Egress windows - and who should really be cutting your foundation

What is egress window installation?

An egress window is a basement or bedroom window large enough for someone to climb out of in a fire and for a firefighter to climb in through. Most residential codes require one in every sleeping room, which is why finishing a basement into a bedroom usually triggers one. The window is the small part of the job: the work is cutting an opening in a concrete or block foundation wall, excavating outside for a window well, and getting the drainage right so the well does not become a bathtub against your foundation.

Signs you need egress window installation

• You are finishing a basement and any part of it will be used as a bedroom - this is the single most common trigger, and it applies whether or not the room existed before
• You are selling and an inspector or appraiser has flagged a basement bedroom as non-conforming
• The basement has only a small hopper or slider window that nobody could climb through
• An existing egress well is filling with water, has no drain, or has a cover that cannot be opened from inside
• You are converting an attic or garage into a sleeping room, which carries the same requirement
• You want a basement to feel like living space rather than a basement, and light and a real exit are what is missing

Seeing something not on this list? Browse windows problems by symptom →

How egress window installation actually works

1. 1

   Confirm what your jurisdiction actually requires

   Residential codes regulate a specific set of dimensions for an emergency escape opening: a minimum net clear opening area, a minimum clear width, a minimum clear height, and a maximum sill height above the finished floor. Window wells have their own required dimensions, and deeper wells require a permanently attached means of climbing out.

   Watch forAny figure quoted to you from a contractor’s blog, including ours. Codes are amended locally and revised between editions. Your building department is the authority, and the numbers they enforce are the only ones that matter - get them in writing before anything is ordered.

2. 2

   Site assessment, before a price exists

   Wall construction (poured concrete, block, or a preserved-wood foundation), wall thickness, what is buried outside, where the utilities run, how deep the basement sits, and where water goes today. Access for a machine matters too - some sites are hand-dug.

   Watch forA price quoted over the phone from a photo. Foundation type and excavation access are the two variables that move this job most, and neither is visible in a picture of the inside of your basement.

3. 3

   Permit and structural detail

   Cutting a hole in a load-bearing foundation wall is permitted, inspected work. The opening needs a lintel or header sized for it, and in block walls the cut cores near the opening are typically filled. Some jurisdictions want an engineer’s detail.

   Watch forA contractor offering to skip the permit. An unpermitted egress window is worse than no egress window at resale, because it is a visible alteration that fails inspection instead of an absence nobody documented.

4. 4

   Excavation and the well

   The outside is dug out to below the sill, the wall is saw-cut, the opening is framed, and the well is set and fastened to the foundation. Backfill goes in compacted, and the grade around the well is shaped to send surface water away from it.

   Watch forA well installed with no drainage. A window well is a hole against your foundation that collects rain - it needs a gravel base connected to the footing drain or to a dedicated drain, or you have built a reservoir and put a window at the bottom of it.

5. 5

   Fitting the window and closing up

   The unit goes in, is flashed and sealed, and the interior is framed, insulated and finished. The window has to actually open to its full rated dimension without a tool, a key or special knowledge.

   Watch forA unit whose net clear opening was calculated on the frame size rather than the actual clear opening when the sash is fully open. That difference is what fails inspections.

What does egress window installation cost?

Egress work spans a wide range because the window is a small fraction of it - excavation access, foundation type and thickness, well depth, and drainage decide the number. A hand-dug opening in a thick poured wall on a tight side yard is a different job from a machine-dug one. The cost guide separates those.

See the full egress window installation cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →