A change in the recently adopted 2020 National Building Code puts a emphasis on preventing small children from falling out of residential windows. The code change affects openable windows of residential occupancy.
For that reason, a building permit is required to change residential windows if the windows are
- Openable
- Have a sill that is more than 1.8m (6’) from the ground, and
- Have a sill that is less than than 90 cm (36”) from the interior floor.
IF all of the above are true, then the window must have what is called a Window Opening Control Device designed to limit the window opening to 10cm (4”) space.
This can mean a slider with piece of plastic inlay that limits a the opening to no more than 4”, or a similar device. (or, alternately, a guard.)
Because of these requirements, building permits are required for replacing affected residential windows.
Permit required for window replacement:
| Residential | Non-residential | |
| Expanding width on load-bearing wall. | Yes | Yes |
| Replacing bedroom window.* | Yes | n/a |
| Replacing non-openable window. | No | No |
| Replacing window less than 1.8m (6’) from ground | No | No |
| Replacing window with a sill height more than 90 cm (36”) from the floor | No | No |
| Window is openable; > 1.8m above ground, sill height <90 cm from inside floor | Yes | Yes |
(*) Not required if none of the other requirements are met AND the bedroom is served by an existing egress window or door to a patio/the outdoors.