If you’ve recently finished the basement in your home, congratulations! Having a finished basement can greatly add to the available space and value of your home.
However, you probably learned a little about building codes and heard about egress windows along the way, and now you have plenty of questions about these unique windows:
- What are egress windows?
- Why do or don’t you need them
- What are the current egress window requirements?
We have the answers to all your most pressing questions! Read on to learn everything you need to know about getting new egress windows!
What Is the Purpose of Egress Windows?
If a basement or attic is built unfinished, then it has different building codes to meet. As people won’t be living in the basement, the safety requirements are different. While there might be basement windows for ventilation, the basement windows don’t need to act as the means of an emergency exit.
But finished basements that function as bedrooms or family rooms will need to have an exit if there is a fire. The smaller window size common in an unfinished basement may not meet the safety codes necessary for your home. International residential code dictates that because of the danger of a house fire, having a means of escape is essential to safety at home.
However, egress windows meet these requirements. Egress windows have a minimum dimension that provides a secondary exit large enough to satisfy the international building code.
What are the Requirements of an Egress Window?
General Window Requirements
Depending on your local codes, requirements may differ. But to get a general sense, these are the egress requirements according to the International Residential Code:
- The unobstructed opening width of at least 20 inches.
- An opening height of at least 24 inches.
- A minimum net clear opening of at least 821 square inches—or 5.7 sq ft.
- Maximum sill height above the floor of 44 in
Net clear opening refers to the space that exists when the window is open. This refers to the actual free and clear space for a person to move through, also known as the actual opening available to people.
The minimum clear opening must be met to your local building codes – and the larger, the better!
For Windows Below Ground Level
You may not have the wall space for basement egress windows if your basement is completely underground. But you still need the requisite egress window! Luckily, there is a fix that keeps your basement underground while still meeting code and keeping the basement a habitable space.
For your basement egress window installed, you will need a window well. Window wells allow for a crawl space from the basement egress windows to the ground outside. A window well must be at least:
- 36 inches wide
- 36 inches long
- 44 inches deep or less
- If deeper than 44 inches have steps or a permanently affixed ladder (that doesn’t obstruct the open window)
- If under a structure, at least 36 inches between the top of the window well and the bottom of the porch joists or deck
These required window well dimensions ensure that the crucial lifesaving equipment of a basement egress window is accessible to anyone who needs it. Even the remote possibility of a house fire spells danger to anyone in the house.
A high window or deep window well won’t do for everyone. However, the additional support of a window well is key to keeping your home as safe as possible.
Local requirements may also vary. For example, Ontario’s egress window requirements differ from other cities. So before you begin measuring the required opening, compare your local jurisdiction to the national building code for overall square footage requirements.
Also, consider that your window can open completely, whether it’s in the attic or the basement. No sashes, hinges, or ladders should obstruct the window.
You may have screens on your egress window. But anyone should be able to easily remove the screen without tools if they need to escape the house.
How to Choose an Egress Window Style
When installing an egress window, several window types can meet the requirements. Here are the two styles we typically recommend.
Casement windows are best when you have less space to work with. That’s because casement windows function like a door that swings open due to the hinged sashes. Only requiring about 8 sq ft, you can have the casement windows you need with less structural work required.
With 16 sq ft of opening required, sliding windows need more space on your wall. However, with a beefier horizontal structural header, you can more easily increase the net opening without much structural work. So you can get that sq ft required easier than if you work vertically.
Frequently Asked Questions about Egress Windows
Egress windows are required throughout your home. But that doesn’t mean they are simple to understand all the time. These are some of the most frequently asked questions about egress windows!
What Qualifies as an Egress Window?
An egress size window allows for a person to be able to crawl through. To ensure you have the proper window, the net opening needs to meet egress requirements according to your local building codes.
Requirements include how accessible the window is from the ground and how much space is available for a person to use while they escape.
Why Would My Home Lack Egress Windows?
Whether your home was renovated or built before egress window requirements existed, you’ll want to make sure your home meets the requirements for egress windows. Most windows are egress window sizes, such as your bedroom windows.
Renovated attics or basements may lack proper egress windows because they were legally converted into an office. But attic or basement windows that serve as a bedroom have different requirements.
What Does It Mean When a Window Does Not Mean Egress?
Non-egress windows are any windows that don’t meet egress requirements. Of course, not every window needs to meet egress requirements. But at least one window in every bedroom should, according to both local and international building codes.
Your window may not meet egress requirements because it is too small for a person to escape, too high off the ground, or too difficult to open. Check your local jurisdiction to learn what the window opening needs to be for your home.
How Do I Know If My Window Is Egress?
There must be at least one egress window in any bedroom. The net clear opening needs to be large enough for a human. We recommend you measure the clearing and its accessibility. Compare it to the measurement requirements for egress windows, and get replacement windows if needed.
How Much Does an Egress Window Cost?
The price of the materials and installation depends on the location and structural work required. For example, simply replacing a window vs. building a window well will drastically change the price.
So while it may vary, the average price of egress windows ranges from $2,000 – $6,000.
Can I Have Grates on My Basement Windows?
With a basement living space, you may be concerned about security in addition to fire safety. International codes require egress windows to protect you from fires, but there are dangers outside as well.
While you can install grates, the means of escape needs to remain accessible. So the grates should not require a key or special tool to release the grates.
Can I Have Double Hung Windows or Awning Windows?
While some double hung windows may be specifically designed to meet egress, most are not. When you open one panel, the large glass panel size that is left doesn’t allow for a person to crawl out. So if you have this window style, you may need to replace a few.
Similarly, awning windows often don’t open wide enough to meet the requirements. So you may need to invest in casement or sliding windows for your home.
What If My Property Already Has Plenty of Large Windows Upstairs?
Your existing bedrooms and living areas already have a rescue window opening. That’s because it’s easy to have a large enough bedroom window with so much available wall space. However, since your basement is underground and lacks room for large windows, there needs to be an escape route other than the door leading up to the stairs if you plan to convert the basement into a living area.
Getting Your Egress Windows
The difference between having a safe, habitable space and breaking your local building laws is only a matter of a few inches. So make sure that your home is properly equipped for any emergency. Large egress windows are simple to install and keep you and your family safe!