Canadian building code question

What are the building code requirements for window fall prevention in Canada?

The NBC requires fall protection for operable windows where the sill height is below the required guard height and the window opens enough for a person to fall through. Requirements include opening limiters, guards, or window configurations that prevent falls, with specific provisions for residential buildings and dwelling units.

Window fall prevention has become an increasingly enforced code requirement, particularly for residential buildings with children. The code addresses both the sill height relative to the floor and the maximum opening size of operable windows at height. The requirements vary by building type, storey, and whether the window is in a dwelling unit.

What to check first

  • Operable windows with sill heights below the required guard height may need opening limiters or guards to prevent falls.
  • The code sets maximum opening sizes for windows that can be opened without a limiter in certain locations.
  • Provincial editions may add specific window fall prevention requirements beyond the NBC baseline, especially for residential buildings.

Jurisdiction notes

National baseline

Start with the NBC guard height requirements and the provisions for operable windows at or above the elevation where guards are required.

Province and edition check

Some provinces have adopted enhanced window fall prevention requirements, particularly for multi-unit residential buildings and dwelling units with children.

Interaction with egress windows

Fall prevention requirements must be balanced with egress window requirements — limiters cannot prevent emergency escape use where egress windows are required.

Work through it in this order

  1. Identify all operable windows and their sill heights relative to the floor and to the exterior grade or surface below.
  2. Determine whether the window location requires fall protection based on height above grade and guard requirements.
  3. Select the appropriate fall prevention method: opening limiter, guard, or window configuration.
  4. Verify that fall prevention measures do not conflict with egress window requirements where applicable.

Common questions

At what height are window opening limiters required?

The trigger depends on the sill height relative to the floor and the drop height to the surface below. Verify the specific height thresholds in the applicable code edition.

Can opening limiters be used on egress windows?

Limiters on egress windows must be releasable without tools or special knowledge to allow emergency escape. The device must satisfy both fall prevention and egress requirements.

Do all provinces require window fall prevention?

Requirements vary by province and code edition. Some provinces have adopted enhanced requirements beyond the NBC baseline. Check the applicable provincial code.