Egress Windows for Basement Suites in Edmonton: What Homeowners Need to Know Before Renting It Out

Turning an Edmonton basement into a legal secondary suite is one of the most reliable ways to add rental income to a property. If a basement bedroom doesn't have a code-compliant egress window, though, the suite isn't legal, full stop — no permit, no rental income, and if you're already renting it out, potential liability if something goes wrong.

The good news is that egress window requirements are well-defined and, in most cases, very achievable — even in an older home with small, high basement windows that were never meant to be an exit. Here's what actually needs to be true, where the window itself fits into getting your suite approved, and what the whole process tends to look like from first measurement to final inspection.

Why Egress Windows Are Non-Negotiable

An egress window is a window large enough, and easy enough to open, that a person could climb out through it in an emergency — most importantly, a fire. Under the National Building Code – 2023 Alberta Edition, which the City of Edmonton applies to secondary suites, every bedroom in a basement suite that isn't sprinklered needs its own means of escape to the outside, separate from the main stairwell.

This isn't a formality. If the only exit from a basement bedroom is through the house's main stairs, a fire near that stairwell traps everyone below it. An egress window gives occupants — and firefighters — a second way in or out. It's also the detail insurers and lawyers point to first when a rental unit's legality gets questioned after an incident, because it's the clearest, most objective test of whether a basement was actually built to house people safely.

For a legal secondary suite, this requirement is checked directly by the City during the permit and inspection process. Skip it, and the suite doesn't get signed off, regardless of how nice the rest of the renovation looks.

The Actual Size and Placement Requirements

Edmonton's egress rules come down to a few concrete numbers, and they matter down to the millimetre during inspection:

• Minimum clear opening: 0.35 square metres. This is the unobstructed opening when the window is fully open — not the overall window size including the frame.
• Minimum dimension: 380 mm. At least one side of that clear opening (width or height) must measure 380 mm or more.
• Openable without tools. The window must open from the inside without keys, tools, or removing any sashes or hardware — a stuck or painted-shut basement window doesn't qualify even if it's technically the right size.
• Reasonable sill height. Inspectors generally look for a sill low enough that an occupant can reasonably reach and climb through it, with built-in furniture or landings sometimes used to bridge the gap.
• Window well clearance. If the window sits below grade, the window well needs enough clear space in front of it — commonly around 760 mm — for a person to actually get out, plus consideration for snow accumulation blocking the opening in winter.

Many older Edmonton homes have small hopper or slider basement windows that were installed purely for light and ventilation, long before secondary suites were common. These almost never meet the 0.35 m² / 380 mm minimums on their own, which is why egress window upgrades are one of the most frequent line items in a basement suite renovation.

What Actually Needs to Change

Getting a basement bedroom up to code generally comes down to one of two situations:

The existing opening is close, but the window itself doesn't meet code. In some cases, a larger, properly hinged or sliding egress-rated window can be installed into the existing rough opening if it was already reasonably sized, solving the problem without touching the foundation. This is the cheaper and faster path when it's available.

The existing opening is too small. This is the more common scenario in older homes, and it means enlarging the foundation opening to fit a code-compliant window and window well. This is structural work that typically involves a general contractor or foundation specialist working alongside your window supplier — cutting concrete, resizing the opening, and installing a new window well are outside the scope of a glass and window company on their own, but the two pieces of work go hand in hand.

Either way, the window itself needs to be correctly sized, properly rated for below-grade installation, and sealed against Edmonton's freeze-thaw cycles — a poorly sealed egress window is a common source of basement leaks and frost buildup, which defeats the purpose of the renovation. Our doors and windows installation service covers supplying and fitting code-compliant egress windows into new or existing basement openings, sized and sealed for the finished opening your contractor provides.

Choosing the Right Window Style and Material

Not every window that meets the size requirement is a good fit for every basement. The style you choose affects how much usable floor space it eats up, how the room feels, and how much maintenance it needs over the years.

Casement and awning-style egress windows hinge outward and open wide, which tends to be the easiest way to meet the clear-opening requirement without needing an oversized window — the full sash swings out of the way rather than sliding, so the whole frame counts toward the clear opening.

Sliding basement windows can work, but because only half the window opens at a time, the frame often needs to be noticeably larger overall to hit the same clear-opening number — worth knowing before you commit to a rough opening size.

Frame material matters more in a below-grade application than most homeowners expect. Vinyl resists moisture and doesn't conduct cold the way aluminum does. Fibreglass costs more but holds its shape through repeated freeze-thaw cycles. Aluminum-framed egress windows exist but generally need thermal breaks to avoid becoming a condensation and frost point in an Edmonton winter.

Glazing is worth getting right the first time, too. Double-glazed, low-E units are close to standard for any below-grade window in this climate, and some homeowners opt for triple glazing on egress windows specifically because they sit closer to grade and the cold ground than a typical main-floor window.

Window Wells: The Part People Underestimate

A window well isn't just a shell holding back dirt — it's part of the egress path itself, and the City inspects it accordingly.

