We don't often think of the windows in our homes as potentially life saving equipment. In case of a fire or other disaster, the opening portion of a window must allow for a firefighter wearing his/her gear to be able to enter. Please keep in mind that not all building codes are retroactive ( otherwise, home owners would be forced to constantly upgrade their homes ). Please note that not all building codes are retroactive. Please visit the
Canadian Building Codes for restrictions & exceptions of egress windows and other building codes.
To allow for a potential escape, the unobstructed opening for a window, to meet current ( circa 2013 )egress codes, must be 542 square inchs ( 0.35 square meters ) with no horizontal nor vertical side measurement being less than 15".
That is why the National Building Code of Canada (NBCC) has very clear requirements as it relates to bedroom windows and how a bedroom window can serve three distinct purposes in the home:
1) Light (
at least five per cent of the floor area served) 2) Ventilation
(at least 0.28m2 or 3 ft2 or an adequate year-round mechanical ventilation) 3) Emergency Escape: (
Article 9.7.1.3 & 9.7.1.4) An Emergency Escape requires that each bedroom must have a door that leads directly to the exterior of the building or have a properly-sized egress window that can be opened from the inside without the use of keys, tools, hardware or
special knowledge* (
unless this bedroom has a sprinkler system installed).
The size of an egress window is not based on the physical size of the window frame, but on what the unobstructed clear opening is (
once the window has been fully opened).
For a bedroom window to be compliant it must provide an unobstructed opening with a minimum area of 0.35m² (3.77ft²) and at the same time no horizontal or vertical dimension / opening can be less than 380mm (15”).
It is further recommended that the bottom of any egress window opening or sill not be higher than 1.5m (5ft) above the floor. Now this can be somewhat challenging for any bedroom in a basement, so they recommend installing some means of built-in furniture below the window to assist in the event of an emergency.
However, if a bedroom window opens into a window well, then the window well must allow at least 550mm (21.7”) in front of the window. This is to ensure that the window well does not obstruct or block the ability to use the window as a means of emergency escape. Where a casement-type window is used, the window well must also project out enough to allow for the full 90
o swing of the window opening.
Unfortunately, an out-swing awning window is usually not permitted for egress when it opens into a window well, as it tends to fully block all means of escape.
Where a window opens into a window-well, a clearance of not less than 23" ( 550mm ) shall be provided in front of the window. For additional restrictions for bedroom egress window that open into a window-well requirements please visit http://edmonton.capitall.ca/images/brochures/Building%20Codes/Building%20Codes%20in%20Canada.pdf
Reference:
http://thechronicleherald.ca/homesnews/97691-proper-egress-windowshttp://edmonton.capitall.ca/images/brochures/Building%20Codes/Building%20Codes%20in%20Canada.pdf