Basement Bedroom Egress Window Requirements in Ottawa (2025 Code)

The 2025 clear-opening requirement

The core requirement is a large enough clear opening to climb through, an actual escape route, not a decorative window. Any basement room used for sleeping needs one, which is why egress is the keystone of a legal basement bedroom.

“Clear opening” is the actual gap a body passes through when the window is fully open, not the size of the frame. That distinction trips people up, because a window can look big while its openable area falls short. It’s also why simply having a window isn’t enough: the original small basement sliders in most Ottawa homes don’t provide a compliant clear opening, which is why enlarging is usually part of the job.

Window-well size and clearance

If the window sits below grade, you need a window well with enough clearance to actually climb out of it once you’re through the opening. A window that opens into a cramped well doesn’t meet the intent of the code, so the well size matters as much as the window.

Picture the whole escape, not just the window: you climb through the opening, then you have to stand and climb out of the well. If the well is shallow and tight, you’re stuck in a box, which defeats the purpose. A properly sized well gives room to get up and out, and on deeper wells a built-in ladder or step is added so a child or older adult can manage it.

Openability without tools

The window must open without tools or special knowledge, no removing screws, no keys. In an emergency, anyone in the room, including a child, has to be able to operate it instantly. That’s the whole point of the rule.

That rules out windows that need a crank stored elsewhere, security bars without a quick-release, or anything that must be unscrewed. If you add a well cover to keep out rain and leaves, sensible in Ottawa, it has to open from the inside without tools too. The test is simple: could a half-asleep child get out in seconds, in the dark?

Foundation cutting and waterproofing

Installing one means cutting the foundation wall to the new opening size. Done right, the opening is re-sealed and waterproofed so it never becomes a leak, the cutting is routine; the waterproofing is what separates a good install from a future problem.

The sequence matters: saw-cut the concrete to the new size, set the window, then seal and waterproof the perimeter so the new opening sheds water like an original one. Cutting concrete sounds dramatic, but for a crew that does it routinely it’s controlled and clean. The corner-cutting that causes leaks is skipping the waterproofing step, which is precisely the step we don’t skip.

Well drainage to prevent ice and water

The window well needs its own drainage so water and ice don’t collect against the glass over an Ottawa winter. Proper gravel and a drain connection keep the well dry and the window operable year-round.

This is the detail Ottawa’s freeze-thaw winters punish. A well without drainage fills, then freezes solid against the glass, at best the window won’t open, at worst meltwater finds its way inside. A gravel base tied into the foundation drainage keeps the well dry, the window operable, and your new escape route actually usable in February.

Permit and inspection path

Finally, enlarging a foundation opening is permitted work. The permit and inspection confirm the window meets code and make it count toward a legal bedroom or suite, so it’s documented value, not just a hole in the wall.

The permit is also what links the window to the bigger goal. An inspected, documented egress window is what lets the City, and later a buyer or appraiser, recognize the room as a legal bedroom. Without it, you’ve spent money on a nicer window; with it, you’ve added a legal, countable bedroom to the house.

Frequently asked questions