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A basement egress window provides a quick exit for anyone living in or using a finished basement. It is also a key element in meeting code requirements when finishing a basement. A basement egress window costs $3,725 to install.
Meet the Expert
- Justin Conzemius is the Vice-President and General Manager, Windows at Andersen Corporation.
- John Kinyon is the owner of Custom Exteriors LLC, an exterior remodeling company based in Longmont, Colorado.
Average Cost of a Basement Egress Window
Installing a basement egress window costs $3,725, with low costs starting around $2,380 and ranging to a high cost of $5,070.
The cost increases by the number of sleeping areas (basement bedrooms), the type of window, whether this is a new installation or a replacement, and if an exterior window well needs to be installed.
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What Is a Basement Egress Window?
A basement egress window is an opening in the basement exterior wall that allows users to exit quickly in an emergency.
To pass inspection, the window must meet or exceed size, height, and opening type code requirements.
Basement Egress Window Code Requirement
International Residential Code (IRC) standards adopted in many communities require each sleeping room in the finished basement to have an egress window or door. The egress window has an indoor component (the window itself) and an outdoor component (a window well).
Egress Window
- Opening height: 24 inches or taller.
- Opening width: 20 inches or wider.
- Minimum net opening size of 5.7 square feet.
- Maximum sill height of 44 inches from the floor.
- Ladder or other structure if the sill is higher than 44 inches.
- Operable parts without keys or tools for easy escape.
Window Well
On the outside of the egress window, there must be an opening for escape. Usually, this is a window well. Since egress windows are at or below ground level, the window well may need to be sunk by several feet.
- Minimum width of 36 inches.
- Must open directly to a public way (such as a street) or to a yard with a minimum width of 36 inches that opens to a public way.
Calculate Window Opening Size
To calculate code-compliant window openings, multiply the opening width by the opening height, then divide by 144.
This table includes a few of the window sizes (openings) that are allowed by code.
| Width (Inches) | Height (Inches) | Openable Area (Square Feet) |
| 20 | 41.5 | 5.76 |
| 20.5 | 40.5 | 5.77 |
| 21.5 | 38.2 | 5.70 |
| 22.5 | 36.5 | 5.70 |
| 30 | 27.4 | 5.71 |
| 31 | 26.5 | 5.70 |
| 33 | 25 | 5.73 |
Types of Windows
Any window that meets code requirements can be used as an egress window. Two types of windows work better than others: casement and slider windows. Single- or double-hung windows are another option, though height is often an issue with these windows.
Casement Windows
Casement windows work best, especially when you are cutting a larger opening, says John Kinyon, of Custom Exteriors LLC.
“They are easy to operate, and because they typically open fully, you create the maximum available opening size and ventilation,” Kinyon says.
If you want to meet egress window code requirements yet keep the window as small as possible, install a casement window. Once the window sash is out of the way, the entire window opening is open and available for exit.
Slider Windows
“Slider windows are suitable for traditional basement egress windows,” says Justin Conzemius of Andersen Windows & Doors. “They typically meet size and operational requirements to ensure a person can climb through during an emergency. These windows are also favored due to their ease of operation.”
Only half of the slider window is available for escape. One half opens, while the other half remains in place.
Single- and Double-Hung Windows
Single-hung and double-hung windows are tall and narrow. While they can be used as basement egress windows, they are often not the best choice given the limited height of basement walls.
Only the lower half of a single- or double-hung window opens and is available for escape. Since building code requires a minimum vertical opening height of 24 inches, the entire window must be 48 inches tall or more.
Other Windows
Fixed or picture windows cannot be used as egress windows because they do not open. Bay, bow, and awning windows are also poor egress window choices.
| Window Type | Average Cost | Low Cost | High Cost |
| Single-Hung | $335 | $200 | $570 |
| Double-Hung | $600 | $270 | $900 |
| Casement | $575 | $355 | $800 |
| Sliding | $1,450 | $660 | $2,240 |
Cost Factors
Number of Bedrooms
The number of bedrooms in the finished basement affects the cost of installing basement egress windows. Every bedroom—or any room where people sleep—must have an egress window.
Window Well
The cost of a window well ranges from $1,050 to $2,000, for an average cost of $1,525 per window well.
The basement egress window must open onto a large, protected opening that drains well.
Cut Window Opening
For a new installation, an opening must be cut either partially or fully into the foundation wall. It costs from $700 to $725 to cut an opening for an egress window.
Changing Window Type
If you have an existing basement egress window, changing to a different type will usually increase the cost of installation. So, if possible, it’s best to remain with the same type of window.
“If your current window meets the current codes, we usually see a like-for-like replacement,” Kinyon says.
Best Time to Install a Basement Egress Window
Install a basement egress window when the ground is dry and well-drained. In many areas, this period stretches from late spring to fall.
The ground must be dry several feet down, alongside the foundation, for the construction of the window well.
Pros and Cons
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Provides safe exit
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Creates habitable space
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More light and air
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Satisfies code
Reasons for a Basement Egress Window
It’s time for a basement egress window if you are finishing your basement and adding bedrooms or any type of room used for sleeping. It’s also time when you already have an egress window that is failing.
“If the basement egress window shows signs of wear and tear or weather or water damage or if it no longer meets current egress codes and safety standards, it’s time to replace it,” Conzemius says. “Regular inspections can help identify these issues early.”
Professional vs. DIY Installation
Installing new or replacement windows is sometimes a DIY project. But installing a basement egress window is always a job for professionals. There are two main reasons for this, Kinyon says.
“If your current window doesn’t meet the current egress code, then you will have to cut into your foundation wall to install the window,” Kinyon says. “This is a risky DIY task as your measurements and cuts must be exact to ensure a proper fit and accommodate such a window.”
Kinyon adds that the other reason is more about the window’s location and the danger of water intrusion.
“This window will be at least partially below grade. It’s a pretty important spot to risk any water penetration. A professional installation ensures a proper fit and seal.”
Installation Tips
- When replacing a small egress window with a larger one, it’s easier to enlarge vertically than width-wise to meet code requirements.
- Casement windows that swing inward—while not required by code—are often preferred because they don’t impede emergency services in the window well.
- Egress windows can have bars, grilles, and grates for security, but they must have release mechanisms that allow them to be opened from the inside without keys or special devices.
FAQ
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A basement egress window is worth it primarily for safety. It provides a quick exit in case of a fire or emergency. It’s also worth finishing the basement for permanent living or renting for income. The cost of installing the egress window may be offset by rental income or the increase in property value by adding more habitable space to your home.
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Adding an egress window significantly increases a home’s value because it is one of the most important steps in turning an uninhabited basement into a habitable space. Thus, it gives you more living space and increases your home’s resale value.
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It costs from $700 to $725 to cut a window in a concrete wall. This is a required step when installing a new basement egress window.