What size window well does Ontario Building Code require for an egress window?

Ontario Building Code requires egress window wells to provide adequate space for emergency escape and firefighter access, with specific minimum dimensions that ensure the window can be safely used during an emergency.

The minimum window well dimensions under the Ontario Building Code are:

• Minimum width: 760 mm (30 inches) measured perpendicular to the foundation wall


• Minimum projection: 600 mm (24 inches) extending out from the foundation wall


• Maximum depth: 1.5 metres (5 feet) from grade to the window sill without requiring a ladder or steps

For window wells deeper than 1.5 metres, permanent steps or a ladder must be provided. The steps must be at least 300 mm (12 inches) wide with maximum 200 mm (8 inch) rise between steps.

Additional critical requirements for GTA egress window wells include proper drainage to prevent water accumulation. The window well must have a drain connected to the foundation drainage system or weeping tiles, as standing water in the well can freeze during Toronto's harsh winters and create ice dams that block emergency egress. Many contractors install a layer of clear gravel at the bottom of the well for drainage, covered with landscape fabric to prevent soil infiltration.

Window well covers are highly recommended in the GTA to keep out snow, leaves, and debris, but they must be easily removable from the inside without tools or keys. Hinged covers that can be pushed open from below are ideal. Some homeowners install clear polycarbonate covers that allow natural light while protecting the well.

Structural considerations are crucial when cutting foundation walls for egress windows in existing GTA homes. The opening typically requires a concrete lintel or steel beam to carry the load above, and the work must be designed by a structural engineer. Many older Toronto homes have stone or concrete block foundations that require specialized cutting techniques.

Cost expectations for a complete egress window installation in the GTA range from $3,000-$8,000 per window, including cutting the foundation wall, installing the window, building the well with proper drainage, waterproofing, and backfilling. The wide cost range reflects variables like foundation type, soil conditions, depth of excavation, and window quality.

Seasonal timing matters significantly in Toronto - egress window installation requires exterior excavation that's much more difficult and expensive during frozen ground conditions from December through March. Plan these projects for spring through fall when soil conditions allow efficient excavation and proper compaction of backfill around the new window well.

Need help finding a basement contractor experienced with egress window installation? Toronto Basement Remodeling can match you with professionals who understand both the building code requirements and the specific challenges of working with GTA foundation types and soil conditions.