Basement Egress Window Requirements Explained

If you're putting a bedroom in your basement, you need an egress window. It's not optional - it's building code, and it's about safety. Here's what you need to know.

What Is Egress?

"Egress" just means "a way to get out." If there's a fire and the stairs are blocked, people sleeping in the basement need another escape route. That's what egress windows provide.

When Do You Need One?

You need an egress window in:

• Any basement bedroom
• Any basement room someone could sleep in (even if you call it a "den")

You don't necessarily need one for a basement family room or office, but it's not a bad idea anyway.

The Requirements (IRC Code)

Minimum opening dimensions: - 20 inches wide minimum

• 24 inches tall minimum
• 5.7 square feet of opening area

Note: The opening area is the key. A 20" x 24" window is only 3.3 square feet - not enough. You need at least 5.7 square feet.

Maximum sill height: - 44 inches from the floor

If the sill is higher, you need steps or a platform inside.

Window wells (if below grade): - At least 9 square feet of area

• At least 36 inches from the wall
• If deeper than 44 inches, needs a ladder or steps

Common Window Sizes That Work

• 24" x 36" = 6 sq ft ✓
• 30" x 32" = 6.7 sq ft ✓
• 36" x 36" = 9 sq ft ✓

Go bigger if you can - they let in more light and are easier to escape through.

The Installation Process

1. Design and get permits
2. Excavate outside for window well
3. Cut through concrete wall
4. Install window frame and window
5. Install window well and drain
6. Backfill and finish

Cost

Expect $2,500-5,000 per window including the well, installed. It's not cheap, but it's required and adds value to your home.

Don't Skip the Permit

Unpermitted basement bedrooms can kill a home sale. Buyers and inspectors look for proper egress. Do it right. Planning a basement bedroom? Also read about basement lighting tips and basement ceiling options.