Egress windows offer spots for members of your household to escape through in the event of a fire, flood, or other disaster. Having this type of window is especially important in basements and attics, which typically only include staircases as potential exits. Read more about egress windows in this guide, including details about the installation process and descriptions of the various types.
Importance of Egress Windows
Homeowners install egress windows primarily as a means of escape, but these windows can also serve other purposes. Read more about why egress windows are valuable below.
Emergency Exits
The main function of an egress window is to provide an emergency exit in case of a disaster. Smoke detectors are helpful but only alert you to fires rather than providing a means of escape. Egress windows also give firefighters and emergency personnel another way into your home.
Compliance
The International Building Code (IBC) and the International Residential Code (IRC) collectively regulate the use of egress windows. These codes require rooms in which people sleep to have at least one emergency opening that leads to a public street, valley, or yard landscaping. If you have more than one sleeping room in your basement, you must ensure that there’s a means of escape in each.
Pro Tip
- According to This Old House Magazine, to meet code and provide adequate room to move through, an egress window must hit specific minimums: a clear opening of at least 5.7 square feet, a window opening at least 20 inches wide, an opening at least 24 inches tall, and a windowsill no more than 44 inches above the finished floor.
Extra Light and Ventilation
Egress windows allow extra light to enter your house, creating a more inviting atmosphere. Egress windows can also promote cross ventilation if they’re placed strategically and may make your sleeping rooms more comfortable.
Higher Property Value
An egress window can increase the value of your property by turning nonliving areas into official sleeping spaces. Your property value could increase by a few thousand dollars if you bring part of your house up to code by adding an egress window.
Egress Window Requirements
The main requirements of egress windows are included below.
Size
Not all standard windows can serve as egress windows. Egress windows must have the following dimensions, according to the International Code Council (ICC):
- Minimum opening area of 5.7 square feet
- Minimum opening height of 24 inches
- Minimum opening width of 20 inches
These dimensions allow household members, including those with mobility issues, to exit the building safely.
Pro Tip
- To see how these numbers translate in practice, consider a real-world example featured in This Old House Magazine (Spring 2024): a pair of 21-by-40-inch egress casement windows installed with the sill sitting 40 inches above the basement floor, well within the 44-inch maximum. Outside, the window openings sat 11 inches above grade—high enough to avoid the added complexity and expense of a window well.
Accessibility
Egress windows must be accessible to all household members and cannot be obstructed by furniture. In other words, there must be a clear opening for a window to qualify as egress. The distance between a room’s finished floor and the window can’t exceed 44 inches. Occupants must be able to leave through the window without climbing or jumping.
Operation Requirements
Egress windows must be easy to open and should not include complex operating mechanisms. The window should stay open during an emergency.
Review the status of the egress windows that are currently in your home and remember that building code requirements change over time and vary by state. Older homes are less likely to have egress windows since safety terms and laws have become stricter in recent years.
Types of Egress Windows
Certain types of windows can double up as emergency exits. Those that qualify are included below.
Casement windows are hinged on one side and swing outward like a door to reveal large openings. Homeowners crank a mechanism to operate these windows.
Casement egress windows are easy to operate and offer excellent ventilation. The downside of casement egress windows is that they require a significant amount of clearance outside, so they may not be suitable for small, tight living spaces.
Sliding egress windows have one or two sashes that slide horizontally. These windows are popular for their space-saving design and are easy to operate for people with disabilities.
The downside of using sliding windows for egress purposes is that you can only open one part of the window at a time.
Skylight egress windows open outward and offer a means of escape in the attic. They also provide plenty of natural light and are aesthetically pleasing.
The downsides of skylight egress windows are that they’re difficult to install, expensive, and sometimes tough to access.
Hung egress windows feature vertically moving sashes. They’re available as single-hung models where only one sash moves and as double-hung windows, where two sashes move. These windows are easy to operate, have classic appeal, and offer great ventilation.
The downside of hung egress windows is that they feature small openings that may not always be consistent with window code size requirements.
Awning egress windows feature hinges at the top of the window and open outward from the bottom, making them especially useful escape portals. They can also provide ventilation, even when it’s raining.
The downside of awning egress windows is that they require especially lengthy egress window wells.
Installing Egress Windows
You can install egress windows as part of a do-it-yourself (DIY) home improvement project. Make sure you have the tools listed below.
- Caulk gun
- Drill
- Hammer
- Level
- Measuring tape
- Pry bar
You may also need to rent an excavator if a window well must be dug. Keep in mind that the job could require a permit if you need to create an opening in your home as part of installation.
If you have your tools and materials ready, you can start the window installation process by following the steps below.
Prepare the Opening
Clear any obstacles and debris from the area around the opening. Use a pry bar and a putty knife to remove the existing window. Make sure you include enough space for the new window to safely open.
Install the Window Well (if Needed)
If you’re installing a basement egress window, you’ll need a window well. Dig a hole for the well outside the opening. Place the window well in the hole and secure it according to the manufacturer’s instructions.
Position and Secure the Window
Set the new egress window in the opening. Move the window’s bottom part into position and then fit the top part. Make sure the window is centered and level. You’ll likely need to use shims to ensure a snug fit. Secure the window in place by driving galvanized steel screws into the shims. Drill plot holes in advance so that you don’t accidentally crack the shims.
Pro Tip: Before setting the window into the opening, place composite shims on the sill to lift the window up approximately 1/4 inch. This creates a critical gap that allows any water that enters the system to drain out from underneath. For the same reason, do not caulk the bottom flange—you want to give water a path to escape rather than trapping it inside the assembly.
Test and Seal the Window
Test the window to make sure it opens properly and functions according to necessary local building codes. If everything is in order, you can apply caulk around the perimeter of the window to seal it. You could also add fiberglass or rock wool insulation. Install a trim around the window to conceal any remaining gaps and increase its aesthetic appeal. It’s easy to make mistakes when installing egress windows, so be careful. If you’re not confident in your abilities with DIY installation, hire a professional contractor.
Pro Tip: When fastening the window permanently, Tom Silva recommends using stainless-steel screws placed 12 to 16 inches apart around the frame. “You want to make sure they’re going into the structure of the wall, not just the sheathing,” he says. Before finishing, gun sealant between the window casing and the exterior, creating one more barrier against leaks.
Our Conclusion
If your house’s sleeping rooms don’t have suitable escape portals, you must install working egress windows. These windows could save lives in case of an emergency and also offer the benefits of fresh air and natural light. If you aren’t comfortable installing egress windows using DIY methods, hire a professional contractor to help you through the process.
FAQs About Egress Windows
What makes a window an egress window?
A window becomes an egress window when it meets the requirements of the IBC or IRC. These requirements include the window size, location, and usability of the window.
How much does it cost to install an egress window?
The cost of egress window installation in a finished basement is typically $2,500–$5,000. Aboveground and ground-level windows usually cost considerably less.
What is the difference between egress windows and regular windows?
The difference between egress windows and regular windows is a matter of functionality. Egress windows are meant to be another escape route in case of an emergency.
How do you convert an existing basement window into an egress window?
To convert an existing basement window into an egress window, make sure it suits the requirements of the IBC or IRC.
How do you install an egress window in a basement with a concrete wall?
To install an egress window in a basement with concrete wall space, hire a professional who can cut out a suitable opening for the window.
