What is an egress window?
An egress window is a window that can be used as an exit in an emergency. In order for a room to be considered a finished and habitable room building codes require an exit point large enough for a person to escape—this is either a door or an egress window. Egress windows are required in bedrooms and in finished basements.
Egress window measurement requirements
According to International Building Code, every bedroom must contain at least one egress window. This window must be:
- At least 20 inches wide by 24 inches high
Additionally, the egress window must have:
- A total area of at least 5.7 square feet
- The opening must be no higher than 44 inches from the floor
These requirements are crucial for facilitating quick and easy escape in a fire or other emergency. Individual states and local municipalities may also have their own specific codes regarding egress windows.
There are additional standards for egress windows installed in basements. Basement egress windows must be:
- At least 36 inches in both height and width with a fully functional opening
- If the window is more than 44 inches from the ground, there must be a ladder or steps at least 12 inches wide
If your egress window is beneath a deck, standards require at least 36 inches of space between the bottom of the deck and the top of the window. If there’s more than one bedroom or habitable living space in your basement, each space will need at least one egress window.
What kind of egress window should I choose?
Egress windows come in a variety of styles—double hung, casement, and gliding. Awning windows are sometimes used as well, but these won’t work in basements and can present safety risks when used for emergency exits from higher floors.
Casement: Windows that are side-hinged and open outward either to the right or left. This is the most popular type of egress windows, often used in basements.
Double-hung: Windows with two panes of glass. Even when fully open, more than half of a double-hung window’s overall area is blocked by glass, making it difficult to meet the minimum 5.7 square foot requirement for basement windows.
Gliding: Windows that slide horizontally. To meet egress requirements, gliding windows must be at least 4 feet wide and 4 feet high. Gliding egress windows are great for basements if you have the space.
To meet building code standards, double-hung and gliding egress windows require more space than do casement windows.