Egress window cost

An egress window costs $3,000 to $8,000 installed, typically around $5,000. In an existing concrete foundation wall that means cutting the concrete, excavating outside, setting a window well and building a drain, which is why it costs ten times what the window does.

It is required for any basement room used as a bedroom, and it is what makes the difference between a bedroom and a "bonus room" in a listing.

What it costs

What the code requires

The numbers are consistent across most of the country:

The net clear opening is the actual hole a person passes through with the window fully open, not the window's nominal size. A casement window achieves it in a smaller unit than a slider, which is why most egress windows are casements.

A window that satisfies the area but is only 18 inches wide fails, because both the minimum dimensions and the total area must be met.

The drainage is what fails

A window well is a hole in the ground against the foundation. Without drainage it becomes a bucket, and a full window well against a basement window is a guaranteed flood.

A correct installation has:

• A drain in the base of the well, connected to the footing drain or to daylight
• Gravel in the base rather than soil
• The well extending above grade by a few inches so surface water does not run in
• A cover or grate, which keeps out rain, leaves, children and animals

A well with no drain and no cover is the most common defect, and it is what turns an egress window into a water entry point.

Is it worth it

For a legal bedroom, it is not optional. An unpermitted basement bedroom without egress is a safety problem, an insurance problem and a disclosure problem at sale.

For the value: converting a basement room into a legal bedroom typically adds more to a house than the $5,000 costs, because bedroom count is one of the fields buyers filter on and appraisers count. A three-bedroom house becoming a four-bedroom house is a category change.

It also improves the basement enormously in daylight terms, which is worth something on its own.

Frequently asked questions

Can I put a bedroom in a basement without one?

Not legally in almost any jurisdiction, and it is a genuine fire safety issue rather than a technicality. Basement fires block the stair, which is the only other way out.

Do I need a permit?

Yes. It cuts a structural wall, and it is inspected for the opening dimensions, the lintel and the well drainage.

Can I cut the opening myself?

Cutting a large opening in a foundation wall is structural work needing a concrete saw and a lintel designed for the load above. It is not a DIY job, and doing it wrong compromises the wall.

How long does it take?

One to three days for the cutting, excavation and installation, plus the inspection. Interior finishing afterwards.

What about an egress door instead?

A walk-out or a stairwell to grade satisfies the requirement and costs $6,000 to $15,000. It is a much better outcome where the grade allows it, because it makes the basement genuinely usable and adds a second entrance.