Beyond the roughly 760 mm of clear floor space in front of the window, a well deeper than about a metre typically needs a permanently affixed ladder or steps built into the wall, since an occupant escaping a fire shouldn't need to find and set up a ladder first. The well also needs drainage at the base — usually a gravel sump connected to weeping tile or a drain — so it doesn't fill with rain or snowmelt and effectively seal the window shut with water or ice.

What This Usually Costs and How Long It Takes

Costs vary block by block depending on foundation thickness, soil conditions, and how much of the work is structural versus just the window itself, but scope generally falls into two camps:

• Window swap only, where the existing opening is already close to code and just needs a properly sized, egress-rated window installed, is the least expensive and fastest option — often completed in a day once the window is on hand.
• Enlarging the opening, which involves cutting the foundation, installing a new window, and building a compliant window well, is a longer project. It typically requires coordinating a contractor for the concrete cutting and structural work alongside the window supplier, and can take anywhere from a few days to a couple of weeks depending on scheduling and weather.

Winter installation is possible in Edmonton but adds complexity — concrete cutting and excavation are harder in frozen ground, and window wells poured or backfilled in freezing temperatures need extra care to cure and settle properly. Many homeowners try to schedule the structural egress work for spring through fall, even if the rest of the suite renovation happens over winter.

Common Mistakes That Delay Approval

A few issues come up repeatedly when basement suites fail their first inspection on the window front, and most are avoidable with a bit of planning before work starts:

Measuring the frame instead of the clear opening. A window that's technically a certain size on the box can still fail if the operable sash, once open, doesn't leave the full required clearance.

Assuming any window well is good enough. A shallow decorative well built for a light-and-ventilation window rarely meets the depth, clearance, and drainage standard a true egress point needs.

Forgetting the permit sequence. Inspectors generally want to review egress window plans before the concrete gets cut, not after. Starting foundation work without the permit in hand can mean redoing work if the City requires a different size or placement.

Overlooking interior obstructions. A code-sized window can still be blocked by a furnace duct, plumbing stack, or built-in closet on the inside wall. The escape path needs to be clear all the way from the bedroom floor to outside.

Skipping proper below-grade sealing. Persistent moisture at a below-grade opening can lead to mould or frame deterioration that eventually compromises the window's ability to open freely — which circles right back to the code requirement.

Egress Windows vs. Egress Doors: Which One Do You Need?

Not every basement bedroom has to solve this with a window. The code also allows a door directly to the outside — a walk-up basement entrance, for example — to serve as the required means of escape instead. For homes with a walkout basement or a side-yard stairwell already leading to a door, this can sometimes be the more practical fix, especially where thick foundation walls or drainage issues make a window well difficult.

That said, a door-based solution still has to meet its own size and swing clearance rules, and it doesn't help with natural light the way a window does. For most basement suites without an existing walkout, adding or enlarging a window remains the more common — and often more cost-effective — path, since it solves both the code requirement and the liveability of the room at once.

Working With a Window Professional: What to Ask For

Because the clear-opening measurement is what actually gets checked at inspection — not the nominal window size on the label — it's worth being specific when getting quotes. A few questions worth asking before work begins:

• Can you confirm, in writing, the clear opening this specific window will provide once installed — not just the rough opening or frame dimensions?
• Is this window rated for below-grade installation, and what glazing package do you recommend for a basement application in this climate?
• If the foundation opening needs to be enlarged, who is coordinating the concrete cutting, the window well, and the drainage — is that included, or do I need a separate contractor?
• What's the expected timeline from order to installation, and does that change with the season?

Getting clear answers up front avoids the common scenario where a window arrives, gets installed, and only then turns out to fall just short of the minimums once the actual operable clearance is measured — a mistake that means removing and replacing a window already in the wall.

Don't Forget the Permit

Even if the window itself is perfect, a secondary suite without a permit isn't legal — and permits are where egress compliance actually gets verified. Before starting any window work, it's worth confirming your property's zoning and permit requirements directly through the City of Edmonton's Secondary Suites page, which outlines zoning eligibility, permit types, and the inspection process in detail.

Requirements can be updated, so confirming with the City before finalizing window sizing is a better approach than relying on what a previous project or a neighbour's suite needed a few years ago.

Maintaining an Egress Window Once It's Installed

Passing inspection is the beginning of the window's job, not the end of it. Because tenant safety depends on the window staying operable for as long as the suite is occupied, a bit of ongoing upkeep matters:

• Check that the window still opens fully and easily at least once or twice a year, particularly after winter, when frame swelling or ice buildup around the sash is most likely.
• Keep the window well clear of leaves, snow, and debris so the clear-opening space in front of the window stays usable.
• Inspect weatherstripping and seals periodically — below-grade windows are more exposed to ground moisture than above-grade ones.
• If the well has a cover, make sure it still opens easily from inside and hasn't been painted shut, iced over, or blocked by anything stored nearby.

The Payoff

A basement suite that passes inspection is the difference between a rental unit you can advertise and lease with confidence, and one that carries risk every time a tenant moves in. Egress windows aren't purely a compliance checkbox, either — a properly sized window brings in far more natural light than the small hopper windows typical of older basements, which measurably changes how livable, and rentable, the space feels.

Frequently Asked Questions