Canadian building code question

What are the building code requirements for egress windows in Canada?

Bedrooms require at least one egress window or exterior door that provides a minimum unobstructed opening for emergency escape. The code specifies minimum opening dimensions, maximum sill height above the floor, and window well requirements for below-grade installations.

Egress window compliance is one of the most frequently failed inspection items in residential construction, especially for basement bedrooms. The requirements cover not just the window size, but the clear opening, sill height, operability, and window well dimensions for below-grade conditions. Confirm these requirements early in design to avoid costly rework.

What to check first

  • Every bedroom requires at least one egress window or exterior door that meets the minimum unobstructed opening size.
  • The maximum sill height above the floor is limited to allow occupants to reach and use the window in an emergency.
  • Below-grade egress windows require window wells that meet minimum dimension and drainage requirements.

Jurisdiction notes

National baseline

The NBC Part 9 sets the minimum unobstructed opening size, maximum sill height, and window well requirements for bedroom egress windows.

Province and edition check

Provincial codes may amend the minimum opening dimensions or add requirements for specific window types. Confirm the adopted code edition.

Below-grade considerations

Window wells for below-grade bedrooms have specific minimum width, projection, and drainage requirements that are separate from the window opening size.

Work through it in this order

  1. Identify every bedroom that requires an egress window, including basement bedrooms.
  2. Verify the minimum unobstructed opening size for each egress window under the applicable code.
  3. Confirm the maximum sill height above the finished floor.
  4. For below-grade bedrooms, check the window well dimension, clearance, and drainage requirements.
  5. Verify that the selected window hardware allows the window to be opened without special tools or knowledge.
  6. Confirm the requirements with the local building department before ordering windows.

Common questions

What is the minimum egress window opening size?

The NBC sets a minimum unobstructed opening for bedroom egress windows. The specific dimensions depend on the code edition and provincial adoption. Verify the requirement for your project.

Do all basement bedrooms need egress windows?

Yes. Every bedroom, regardless of floor level, requires at least one egress window or exterior door that meets the minimum opening requirements.

Can a casement window meet the egress requirement?

Yes, if the unobstructed opening when the window is fully open meets the minimum size and the sill height is within the allowed maximum.