Foundation Wall Opening Permits: Ottawa vs Gatineau Rules (2026)

2026-08-20 — Ottawa-Gatineau

Good news first: cutting or enlarging an opening in a foundation wall is a perfectly normal project — and the permit is far less painful than most people expect. Whether you're in Ottawa or Gatineau, here's exactly what applies in 2026.

Ottawa: the City of Ottawa building permit

In Ottawa, creating or enlarging an opening in an exterior wall (door, window, egress window) requires a building permit. What you need to know:

• Cost: generally $100 to $300 for a residential project of this size (the fee is based on the declared value of the work).
• Drawings: a simple sketch is often enough — opening location, dimensions, and how the lintel will be supported. For a major structural opening, the City may ask for engineered details.
• Timeline: allow 2 to 6 weeks for approval of a straightforward residential permit, depending on the season.
• Inspection: an inspector verifies the opening and lintel support before you close up the finishes.

Gatineau: the permis de construction / rénovation

Across the river, it's the Ville de Gatineau's building/renovation permit that applies. Same principle:

• Cost: roughly $100 to $250 for a window or door opening in a foundation.
• Documents: application form, a dimensioned sketch of the opening, sometimes a photo of the existing wall. For an egress window, the NBC minimum dimensions should appear on the plan.
• Timeline: often faster than Ottawa — 1 to 3 weeks for a complete, simple file.
• Inspection: the City reserves a visit during or after the work.

In both cities, the homeowner can apply

Inspection: the City reserves a visit during or after the work.

Applications go through the City's urbanisme counter (or online portal), and staff will tell you within days if anything is missing from your file.

In both cities, the homeowner can apply for the permit themselves — you don't need to hire a designer for a simple window opening. Your contractor can also handle it for you.

Your contractor can also handle it for you.

A practical note on timing: neither city requires the permit to be in your hand before you book a contractor — only before the cutting starts. Booking the cut and filing the permit in parallel is the fastest way to get the project done.

When you do NOT need a permit

• Replacing a window at the exact same size, without touching the concrete opening.
• Core-drilled holes for pipes, wires or vents (standard diameters, no structural impact).
• Non-structural interior openings (partitions, non-load-bearing interior walls).

The moment you cut into the foundation wall to enlarge or create an opening, though, the permit applies — on both sides of the river.

What the inspector actually looks at

What the inspector actually looks at

Inspectors see foundation openings every week. They're not looking to trip you up — they want three things: structure, safety, water.

• The lintel: the opening must be properly supported (steel or concrete lintel, or reinforced interior framing, depending on the case).
• Egress dimensions if it's a bedroom: minimum 0.35 m² of clear opening, no dimension under 380 mm.
• Waterproofing: the perimeter of the opening must be sealed against water.
• Match with the approved plan: right location, right size.

In pictures

Hydraulic saw in place
Slab cut into sections
$100 – $300

The typical permit cost for a foundation wall opening, in Ottawa and Gatineau alike. Cheap insurance for a legal file, valid coverage and a surprise-free resale.

Tips for a stress-free process

• Apply BEFORE the cut. Cutting without a permit risks fines, a stop-work order and insurance headaches.
• Keep your paperwork. The permit and inspection report are worth real money at resale.
• Work with a contractor who knows the process. We cut permitted openings every week — we know what inspectors want to see.
• Build the timeline into your schedule. Order the window while the permit is being processed, not after.
• Build the timeline into your schedule. Order the window while the permit is being processed, not after.
• Ask about faster counter service. For very simple residential files, some counters can turn a complete application around well ahead of the standard queue.

Want us to handle the cutting while your permit moves through? See our window & door openings service → — free quote within 24 hours. For required egress dimensions, also read our article on basement window egress code.