In Toronto, the Ontario Building Code (OBC) 9.9.10.1 requires a basement egress window — with a clear opening of at least 0.35 m² (3.8 sq ft), a minimum width and height of 380 mm (15 in) each, a sill no higher than 1,000 mm (39 in) above the finished floor, and a permanently affixed ladder in window wells deeper than 1,200 mm (4 ft) — in any basement containing a sleeping room, bedroom, or recreation space that needs a secondary exit. This is a legal requirement, not a design suggestion: when Toronto Building inspects a basement bedroom or secondary suite, a missing or undersized egress window fails the inspection, and the space stays non-compliant.
Toronto egress window code: the numbers that matter
Section 9.9.10.1 of the Ontario Building Code governs egress windows and doors from below-grade spaces. It works alongside Section 9.7.3.4, which sets the window opening rules. Together, they define what a Toronto basement egress window must do:
- Clear opening area: at least 0.35 m² (3.8 sq ft), measured with the window fully open — not the glass area.
- Minimum width and height: each dimension must be at least 380 mm (15 in). Narrow horizontal sliders fail this even when their square footage looks close.
- Sill height: the openable bottom edge can sit no higher than 1,000 mm (39 in) above the finished floor. An adult must be able to get out without climbing equipment.
- Operable from inside, without tools: no keys, no special levers, no padlocked security bars. The window must open completely in an emergency. Many older Toronto homes have burglar bars on basement windows — those need a quick-release mechanism or they don't count.
- Window well size: the well must not reduce the window's clear opening. In practice, that means at least 900 mm x 900 mm (3 ft x 3 ft) of interior space so a person can turn around and climb out.
- Ladder or steps for deep wells: any well deeper than 1,200 mm (4 ft) requires a permanently affixed ladder or steps designed for a safe exit.
The deep-well rule matters more in Toronto than most homeowners expect. Because most basement floors sit 7 feet or more below grade, a properly sized egress well is almost always deeper than 1,200 mm — which means a fixed ladder is part of the job, not an optional add-on.
When does a Toronto home need an egress window?
You need a code-compliant egress window (or an exterior door at grade) in these situations:
- Basement bedrooms. Any below-grade room that can be used for sleeping needs two exits: the interior stair plus an egress window.
- Secondary suites. Legal basement apartments in Toronto require a compliant egress window in every sleeping room. This is one of the top reasons an illegal basement apartment gets an order to comply.
- Recreation rooms. A basement rec room, home office, or gym counts as potential sleeping space. Toronto Building applies the egress requirement there too.
- Major renovations. The moment you change the layout, add a bedroom, or finish below-grade space, current code rules apply to the new work.
Older Toronto neighbourhoods — Leslieville, The Beaches, High Park, Riverdale — have hundreds of houses built between the 1920s and 1950s with tiny original basement hopper windows. Those windows are nowhere near the 0.35 m² opening the code demands. If you're renovating one of these homes, the egress window upgrade is often the single biggest item in the basement scope of work.
Permits and inspections: what Toronto Building expects
Installing an egress window in Toronto requires a building permit. The job means cutting foundation, excavating soil, and installing a window well — none of that is a "repair," and none of it is legal without a permit from Toronto Building.
Egress Window Pros Toronto manages the permit application as part of the project. The application includes a floor plan showing the room, the proposed window dimensions, and the well details, along with the OBC references the inspector will check against.
One critical step: no backfill before inspection. The inspector needs to see the drainage connection and the window before soil goes back in. We schedule the inspection ourselves and never bury work that hasn't been signed off.
Skip the permit and you risk a field order from Toronto Building — which means re-excavating at your cost, plus possible fines and complications at resale. Home inspectors and title searches catch missing permits, and buyers' lawyers ask about them on every GTA resale.
What a code-compliant installation includes
When we install an egress window, this is what's in the scope:
- A window properly sized to OBC 9.9.10.1 and 9.7.3.4 — no "close enough" openings
- A steel or polymer window well large enough for escape, with a gravel base for drainage
- Drainage tied into the foundation drainage system, with waterproofing on the exposed foundation wall
- A permanently affixed ladder or steps where the well exceeds 1,200 mm