Window replacement in Montréal: permits and rebates

Good windows make the house more comfortable and cut heat loss. But a poorly installed window loses much of its value: the installation matters as much as the product, and in many Greater Montréal neighbourhoods the look of the façade is regulated too.

1. When to replace your windows

• Fog or condensation between the two panes: the sealed unit has failed.
• Drafts even with weatherstripping in good shape.
• Rotten or swollen frames, or windows that do not close properly.

Sometimes only the sealed unit, the hardware or the weatherstripping needs changing: ask whether a repair is enough before replacing the whole window. For drafts, see also caulking and weatherstripping.

2. What the quote must specify

• The model, the frame material (PVC, hybrid, aluminum, wood) and the glazing, and whether the windows are ENERGY STAR certified.
• The installation method: insulation and sealing around the frame, flashing, exterior caulking.
• Interior and exterior finishing (trim, cladding, sill).
• Disposal of the old windows.
• The warranties: the manufacturer’s on the product and the contractor’s on the installation.
• Who applies for the permit, if one is needed.

In each bedroom, keep at least one window that opens wide enough to get out in an emergency: the City of Montréal (in French) reminds owners that bedroom windows must meet egress requirements.

3. Windows in Montréal and Laval: when you need a permit

• Montréal: according to the page on replacing doors and windows with same-size models (in French, updated July 30, 2026), the rule depends on the borough: several generally require no permit for a same-size replacement, others require one for any replacement. Changing the size needs a permit, and in heritage sectors the new units must keep the original shape and appearance.
• Le Sud-Ouest: the same page says a PVC exterior finish on windows, frame included, is prohibited throughout the borough (a hybrid model is still possible), and that windows serving a dwelling must be ENERGY STAR certified.
• Laval: replacing doors and windows with the same dimensions needs no permit; changing their size, adding new ones, or replacing a window less than 1.5 m (5 ft) from the property line does (exterior home renovation, in French).
• Saint-Eustache: same-size doors and windows need no permit, except in Vieux Saint-Eustache or for a classified or cited heritage building (permits and certificates, in French).

4. The installer’s licence

Installing doors and windows falls under RBQ subclass 8 (architectural openings). Check the licence of the company that installs the windows, not just the manufacturer or the store that sells them.

5. The Rénoclimat rebate since October 2026

The Québec government’s Rénoclimat program was simplified on October 1, 2026. According to its page on what is new (in French, updated October 13, 2026, read November 1, 2026), window replacement can qualify for up to $4,500 for a single-family house, that is $300 per window, and up to $6,000 for a duplex, a triplex or a multi-unit residential building. The pre-work energy evaluation is now recommended rather than mandatory, the contractor must hold the appropriate licences and sign a compliance form, and the application portal was still being built. Keep the quote, the invoice and the product sheets.

To find a company, browse renovation in Le Sud-Ouest or in Saint-Eustache, the Laval page, or describe your windows and get quotes.