Minimum Requirements Differ
Few of us think of a bedroom window as a "life-saving" feature. Although bedroom windows are not
considered to be ordinary escape routes, if there was ever an emergency situation, like a house fire,
having the properly-sized egress window in the bedroom could be the difference between life and
death. By the time an occupant is able to respond to a smoke alarm the suite may be filled with
smoke and their escape route from the bedroom blocked.
Did you know: "...
a bedroom in Ontario does not require an egress window in the actual bedroom!"
The requirement for a properly-sized bedroom window has been around since 1980 and subsequent code
changes since then have made it even easier to understand how a bedroom egress window is defined.
Or has it? Depends on which code you reference. Regional requirements can differ from national regulations.
National Building Code of Canada
The National Building Code of Canada (NBCC), on which the Provincial Codes are based, has very clear
requirements as it relates to bedroom windows and how the bedroom window serves three distinct purposes
in the home:
Light (at least five per cent of the floor area served)
Ventilation (at least 0.28m² or 3 ft² or an adequate year-round mechanical ventilation)
Emergency Escape: 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).
Building Code article 220.127.116.11. establishes the general requirement that all bedrooms must have at
least one window that is large enough to be used as an exit in an emergency. The specific requirements
are as follows:
Except where the suite has a sprinkler, each bedroom or combination bedroom shall have at least
one outside window or exterior door operable from the inside without the use of key, tools or
special knowledge and without the removal of sashes or hardware.
The window referred to in Sentence (1) shall provide and unobstructed opening of not less
than 0.35 m² (542 in² or 3.8 ft²) in area with no dimension less than 380 mm
(15 inches), and maintain the required opening during an emergency without the need for additional
If the window referred to in Sentence (1) is provided with security bars, the security bars
shall be operable from the inside without the use of any tools or special knowledge.
If a window well is required, it must be out from the window at least 550mm (about 22") to provide
safe passage. Awning style windows for example opening into a window well typically won't work
because they tend to obstruct clear passage unless the window well is unusually large.
It is further recommended that the bottom of any egress window opening or sill not be higher than
1.5m (5 feet) above the floor. Now this can be somewhat challenging for any bedroom in a basement,
so some means of built-in furniture below the window to assist in the event of an emergency is required.
Ontario Building Code
This may come as a surprise to many people, or a relief to those looking to add a bedroom in the
basement, but contrary to the National Building Code and popular brief, a bedroom in Ontario does
not require an egress window in the actual bedroom! As long as there is an egress window or door
to the exterior somewhere on the level, the requirements for egress have been met. However, there
are still light and ventilation requirements for each bedroom that must be met, but that is another
Egress from Bedrooms (OBC 9.9.10 - 2012)
Egress Windows or Doors for Bedrooms (18.104.22.168)
Except where a door on the same floor level as the bedroom provides direct access to the exterior,
every floor level containing a bedroom in a suite shall be provided with at least one outside window that,
is openable from the inside without the use of tools,
provides an individual, unobstructed open portion having a minimum area of 0.35 m² (3.8 ft²) with
no dimension less than 380 mm (15 inches), and
maintains the required opening described in Clause (b) without the need for additional support.
Except for basement areas, the window required in Sentence (1) shall have a maximum sill height
of 1,000 mm (39 inches) above the floor.
When sliding windows are used, the minimum dimension described in Sentence (1) shall apply
to the openable portion of the window.
Where the sleeping area within a live/work unit is on a mezzanine with no obstructions more
than 1,070 mm above the floor, the window required in Sentence (1) may be provided on the main level
of the live/work unit provided the mezzanine is not more than 25% of the area of the live/work unit
or 20 m², whichever is less, and an unobstructed direct path of travel is provided from the
mezzanine to this window.
Where a window required in Sentence (1) opens into a window well, a clearance of not less
than 550 mm (22 inches) shall be provided in front of the window.
Where the sash of a window referred to in Sentence (5) swings towards the window well, the
operation of the sash shall not reduce the clearance in a manner that would restrict escape in an emergency.
Where a protective enclosure is installed over the window well referred to in Sentence (5),
such enclosure shall be openable from the inside without the use of keys, tools or special knowledge of the opening mechanism.
In short, the required window size for egress is the same between the National Building Code and the
Ontario Building code. Window well requirements are the same as well. The significant difference between
the codes is that a means of egress is required for each bedroom with the National Building Code, while
only one means of egress per level is required with the Ontario Building Code. Also, the National Building
Code requires the sill height from the floor to be no more than 1,500mm (59 inches), while the Ontario
Building Code requires the sill height to be no more than 1,000mm (39 inches).
Fire Code Requirements for Rental Units
The Ontario Fire Code requirements are different still, particularly when it comes to rental properties, such
as boarding, lodging and rooming houses. The code states that each floor area shall be served by at least two exits.
In regards to basement bedrooms, one exit can be through the stairs to the first floor. The second exit must
be in the basement area; this can consist of a door or a properly sized window. The code does not explicitly state
that each bedroom in a basement has to have an egress window, as long as there are two means of escape. Open for
interruption by the Fire Marshall, the code states, "...alternative measures may be approved where, in the opinion of
the Chief Fire Official, they will provide protection for life safety...". Essentially, the Fire Marshall may require
each bedroom in the basement of a rental-type property to have a properly sized egress window, or he may not, as long as
there are two means of excape in an emergency. If in doubt, it is always best to check with the Fire Marshall.
International Residential Code
The International Residential Code (IRC), which is used in the United States, is different still. The IRC
states that at least one window in each bedroom must be of sufficient size to permit the occupants to escape
a fire, AND also to allow a fully outfitted fire-fighter to enter. The window size is also required to be
larger than the Canadian requirements. An egress window must satisfy all four International Residential
Code (IRC) criteria:
Minimum width of opening: 20 in.
Minimum height of opening: 24 in.
Minimum net clear opening: 5.7 sq. ft. (5.0 sq. ft. for ground floor).
Maximum sill height above floor: 44 in.
If in doubt about whether your existing bedroom windows meet the safety requirements set out in the
Code or if you're about to undertake a basement refurbishment that will involve the windows, it's always
best to contact your municipal authorities. Local requirements may vary.
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