What is an Egress Window?

If you have been looking for ways to make your home safer or add value and marketability to your property, you might have come across the suggestion to add an egress window to your basement. So, what is an egress window, and should you install one in your basement?

What is the purpose of an egress window?

An egress window is a window that also serves as an emergency exit. They are usually a requirement for converting your basement into a living space while keeping your house up to code. Even if they are not a requirement, they are an important safety feature. They can also bring a lot more natural light to a basement space, and make it feel more welcoming and less of a utilitarian space.

Egress windows are required if your basement contains a bedroom or any other living space such as a TV room, office, or workshop.

Egress windows are not just for basements though. Any window that meets all of the necessary requirements set out by the housing code can be considered an egress window, adding value to your property. Besides basement living spaces, the housing code also requires any bedroom to have an egress window, and attics that have been converted into living space must also have an egress window.

What does it mean when a window does not meet egress?

Windows have to meet certain specifications to be considered an egress window. In older homes where the basement was not originally intended to be used as a living space, the existing windows are usually too narrow or do not open wide enough to allow a person to escape, or for a first responder to get inside.

Housing code for egress windows

The International Residential Code provides some simple guidelines on installing a safe egress window. Always check your local house code too, as it may have additional requirements. According to the International Residential Code, all egress windows must have:

  • An opening that is at least 20 inches wide

  • The opening must also be at least 24 inches tall

  • The net clear opening space (the width multiplied by the height) must be at least 5.7 square feet

  • The sill of the window must not be more than 44 inches above the floor of the basement

Many basement windows can meet the first 2 requirements without qualifying as egress windows. Remember to calculate the net clear opening space and measure the sill height if you are not sure why your basement window does not meet egress window standards.

Can you have an egress window that is below ground level?

All of the above rules assume that your basement window is above ground level. If your basement window is below ground level, there are additional requirements for it to be considered an egress window.

The main additional requirement is that there must be a well dug down to below the exterior window frame of the basement window. The well must be at least 36 inches wide and 36 inches long. If it is more than 44 inches below ground level, you must also build steps or a fixed ladder. Each step or rung of a ladder must be at least 12 inches wide, and ladder rungs should not project more than 3 inches from the wall of the well.

You can decorate this area with potted plants and ornaments if you want, as long as it does not obstruct the exit path or the opening of the window itself.

The basement window can be positioned below a deck or porch, but only if there is enough room for an average adult to get out. There should be at least 36 inches of clearance between the top of the window sill and the bottom of the deck supports.

Are the measurements the only egress window requirements?

Basement egress windows must serve as a way out for your family in the event of an emergency like a fire. They must also serve as a possible entrance for first responders to enter, for example, if they need to rescue you and cannot use any other entrance. Think about whether a firefighter in full kit would be able to get through the window easily.

As a result, it is important that the window can be opened all the way, without the window sash getting in the way or any other obstructions. It must also be possible to get out from the inside without the use of keys or tools. Besides the window itself, this also covers any screen, grill, or bars that cover the window.

Are casement windows basement egress windows?

Casement windows swing open sideways, like a door. This means that can provide a wide opening and easy exit even if you only have limited wall space to install a window. However, they do require more clearance space on the exterior side of the window due to the way the window swings open sideways.

Can a top hung window be used as a basement egress window?

There are no rules saying that a top hung window cannot be used as a basement egress window, it is often not the safest or the most practical option. While it does have the advantage of not needing any extra clearance space for a swinging window on the exterior of the building, there are a few potential complications to consider.

Only half of a top-hung window can be open at a time, which means the window needs to be twice as tall to serve as an egress window. This could require you to dig a well on the outside of the building to accommodate the lower window sill, depending on the ceiling height of the basement. It also means that you will have a window that spans most of the vertical height of your basement, which may not be very visually pleasing depending on how you are able to construct the well on the other side.

Why add an egress window to my property?

There are a few reasons to convert an existing basement window into an egress window. Safety is the first and most important reason. Egress windows provide vital escape routes in the event of a fire, flood, or other natural disasters.

Adding an egress window can also enable you to turn more areas in your home into living spaces, such as the basement. Converting an existing basement window into a basement egress window, or building a new egress window where there was none, can also allow more natural light into your basement, making it a more pleasant space to be in.

Finally, egress windows add value to your property. Not only do the egress windows themselves add value, basement conversions and other home renovations that they enable can also add a lot more value to your property. If you want to advertise your property as having a basement living space, it has to have a basement egress window.


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