Independent city
Westmount: restore or replace like-for-like and skip Council review
Westmount issues its own permits, runs its own heritage review, and most of its homes were built in 1960 or earlier. Exterior work on windows and doors falls under its SPAIP by-law, number 1305, and needs City Council's approval, with two exceptions: restoring the original components, and replacing them with identical ones. That makes the old window worth a careful look before a new one is ordered. We match you with an independent local professional who restores or replaces windows. The pro quotes, does the work and can help assemble what the City asks for.
At a glance
- Permits from
- The City of Westmount, not a Montréal borough
- Design review
- SPAIP by-law 1305, approved by City Council
- Outside the review
- Restoration and identical replacement
- Housing
- Mostly pre-1961 houses, plus many apartment buildings
An old, independent city
Westmount grew out of the Village of Côte St-Antoine, incorporated in 1874. It was folded into Montréal as a borough in the 2002 mergers and is again an independent city, with its own Permits and Inspections Division. The window rules on montreal.ca don't apply here.
Most of Westmount's homes were built in 1960 or earlier, and a sizeable share are in apartment buildings of five storeys or more. Both matter for windows. A brick or stone house may still have original wood sash worth saving, while an apartment building brings co-owners, a management office and shared façades into any change. English is the first official language for most residents, and requests in either language are welcome.
By-law 1305 and Council approval
Exterior projects on windows and doors in Westmount are subject to by-law 1305, the City's site planning and architectural integration programme, known as SPAIP. Any such project that isn't a restoration or an identical replacement goes to City Council for approval, on top of the permit or authorization certificate for the work.
The City's own wording sets the tone: on heritage buildings, most work on characteristic exterior elements only allows restoration, or changes that bring them back to their original condition. Read the City's windows and doors page before choosing a product. If the change you want needs Council's approval, build that time into your plans and order nothing until you have the answer.
Restoration and like-for-like replacement: outside the review
This is the practical core of Westmount's approach. Restoring what's there, and replacing a component with an identical one, are the two paths that don't go to Council. For an owner, that turns a design question into a repair question: what exactly is wrong with this window?
The answer is sometimes smaller than it looks. A sash that sticks may need its weatherstripping or balances renewed. A broken crank, latch or sash cord is a part. A cracked pane can be reglazed in the original frame. Where a window truly can't be saved, an identical replacement has to match the original's profiles, material and divisions, which is precise work, so ask the pro directly how they would reproduce yours. Our guide to repairing or replacing windows helps you judge which case you're in.
The inventory of pre-1940 buildings
On 8 September 2025, Westmount adopted an inventory of pre-1940 buildings with heritage value, prepared with the agglomeration under Quebec's Cultural Heritage Act. If your building predates 1940, check whether it is listed before planning any exterior change.
Being listed doesn't mean nothing can be done. It means the rules for heritage buildings, which favour restoration, are the ones to plan around, and that a pro used to repairing older wood windows is the right first call.
The file: shop drawings, numbered photos and a lintel detail
For a permit or authorization certificate for windows or doors, Westmount asks for:
- manufacturer's shop drawings showing the profiles of the new product;
- numbered photos of the existing windows or doors;
- a letter from the association of co-owners, if the building is held in co-ownership.
Widening an opening goes further. The City asks for a lintel detail stamped by a structural engineer, because the wall above the opening has to be carried differently, and a wider opening is neither a restoration nor an identical replacement. The pro we connect you with can supply the shop drawings and photos; the engineer is a separate professional. Our permit guide explains how Westmount's process differs from the Montréal boroughs next door.
Westmount questions
Do I need Council approval to change windows in Westmount?
Only if the work goes beyond restoration or identical replacement. Exterior projects under by-law 1305 need City Council's approval, but restoring original components and replacing them with identical ones are excluded from that review. The work itself may still need a permit or authorization certificate, so ask the Permits and Inspections Division what applies before you book.
Is my building on Westmount's heritage inventory?
If it was built before 1940, it may be. The inventory adopted in September 2025 lists pre-1940 buildings with heritage value, and the City publishes it with the announcement. If yours is listed, plan around restoring the original windows and doors, and expect the City to look closely at anything else. Our guide to repairing or replacing windows helps you weigh the options.
What documents does a Westmount window permit need?
Manufacturer's shop drawings showing the product's profiles, numbered photos of the existing windows or doors, and, for a building held in co-ownership, a letter from the association of co-owners. Widening an opening also needs a lintel detail stamped by a structural engineer. The pro we match you with can usually supply the drawings and photos. Check the City's page for any update before you apply.
Can I enlarge a window opening in Westmount?
You can apply, but it's the longest route. A wider opening isn't a restoration or an identical replacement, so it goes through the SPAIP review with Council approval, and the City asks for a lintel detail stamped by a structural engineer. Talk to the City's urban planning staff before paying for drawings. If the aim is more light, ask the pro whether restoring the existing window gets you most of the way.
Can original stained glass be repaired in Westmount?
Restoration is possible and it's the approach Westmount's rules favour, but it's specialist work. Leaded and stained glass is taken apart, cleaned, re-leaded where needed and reset, and not every glass pro does it. Say clearly on your request that the glass is leaded or stained, with a photo, so it goes to someone who takes on that kind of job. If no one available does, we'll tell you.