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What Are Egress Windows?

What Are Egress Windows?

Does My Des Moines Basement Need Them?

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

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

Basement bedrooms and living spaces need to have egress windows. Living spaces can be offices, TV rooms or workshops. This requirement also affects unfinished basements.

Why Are Egress Windows Important?

Basement fires are common, with firefighters responding to about 6,500 of them in the U.S. annually.

You don’t have much time to flee a house fire. It can become deadly in as little as 2 minutes and overtake a home within 5 minutes, according to the National Fire Protection Association.

When you only have minutes to leave, correctly sized egress windows are a crucial secondary exit.

Basement Windows in Older Homes May Be Too Small

Basements in older homes were not created to be sleeping or living areas. This is especially true for homes built before World War II.

Homeowners back then used this style of basement for utility space, laundry and storage.

Depending on its age, your home may have preceded today’s egress window requirements. Or it may have windows with a shorter opening.

If you have an older home, there’s a good chance it has short windows in the basement. Also referred to as hopper windows, these above-ground windows open inward to circulate fresh air.

But these windows are small—too small for an adult or fully-equipped first responder to climb through.

How to Measure Your Basement Windows

Not sure if your present 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 bigger windows installed.

Requirements for Egress Windows in Basements

Building codes mandate the size of basement windows. This allows for a quick 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.

What if My Basement Windows are Below Ground Level?

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

Using timber or concrete blocks in the well makes it easy to put in steps. Plus, you can add several small landscaping features, like crushed rock or potted plant.

It's OK for basement windows to be under a deck or porch. But there should be enough clearance for an average-sized adult to get out.

There should be at least 36 inches between the top of the window well and the bottom of the deck or porch joists.

Other Requirements for Egress Windows in Basements

Because basement windows are an escape route, they must open from the inside. Any screens, grilles or bars need to be taken off from the inside without keys or tools.

It’s also important that basement windows can open entirely. The window sash shouldn’t obstruct the opening. This helps your family to quickly exit—or first responders to quickly enter.

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

Choosing Basement Egress Windows

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

Casement Windows

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

Casement windows open by rotating a handle. Pella® casement windows use a crank that folds away. That way, the crank won't disrupt shades.

This window must have at least 8 square feet of net opening.

Sliding Windows

Sliding windows are great for adding more light to big basements. These windows have to be larger, because the opening is only half as wide as the window. This is due to the sash, which slides horizontally.

Sliding windows open by moving the sash from left to right. Some Pella models feature extra-durable tandem nylon rollers. These rollers give even more effortless operation.

This window must have at least 16 square feet of net opening.

Talk with the Professionals at Pella of Des Moines

Basement escape windows are a necessity for downstairs living spaces. They can be lifesaving equipment in an emergency. Meet with our professionals at Pella of Des Moines. We can help when you're remodeling your basement.

We can also recommend the right window that matches your project, budget and local egress requirements.

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