Turning your basement into a bedroom, a legal apartment or a home office? You need a code-compliant egress window — and in most older homes, that means enlarging the existing opening or cutting a brand-new one through the foundation. That's exactly what we do: we saw-cut the concrete with a wall saw, cleanly, without hammering your foundation. We work on both sides of the river and know the requirements on each.
What the code requires
In Ontario it's the Ontario Building Code (OBC); in Quebec, the Code de construction du Québec. Either way, a basement bedroom egress window must provide:
- An unobstructed opening of at least 0.35 m² (3.8 ft²) with the window open
- No dimension under 380 mm (15 in) — neither height nor width
- A window well with at least 550 mm of clearance in front of the window, so a person can actually climb out
- The window must open from the inside without tools or keys
A standard 24 in × 12 in basement window doesn't come close. The opening usually has to grow downward and wider. For the full rundown, read our article on enlarging a basement window to code.
How we cut the opening
- Layout of the new opening and a check for what's inside the wall (pipes, wiring, drain tile)
- Wall-saw cutting with a diamond blade, full depth through the foundation — no jackhammer against your foundation, no stress cracks
- Block removal in manageable pieces, often core-drilled at the corners for perfectly square corners
- Clean, square edges ready for framing and the new window
A typical opening is cut in one day. Window, well and drainage installation are handled by your contractor or window installer afterwards.
Who this is for
The typical client is someone adding a basement bedroom for a teenager, a parent or a tenant — or legalizing a secondary suite to collect rental income properly. Without a compliant egress window, that basement bedroom isn't legal, your insurance can walk away from a claim, and you'll get stopped at inspection when you sell. It's also the escape route that saves lives in a fire. Cutting the opening is step one — and it's the step you can't afford to get wrong, because a foundation doesn't forgive blind cuts.
A real job site: legal apartment in Ottawa
A common project: a duplex in Ottawa where the owner wanted to legalize a basement unit. Two bedrooms meant two brand-new egress openings in a block foundation. We cut both openings in a single day, the window crew was in the next morning, and the place passed inspection on the first visit.
One tip: book your building permit before you book us. Municipalities on both sides of the river want a permit for a new basement bedroom or secondary suite, and the inspector will measure the opening. We cut to the code dimensions, so the measurements pass.
Cutting the foundation wall
Cutting in progressCutting an egress window opening typically runs $1,200 to $2,500, depending on opening size, foundation thickness and type (poured concrete, block, stone) and exterior access. The window, well and finishing are not included.
Frequently asked questions
What size does an egress window have to be?
The Ontario Building Code and the Quebec Construction Code both set a minimum opening area and a minimum dimension in each direction. The exact figures for both codes are detailed here →
What does an egress window cost in total?
There are three parts: cutting the concrete, the excavation and window well, then the window itself and its installation. We break down each part here →
Do you also do the excavation and window well?
Our part is cutting the concrete — the part few contractors can do cleanly. For the excavation, the well and the installation, we refer you to local contractors we work with regularly.
Can this be done in winter?
Cutting the concrete, yes, in any season. Outdoor excavation depends on frost. Here is what can and cannot be done in winter →