Egress windows come up on almost every basement finishing project we do in Brantford. A homeowner wants to add a bedroom or create a legal rental suite, and at some point the question arises: does this window meet code? The answer is usually no — and understanding why matters before you start framing walls.
This post covers what egress windows are, when Ontario Building Code requires them, and what installation costs look like for Brantford homeowners in 2026.
What is an egress window?
An egress window is a window large enough for an occupant to escape through in a fire emergency. In a basement bedroom, it's the backup exit if the stairway is blocked. The size requirements aren't arbitrary — they're based on the dimensions a person in a panic needs to actually get out, and they're part of the Ontario Building Code.
Most existing basement windows in Brantford homes — the narrow hopper or slider windows installed when the house was built — don't come close to meeting egress requirements. They were designed for light and ventilation, not emergency escape. That's fine for a storage room or utility area. The moment you put a bed in the room and call it a bedroom, the code applies.
What does the Ontario Building Code require?
For any sleeping room below grade, the Ontario Building Code (OBC) requires at least one window that meets all of the following:
- Minimum unobstructed opening area of 0.35 m² (about 3.8 sq ft)
- Minimum unobstructed opening height of 380 mm (15 inches)
- Minimum unobstructed opening width of 380 mm (15 inches)
- Sill height no more than 1,500 mm (about 59 inches) above the finished floor
The "unobstructed opening" part matters. A window might measure larger than that, but if it only opens halfway or has a fixed centre pane, the opening that counts is what you can actually climb through. Screens and window wells don't count against you, but anything that limits the opening does.
Brantford's building department enforces the OBC, so your permit inspector will be measuring. There's no wiggle room on these numbers.
When do you need an egress window in Brantford?
You need a compliant egress window any time you are:
- Adding or legalizing a basement bedroom
- Finishing a basement as a legal secondary suite or ARU
- Converting a storage or utility space into any sleeping room
If you're finishing the basement as a rec room, home office, or gym with no sleeping area, egress windows are not required by code — though they're still a good idea for natural light and resale. The trigger is specifically sleeping occupancy.
For secondary suites, the requirements go further: in addition to egress from each bedroom, the suite itself needs a direct exit to the exterior or a protected corridor. That's a separate conversation from the window itself, but worth knowing before you plan the layout.
What's involved in installing an egress window in Brantford?
Installing an egress window isn't just swapping out a window — it typically involves cutting through the foundation wall to create a larger rough opening. Most Brantford homes have poured concrete or concrete block foundations, both of which require a concrete saw or core drill. The work needs to be done carefully to avoid compromising the structure, and it requires shoring the opening during installation.
Outside the house, you'll also need a window well — a curved steel or concrete enclosure that keeps soil from pressing against the window and allows light and airflow. For windows that sit more than a few inches below grade, a deeper well is required, often with a gravel drainage base and sometimes a cover to keep out leaves and rain.
The full scope of a typical egress window installation in Brantford includes:
- Saw-cutting the foundation wall to the required rough opening size
- Installing a lintel or steel header to carry load above the new opening
- Installing the new egress-compliant window
- Installing the exterior window well and drainage gravel
- Waterproofing and sealing the opening inside and out
- Interior framing, drywall patching, and trim
Egress window installation costs in Brantford
For a single egress window in a standard Brantford home, expect to budget $3,500–$6,500 depending on the depth of excavation required and the foundation type. Poured concrete foundations cost more to cut than block. Deeper wells that require significant exterior excavation add to the total.
| Scenario | Typical cost range |
|---|---|
| Standard installation, poured concrete, window well to 600mm depth | $3,500–$4,500 |
| Deeper excavation required, well over 900mm | $4,500–$6,500 |
| Second egress window (same mobilization) | Add $2,500–$3,500 |
These costs assume a single window as part of a broader basement finishing project. If you're adding egress windows as a standalone job, there will be some additional mobilization cost. When we're already on site for a basement finishing project, the work integrates cleanly into the schedule and we avoid duplicating trades.
Does an egress window require a permit in Brantford?
Yes. Cutting a new opening in a foundation wall is a structural alteration and requires a building permit from the City of Brantford. This is non-negotiable, and it's not the kind of thing you want to skip — foundation openings that aren't properly permitted and inspected create real liability issues when you sell the home. The inspector will verify the opening size, the lintel installation, and the waterproofing before the project closes.
A basement bedroom without a compliant egress window isn't just a code violation — it's a fire safety hazard. When we do basement finishing in Brantford, we treat egress compliance as a baseline, not an optional upgrade.
Planning a basement with an egress window
If you're early in planning a basement bedroom or suite in Brantford, the egress window is one of the first things to nail down — it determines where the bedroom can go and affects the exterior landscaping. We include egress window installation in our basement finishing estimates so there are no surprises once permits are submitted.
If you're not sure whether your existing basement windows meet code, we can check them during our site visit. Often a quick measurement tells us whether we're installing new windows or simply verifying what's already there.
We offer free on-site estimates for basement finishing projects throughout Brantford and Brant County. Get in touch and we'll assess your space, confirm egress requirements, and give you a realistic budget for the full project.
For more on this topic, see our basement finishing services.
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