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What Are Egress Windows? Does My Basement Need Them?

What Are Egress Windows? Does My Basement Need Them?

A finished basement can be one of the easiest ways to add more space to your home. It can be a great area for another bedroom, a family room or a playroom.

As you prepare for your basement remodeling project, take into account that you may need to add larger windows. Egress windows, also known as basement windows, are large openings that provide an escape route in an emergency. They can also add natural light and make your basement feel more inviting.

Egress windows are mandated for basement bedrooms, regardless of whether your basement is renovated. They’re also needed for living spaces in basements that don’t have egress windows. This applies to offices, TV rooms, workout rooms and workshops, to name a few.

These windows are an important secondary exit. During an emergency, stairs or an above-ground basement door could be impassible. Egress windows need to be big enough for an average adult—or a firefighter in full gear—to fit through.

In brief, your finished basement won’t be fully finished until egress window installations are done.

Windows in Older Basements May Be Too Small

Basements in older homes, especially those made before World War II, were not originally created to be remodeled into sleeping or living areas. Homeowners at that time used this type of basement for utility space, laundry and storage. Therefore, emergency escape windows weren’t necessary.

If you live in an older home, there’s a good possibility it has skinny rectangular windows in the basement. Also called hopper windows, these above-ground windows open inward to circulate fresh air. But these windows are small—too small for an adult or fully-outfitted first responder to climb through.

Basement fires occur frequently, with firefighters responding to about 6,500 of them in the U.S. each year. And you don’t have much time to escape a house fire. It can become life-threatening in just 2 minutes and engulf a home within 5 minutes, according to the National Fire Protection Association.

Requirements for Basement Windows

Building codes require a basement window’s opening to be a specific size. This allows for a fast exit in an emergency.

According to the International Residential Code, basement windows must have:

  • An opening width of at least 20 inches.
  • An opening height of at least 24 inches.
  • A net clear opening of at least 821 square inches—or 5.7 square feet.
  • A sill no more than 44 inches off the floor.

Unsure if your existing basement windows meet present-day requirements? All you need is a tape measure.

  • Open the window as wide as possible.
  • Measure the width and height of the opening.
  • Multiply the width by the height.

Is your measurement equivalent to the required 821 square inches—or 5.7 square feet? If not, you need to have taller and wider windows installed.

If your basement windows are below ground level, you will need to have a well dug at the base of the window frame. This well needs to be at least 36 inches wide and 36 inches long. If the well is more than 44 inches deep, it will need a permanent ladder or steps.

It’s not complicated to add steps when you use timber or concrete blocks in the well. Plus, you can add a couple small landscaping features, like crushed rock or potted plants, to enhance your curb appeal.

Basement windows can be placed under a deck or porch as long as there’s enough room for an average-sized adult to escape. At minimum, there should be 36 inches between the top of the window well and the bottom of the deck or porch joists.

Because basement windows are an exit, they must open from the inside. Any screens, grilles or bars need to be removable from the inside. Both must be achieved without keys or tools, because time is crucial in an emergency.

It’s also vital that basement windows can fully open. The window sash, or the moveable part of the window that holds the glass, shouldn’t interfere with the opening. This helps your family to quickly exit—or first responders to quickly enter.

Local requirements for basement windows may be different. Check with Des Moines building officials to learn more about area guidelines.

Choosing a Basement Window

There are several styles of windows that work well for basements and satisfy building code requirements.

Casement windows are a good option for homeowners with less wall space. These windows operate like a door, swinging free to provide an ample opening.

Casement windows are opened by rotating a handle. Pella® casement windows feature a crank that tidily folds away so it won’t get in the way of curtains.

The minimum net opening for this type of window is 8 square feet.

Sliding windows are great for homeowners who have a spacious basement or want more light. These windows have to be larger because the opening is only half as wide as the window. This is due to the horizontal sliding sash.

Sliding windows are opened by moving the sash, typically from left to right. Some Pella models feature extra-durable tandem nylon rollers, which provide even easier operation.

The minimum net opening for this type of window is 16 square feet.

Basement escape windows are a must-have for downstairs living spaces. They can also be a lifesaving tool in an emergency. Include the professionals at Pella of Des Moines when you’re preparing to remodel your basement. They can recommend the right windows that fit your project, budget and local egress requirements.

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