and or structure require a building permit under the Building Code Act, except in specific cases", and then lists the exceptions. One of those exceptions is, word for word:

"Replacing doors or windows in an existing opening in a house, or in an accessory building serving the house."

City of Burlington, Do I Need a Building Permit?

Source: City of Burlington, Do I Need a Building Permit?, "What projects DO NOT need a building permit?". Checked 31 August 2026.

Burlington also exempts accessory detached buildings for a house, including garages and carports, that are no higher than one storey, less than 15 square metres (161 square feet) in gross area, and have no plumbing.

Who to call: Burlington's Building Department, 905-335-7731, which the city gives specifically for checking whether a building permit is required. General enquiries go to Service Burlington on 905-335-7777.

Town of Grimsby

Grimsby does not publish an exemption list in the same format. Its Building Division categorises projects as residential, I.C.I. and agricultural, and as of 2026 handles applications through the Cloudpermit online system. For a question about a specific project, the town asks you to email building@grimsby.ca or call and ask to speak with a Building Technician.

Source: Town of Grimsby, Applying For a Building Permit. Checked 31 August 2026.

Who to call: Town of Grimsby Building Division, 905-309-2022, or building@grimsby.ca.

Lincoln, St. Catharines and elsewhere in Niagara

We serve Beamsville, Vineland and Jordan in the Town of Lincoln, and St. Catharines and the wider Niagara region. Neither municipality publishes its exemption list at a stable address we are willing to quote from here, so rather than paraphrase a rule we cannot cite, the honest advice is to call your own municipality's building department and ask the same two questions: is a like-for-like garage door replacement exempt, and what is required if the opening changes size.

The overlay that catches people out on the escarpment

Parts of Ancaster, Dundas, Waterdown, Grimsby, Beamsville and the Niagara bench sit on land where a second approval applies before a building permit can be issued. Hamilton names the relevant bodies directly: the Niagara Escarpment Commission, where a Development Permit is required to develop the property, and the local conservation authority where a property has a natural feature on or near it.

Contacts Hamilton publishes: Niagara Escarpment Commission 905-877-5191, Hamilton Conservation Authority 905-525-2181, Conservation Halton 905-336-1158, Niagara Peninsula Conservation Authority 905-788-3135, Grand River Conservation Authority 519-621-2761.

Source: City of Hamilton, Building Permit Application Requirements, sections on conservation authority and Niagara Escarpment Commission lands. Checked 31 August 2026.

None of this applies to swapping a door into an existing opening. It applies if you are building or enlarging a garage, and it is the reason a project on an escarpment lot takes longer than the same project two streets away.

Where a permit is genuinely needed on a garage door job

• Widening or heightening the opening. Going from a single to a double, or raising the header for a taller door, means structural work on a load-bearing wall.
• Cutting a new opening in a garage wall.
• Relocating the opening along the wall.
• Converting the garage to living space, or the reverse.
• Building or enlarging the garage itself beyond the exempt sizes above.
• Rebuilding a fire-damaged garage, which Hamilton lists as permit work in its own right.

Where an opening does change size, the door is the last item on that job, not the first. The framing, the header and the inspection come first, and we schedule the door for after the structural work is signed off.

Two questions worth asking whoever quotes you

1. "Is this opening staying exactly the same size?" If a contractor proposes to widen an opening and does not mention a permit, that is worth a second opinion.
2. "Will you put in writing that no permit is required for this work?" A company that will not is telling you something.