Do you need a permit for a deck in Montreal or Laval?
In short
In Montreal, building, enlarging or replacing a deck, balcony or gallery almost always needs a permit from the borough; upkeep and repairs generally don’t. In Laval, a residential deck needs no permit in most cases, except in a PIIA zone, but a balcony at the front of the house does.
By the DV Groupe team · Updated · 3 min read
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Montreal and Laval side by side
Montreal
Upkeep and repairs: generally no permit
Build, enlarge, modify or replace: permit required, with rare exceptions
Standards are set by the borough: distances, floor height, railings, materials
Materials different from the original: tell the permit desk before buying
Laval
Residential deck: no permit in most cases, but the urban planning code applies
Permit required if the property is subject to a PIIA
Balcony, gallery, landing or porch in a front or side yard or facing a street: permit required
In the backyard: upkeep and repairs generally need no permit
City of Montreal (page updated February 11, 2026) and City of Laval, consulted October 6, 2026. Rules change: check before the work starts.
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Before the work starts
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Call the right office
In Montreal, the permit desk of the borough where the work happens; in Laval, the urban planning department (Service de l’urbanisme).
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Check for special zones
In Montreal, some areas or buildings have heritage value and stricter standards; in Laval, check whether the property is subject to a PIIA (architectural integration plan).
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Allow for the delay
Laval quotes about 30 days for a residential balcony or gallery permit, counted from the moment every document has been received.
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Ask for the RBQ licence
Laval’s permit application form asks for the RBQ licence of the contractor doing the work.
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What about the RBQ licence?
According to CAA-Québec, building a deck that isn’t attached to the house generally needs no licence, but a licence from the Régie du bâtiment du Québec is required as soon as elements are attached to the building. Before signing a contract, look the contractor up in the RBQ licence holder registry and make sure the number is valid.
DV Groupe builds new decks and rebuilds old ones, from the structure to the finish. See deck building, or compare materials in Composite or wood deck?.
Common questions
Do you need a permit to repair a deck in Montreal?
In most cases, no: upkeep and repairs don’t require one. If you change the materials from the original, the City asks you to tell the permit desk before buying, with a professional-quality plan.
Do you need a permit for a deck in Laval?
In most cases, no, according to the City of Laval, but the deck must follow the urban planning code, and a permit is required if the property is subject to a PIIA.
How long does a permit take in Laval?
The City of Laval quotes about 30 days for a residential permit, an approximate delay that starts once every required document has been received.
Who applies for the permit?
The owner, or someone acting for them. In Laval, the form allows another person to file the application, with a power of attorney attached.
