When does widening a garage door opening make sense?
Many GTA garages were built with 8-ft single openings sized for narrower vehicles than today's trucks and SUVs. A modern pickup or 3-row SUV, with mirrors, can leave only inches of clearance in an original 8-ft opening. Widening the opening removes that guesswork.
Curious whether your vehicle actually clears your current opening? The homepage has a vehicle-fit checker that shows clearance by make and model, so you can see the problem, not just guess at it. Homeowners also widen an opening ahead of a sale, when a single door is failing structurally anyway, or simply to park two vehicles side by side instead of nose to tail.
The structural reality: a wider span needs a bigger beam
Bending demand on a header does not scale evenly with width. It rises roughly with the square of the span. Take an 8-ft opening out to a 16-ft-plus opening and the header needs to resist on the order of four times the bending demand, before a room above adds any weight of its own. That is why widening an opening almost always means swapping the original header for an engineered beam sized by a structural engineer, not just cutting a bigger hole in the wall.
The widening process, step by step
Every opening we widen, whether it is two single doors becoming one double or a smaller stretch of an existing opening, follows the same fixed sequence:
- Site assessment. We inspect the existing opening, the header, and what sits above it to determine how much wider the span can safely go.
- Structural engineering. A licensed structural engineer calculates the new span and produces stamped drawings for the beam that will carry it.
- Permit application. We submit the building permit application to your municipality along with the stamped engineering drawings.
- Opening removed under temporary support. A temporary support wall holds the load while the old header, and any centre post, comes out.
- New beam installed. The engineered beam goes in across the full new span, sized and installed to the stamped drawings.
- Rough opening framed. The opening is framed out to the new width, ready for the door.
- Exterior refinished. Brick, stucco, siding, or stone is rebuilt around the wider opening to match the existing facade.
- Door and opener installed. The new door, sized to the wider opening, goes in with an opener matched to its weight.
What does it cost to widen a garage door opening?
Three things drive the price: how much wider the opening gets, what sits above it, and the exterior material that has to be rebuilt around the new opening. A bedroom above the opening means a bigger, redesigned beam. Brick costs more to match than siding or stucco.
$16,000 – $18,000
CAD, all-in · combining two single doors into one wide opening · bump-out or detached garage · nothing load-bearing above the opening
That is the most common version of this job in the GTA. A room above the opening changes the beam design and is priced at a free assessment. Smaller widenings, such as stretching a single opening by a foot or two, follow the same process at a smaller scale and are priced individually once we have seen the structure; span, header type, and finish vary too much to quote a number blind. Full cost breakdown on the cost guide.
Permits in Ontario
Any time the header changes or the opening gets wider, that is structural work and requires a municipal building permit under the Ontario Building Code. Stamped structural engineering drawings are filed alongside the application. Swapping an existing door for a new one in the same opening, with no structural change, does not need a permit.
Fees and timelines vary by municipality. See the full municipal permit breakdown for current Toronto, Mississauga, Vaughan, and Brampton figures. Unpermitted structural work risks stop-work orders, resale disclosure problems, and insurance complications; every project we run is permitted and inspected.
Sixty seconds tells you if your opening can widen
Candidate status first, contact details after. Nothing to lose but the post.
Related reading
If the post between your two doors is the thing standing in the way, see centre post removal for what that involves on its own. If there is living space above your garage, see room above the garage for how that changes the beam design, not the feasibility.
Widening questions, answered plainly
Can you widen an existing garage door opening?
Yes. Widening means removing or replacing the header above the opening with an engineered beam sized for the new span, then reframing and refinishing around it. It's structural work, not a simple door swap, and it requires a municipal building permit in Ontario. .
How much does it cost to widen a garage door opening?
It depends on the span, what's above the opening, and the exterior finish. The most common version, combining two single doors into one wide double opening, runs $16,000 to $18,000 CAD all-in where nothing load-bearing sits above the opening; a room above is priced at a free assessment. Smaller widenings are priced individually once we've assessed the structure. .
Do I need a permit to widen a garage door opening in Ontario?
Yes. Changing the header or widening the opening is structural work and requires a building permit under the Ontario Building Code, with stamped engineering drawings. A like-for-like door replacement in the same opening does not need a permit. .
Can a DIYer widen a garage door opening?
We wouldn't recommend it. The header above a garage door usually carries roof load, and often floor load from a room above, so resizing it is structural work, not a weekend project. Ontario's permit process requires stamped engineering drawings from a licensed structural engineer, which puts the design step out of DIY reach before the framing and finishing even begin. .
How wide can a garage door opening go?
It depends on what the engineer's beam design allows for your specific structure, not a fixed ceiling. In the GTA, the most common outcome is combining two 8-ft single openings into one opening in the 16 to 18-ft range, wide enough for a custom double door. Wider spans are possible; they call for a larger beam and are confirmed at the structural assessment. .
Is widening a garage door opening the same as converting two doors into one?
Converting two single garage doors into one wide double door is the most common way homeowners widen a garage opening in the GTA, but widening also covers smaller jobs, like stretching a single opening by a foot or two for a wider vehicle. Both are structural work with the same engineered-beam-and-permit process; only the scale changes. .
Ready to widen your garage door opening?
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Prefer to talk? Call or text (416) 555-0000.