Cost, Ontario Building Code requirements, and what the installation process actually looks like — from a contractor who has done hundreds of them across Toronto and the GTA.
An egress window is not an upgrade. It is a life-safety requirement. The Ontario Building Code mandates that any basement space used as a sleeping area must have at least one window large enough for a person to escape through in an emergency. When you are finishing a basement bedroom, adding a secondary suite, or simply converting an unfinished lower level into livable space, egress compliance is not optional — and in Toronto, a building inspector will check for it.
Beyond code compliance, egress windows change the feel of a basement dramatically. The difference between a basement room with a legal egress window and one with a narrow basement slit is the difference between a space that feels like a real room and one that feels like a storage area with furniture in it. Natural light, fresh air, and the psychological sense of openness matter in below-grade spaces more than anywhere else in the house.
We have installed egress windows in basements across Toronto, North York, Etobicoke, and the surrounding GTA for more than two decades. The process is more involved than most homeowners expect when they first ask about it, but it is entirely manageable with the right contractor and a clear understanding of what is required. This guide covers all of it: the code requirements, the real costs, the permit process, and what installation actually looks like from start to finish.
The Ontario Building Code sets out the minimum dimensions for egress openings in sleeping areas below grade. These are not suggestions — they are hard requirements that will be verified at inspection. Understanding them before you select a window unit is essential, because not every window that looks large enough will actually comply.
The key measurement is the unobstructed openable area — the clear space available when the window is fully open, not the size of the window frame. Under the Ontario Building Code, a basement sleeping room egress window must provide:
These dimensions apply to the clear opening — after the window sash and frame are accounted for. A window with a 400 mm x 900 mm frame may not provide a 0.35 m² opening once the frame width is deducted. When in doubt, check the manufacturer's listed egress dimensions specifically, not the rough opening size.
In most Toronto basements, the window sill will be below or near grade level, which means a window well is required on the exterior. The window well must be large enough to allow the egress opening to function fully. In practice, this means the well needs to extend at least 760 mm (30 inches) from the foundation wall to give a person room to maneuver while exiting, and it must be wide enough that the window can swing or slide fully open without restriction.
If the window well is deeper than 760 mm below grade, the Building Code also requires a permanently installed ladder or step system inside the well, so that once a person exits through the window they can actually climb out of the well to grade level. This is a detail that gets missed frequently on DIY projects and informal contractor work — inspectors check for it.
Secondary suite rules are stricter: If your basement egress window is part of a legal secondary suite (basement apartment), the City of Toronto's zoning and licensing requirements layer additional rules on top of the Building Code minimums. The suite must have at least one means of egress directly to the exterior without passing through another dwelling unit. Confirm your specific requirements with the City or your contractor before finalizing the design.
Egress window installation in Toronto typically costs between $3,500 and $9,500 per window, including excavation, the window well, the window unit itself, waterproofing, and restoration. The range is wide because the variables are significant: the depth of your foundation, the soil conditions, whether the wall is poured concrete or block, and how complex the drainage situation is.
The table below breaks down the cost components for a typical egress window installation in a Toronto home with a poured concrete foundation at approximately 7 to 8 feet depth.
| Cost Component | Typical Range (CAD) | Notes |
|---|---|---|
| Permit (City of Toronto) | $200 – $400 | Based on construction value; required for structural opening |
| Excavation & window well | $800 – $2,000 | Varies significantly by depth and soil conditions |
| Concrete cutting & lintel | $700 – $1,500 | Poured concrete walls require diamond-blade cutting and a structural lintel |
| Window unit (casement or slider) | $400 – $1,200 | Vinyl vs. fibreglass; ENERGY STAR certification adds cost |
| Window well cover | $150 – $400 | Polycarbonate dome or custom steel grate |
| Waterproofing & drainage | $400 – $1,200 | Drainage gravel, membrane, and connection to weeping tile where applicable |
| Interior framing & finishing | $300 – $800 | Drywall, trim, interior sill; scope varies by existing finish level |
| Total (single window) | $3,500 – $9,500 | Most Toronto projects fall between $4,500 and $6,500 |
Several factors can push an egress window installation toward the top of the range or above it:
If you are finishing a basement with two or three bedrooms, installing multiple egress windows at the same time produces meaningful savings. The permit, mobilization, and concrete cutting equipment are largely fixed costs. On a two-window project, the per-window cost typically drops by $400 to $800 compared to doing them separately. On a full basement renovation where we are already on site for several weeks, the egress windows integrate into the broader project workflow rather than requiring a separate mobilization.
