What is an Egress Window? How it Should Be Done Right

Updated: August 2020

Exit windows provide an escape route in case of fire, flood and other disasters. They provide a safe exit from a burning building, conserve your belongings and prevent smoke damage by allowing fumes to flow into the night instead of ‘bottling’ into your home.

The good news is that any window can be an exit, as long as it meets the dimensions and placement requirements. On the other hand, many homes do not have the required windows and homeowners are unaware that they are breaking the law. Basements converted into bedrooms rarely have approved exit windows. It’s also a good idea to check window specifications in guest rooms and offices. Anytime you’re remodeling a room or turning an area into a bedroom, make sure there’s room for an outgoing room that complies with the code before you begin your project. Redoing your basement bedroom to make it fireproof is easier than you think!

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Few people realize that exit windows are required by law. While not all homes will have them, especially older homes that are older than the exit laws, there are very specific regulations for their construction.

According to the International Residential Code (IRC), principles must have the following:

  • Minimum width of 20 inches and minimum height of 24 inches
  • A maximum sill height of 44 inches
    The sill height is the space between the ground and the window; it cannot be insurmountable to save teams. It must be accessible.
  • A minimum net clearance of 5 square feet for ground floor floors and 5.7 square feet for upper floors.
  • The opening is the space provided by the window once it is opened. It must be large enough for fully uniformed firefighters to climb through with air tanks on their back.

California residential exit laws have additional specifications:

Because so many fire deaths occur when residents of residential buildings are asleep at the time of a fire, the California Building Code (CBC) Section 1029 of 2010 requires that:

  • Basements in residential units and
  • Every bedroom under the fourth floor

Must have at least one operable window or exterior doorway approved for emergency escape and rescue. Such openings open directly to a public road or to a courtyard or courtyard that is open to a public road.

  • The net free open area should be no less than 5.7 square feet (5 square feet for high quality floor openings and basement window wells).
  • In addition to the above requirement, the net openable height dimension must be a minimum of 24 inches. The net free-open width dimension must be a minimum of 20 inches (Note: Using both minimum numbers will not produce the required 5.7 square feet.)

Egress Windows California Laws

Source: California building


There are a few other guidelines from the IRC you should follow.

  • Every room should have at least one window to use as a starting point, including basements and ‘bedrooms’.
  • The windows must open directly to a street, garden, courtyard or other area with “fresh air”. Windows that open into another building do not count; fires can spread between them.
  • Windows should be able to work without tools. For example, if you have bars or grilles above your window, you should be able to tear them off in an emergency without the use of wrenches or drills.

Whether you’re building a new home or just remodeling your second floor, consider this your guide to getting out of windows. They may take some time and planning to install, but your family’s safety is worth it. You never know when a disaster will strike, so it’s better to be prepared.

Please note this post is for informational purposes only. Contact the International Residential Code (IRQ) for more information on outgoing window requirements.

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