What is an egress window?
Monday, August 20, 2018
Egress is “a way out,” and an egress window in the building code is defined as a required alternate route out of the home in an emergency, typically a fire. All sleeping rooms must have a window of adequate size opening for a person to get out and a rescue fireman with a backpack to get in. The minimum specifications in the International Residential Code (IRC) and Florida Building Code (FBC) are:
- Minimum width of window opening: 20 inches
- Minimum height of window opening: 24 inches
- Minimum square area of opening: 5.7 square feet (5.0 square feet for ground floor)
- Maximum window sill height: 44 inches
Windows that are egress-rated are marked as such in the manufacturer’s catalogs, and it’s worth noting that the minimum width times the minimum height does not equal the minimum required square footage of opening. One of the two dimensions has to be significantly larger than the minimum. A 20-inch wide window needs to be at least 42-inches high, for example, to be acceptable. An easier solution than doing math calculations, though, is to just stick to the manufacturer’s egress-rated windows.
If you have a home that was built before the egress window building code standard, when you decide to replace the bedrooms windows it is likely your local building department will require that one new window in each bedroom meet the egress window specifications. Some jurisdictions waive this requirement.
The egress opening of a single hung or sliding window is a little less than half of the total window area because only one side can be opened at a time. But there are also specially designed windows for replacements for smaller existing openings that have a secondary hinge point on one side and the entire window assembly opens outward when the securing latch is released from inside the bedroom.
When discussing emergency exit routes, it’s also important to note that your primary exit route should not have any obstructions. No dual-keyed locks (key required on both sides of a deadbolt) are allowed at primary exit doors. While it might seem safe enough to have a key hanging on a hook near the door for a double-deadbolt lock, finding that key and then getting it into the keyhole in the dark in a smoke-filled room is not something anyone should have to endure in a fire emergency.
Also, see our blog post Why are window security bars dangerous?
To learn more about doors and windows, see these other blog posts:
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