An egress window installation requires a building permit from the City of Toronto Building Division. This is a structural opening in a foundation wall — you cannot cut into a bearing wall without engineering sign-off, and the City needs to inspect the work.
The permit application requires drawings that show the proposed opening size, the lintel specification, and the window well dimensions. For a straightforward single-window installation in a standard Toronto semi or detached, permit approval typically takes two to four weeks through the City's online portal. Complex projects or those in heritage zones may take longer.
Your contractor should pull the permit in their own name as the registered contractor — not ask you to pull it as the homeowner. When you pull a permit as a homeowner, you become the general contractor of record and assume liability for the work. Reputable contractors handle this routinely; any hesitation about pulling permits in their own name is a meaningful warning sign.
Do not skip the permit: Unpermitted foundation work is one of the most problematic disclosures in a Toronto real estate transaction. It will surface on a home inspection, it may void your property insurance for related claims, and the City can require you to expose and redo the work at your expense to verify compliance. The permit fee is a small fraction of the total project cost — it is not worth avoiding.
A well-run egress window installation follows a predictable sequence. Understanding it helps you plan the disruption and set realistic expectations about how long your backyard and basement will be affected.
Before a shovel goes in the ground, the contractor needs to locate all underground utilities in the excavation area. In Toronto, this means calling Ontario One Call (the provincial utility-locate service) to mark gas, hydro, water, and communications lines. This is a legal requirement before any excavation, and it typically takes three to five business days for marks to be placed. Your contractor handles this, but it is one reason a project cannot start the day after you sign a contract.
During this period, the window unit is also ordered. Delivery lead times for custom-sized windows — particularly casements sized specifically for egress compliance — can run two to four weeks from some suppliers. Experienced contractors order the window before excavation begins so the opening is not sitting open and exposed while waiting for the unit to arrive.
Exterior excavation is typically done mechanically with a mini-excavator where site access allows, or by hand in tight-access situations. The excavation area needs to extend approximately 600 mm beyond the planned well opening on each side to give workers room to operate. The window well — usually a corrugated galvanized steel half-cylinder, though precast concrete options are available — is set against the foundation wall and backfilled on the exterior sides. Drainage gravel is placed at the base of the well and connected to the weeping tile system where one exists.
This is the most technically demanding part of the job. A diamond-blade concrete saw cuts the rough opening in the foundation wall. The cuts must be precise — too wide and the structural integrity of the wall is compromised, too narrow and the window will not fit. Once the opening is cut, the concrete section is removed and a steel lintel (typically a W-shape or HSS section specified by the engineer of record) is installed to transfer the load around the opening. The lintel bears on the existing wall on both sides of the opening and must be set and grouted correctly before any load is restored.
In block-wall foundations, the process is similar but the mortar joints between blocks create natural cut lines that can be used strategically. The lintel installation in block walls requires more care because the bearing courses need to be properly supported during installation.
The window unit is set in the rough opening, shimmed level and plumb, and fastened to the surrounding masonry. The critical work here is the waterproofing: a flexible membrane is applied around the perimeter of the opening on the exterior, lapping over the window well flange and integrating with any existing damp-proofing on the foundation wall. Where the foundation has existing waterproofing or a drainage membrane, the new work must tie into it correctly. Sealant is applied at all penetration points, and a backer rod is used at joints too wide for sealant alone to bridge reliably.
On the interior, the rough opening is framed with pressure-treated lumber at the sill (which may be in contact with the concrete) and regular framing lumber elsewhere. Insulation is installed in the new frame cavity to prevent cold bridging at the opening perimeter — this is often skipped on quick jobs and shows up as frost or condensation on the interior window frame in winter. Drywall, trim, and an interior window sill complete the visible finish. The scope of interior finishing varies significantly depending on whether the basement is already finished or is being finished as part of the same project.
A framing and structural inspection is required before the exterior is backfilled and the interior walls are closed up. The inspector verifies the lintel installation, the window dimensions, and the rough opening construction. Once the inspection is passed, exterior backfill is completed, grading is restored, and any landscaping disturbed by the excavation is addressed. Final exterior grading should slope away from the foundation — ideally at least a 2% grade over the first 1.8 metres — to keep surface water away from the new window well.
Not all window styles work equally well as egress windows. The choice affects both compliance and long-term usability.
A casement window — hinged on one side and swinging outward — is the most common egress window choice for Toronto basements. When fully open, the entire sash area is available as clear opening, which makes it easy to meet the 0.35 m² minimum with a relatively compact unit. Casements are also more airtight and energy-efficient than sliders when closed, which matters for below-grade spaces where thermal performance is already a challenge. The main limitation is that the outward swing requires clear space in the window well, so the well needs to be sized accordingly.
A horizontal sliding window is the second common option. The clear opening area is only half the total sash area (because one panel is fixed), so the window unit itself needs to be larger to achieve the same egress compliance. Sliders are simpler mechanically and less expensive than casements, but they do require a wider window well to achieve the same egress dimensions. In basements where vertical space in the well is constrained, a slider can be a better fit because it does not require outward swing clearance.
A window well cover is worth installing on virtually every egress window in Toronto. The reasons are practical: an uncovered well collects leaves, debris, and water during our wet springs and falls, and it becomes a minor maintenance burden year-round. More importantly, an uncovered well is a fall hazard for small children and pets. Polycarbonate dome covers that are rated for adult weight and secured but easy to push open from below (a Building Code requirement for egress wells) cost $150 to $400 and are a straightforward add-on during installation.
The cover must be openable from inside the well without tools — it cannot be locked or latched in a way that prevents escape. This is a life-safety requirement, not a preference. Any cover that is bolted down or padlocked defeats the purpose of the egress window entirely.
For a single egress window installation on a Toronto detached or semi-detached home, the overall project timeline from initial consultation to completion typically runs four to six weeks. The breakdown is roughly as follows:
These timelines assume standard soil conditions, no access complications, and a window unit that arrives on schedule. Projects where the egress window is part of a larger basement renovation often have more flexibility on sequencing, since the egress window can be installed early in the rough-in phase and interior finishing happens as part of the broader project schedule.
In most cases, homeowners do not install egress windows in isolation. They are driven to it by a basement renovation: finishing an unfinished lower level, converting space to a bedroom or home office, or creating a legal secondary suite. When that is the context, the egress window is one component of a larger project rather than a standalone scope.
Integrating egress window installation into a full basement renovation has real advantages. The permit can be consolidated, the site is already open, and the concrete cutting and framing are coordinated with the broader rough-in rather than being a separate mobilization. Interior finishing — the drywall, trim, and sill — flows naturally into the rest of the basement finishing work without seams or transitions that are obvious when the window is added after the fact.
If you are planning a basement renovation in Toronto, we almost always recommend addressing egress compliance as part of the initial design rather than discovering late in the project that a window needs to be enlarged or added. The cost of doing it as part of the renovation is lower than doing it as a retrofit, and the result is better integrated.
Egress window installation involves concrete cutting, structural work, waterproofing, and below-grade drainage — it is not a simple window replacement. The contractor you hire needs to be competent in all of these areas, not just one of them. There are a few things worth verifying before you commit:
An egress window installation in Toronto costs between $3,500 and $9,500 for a single window, takes four to six weeks from consultation to completion, and requires a building permit and structural engineering sign-off. It is not the most glamorous line item in a basement renovation budget, but it is one of the most consequential — for the safety of the people who sleep in that space, for the legal habitability of the room, and for the long-term value of your home.
Done correctly, with proper waterproofing, a well-drained window well, and a quality window unit, an egress window should perform without issue for the life of the building. Done poorly — without a permit, without adequate waterproofing, or with a window that does not actually meet the minimum dimensions — it becomes a liability that you will eventually have to redo at additional cost.
At Kopman Build, we have been doing this work in Toronto since 1999. We handle the full scope: permit application, utility locates, excavation, concrete cutting, structural engineering coordination, window installation, waterproofing, and interior finishing. If you are planning a basement renovation or need to bring an existing basement bedroom into egress compliance, we offer no-obligation consultations and will give you a straight assessment of what is involved and what it will cost. Get in touch here.
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