Adding an Egress Window to Basement

by Mike
7 Materials
12 Hours

While in the process of finishing our basement we decided to add an additional bedroom to the space. In order to consider this a bedroom we must first provide a secondary exit point for safety. By eliminating the sealed glass block we can do just that.

The beginning. A simple basement glass block window with a simple window well to start with.

New window was purchased to determine the size of the new opening. Always remember to account for new frame in addition to window size before cutting opening. Start off by removing glass block in my case this was done with a sledge hammer. Then dig the window well. Your window well should be about a foot below your new window opening. In my case I went about 18 inches below.

After cutting the existing foundation and block using a concrete saw I carefully removed all pieces. My first cut did not go all the way through so I had to make an additional cut from inside. Next step was to assemble new window frame using 2x12 pressure treated wood. With frame installed I test fit window to check clearance.

All gaps were tight once installed however I still added a little expanding foam insulation for added protection.

All then trimmed out the window using outdoor PVC molding and caulking in all seams to waterproof the new window.

Using additional 2x12 pressure treated lumber I was able to build a new window well that also provided an additional step to make getting out easy if needed. Also backfilled this area with about 6-8 inches of river stone to provide plenty of drainage. My purpose for originally digging a little deeper than needed.

Once set in place and leveled I then added outside frame and back filled with fresh topsoil.

View from inside the unfinished basement. Now time to build some walls and move on to the next part of this project. Also remember to add some type of alarm or security features as this will also provide an access from the outside.

Suggested materials:
  • 2 8 ft 2x12 pressure treated   (Home Depot)
  • 1 4x4 10 ft pressure treated   (Home Depot)
  • 1 sliding egress window   (Home Depot)
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Frequently asked questions
Have a question about this project?
  2 questions
  • Linda Ross Linda Ross on Dec 26, 2020

    How far from the floor is the lower sill? It looks like one would need a step ladder to use the egress.

  • Mary Paradowski Mary Paradowski on Jan 22, 2021

    is an average size adult able to use this window? In our area window must be at least four feet tall. Over all look is great but not very useful. Would not pass code and basement cannot be used for bedroom without approved window.

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3 of 5 comments
  • Aimee Aimee on Dec 28, 2020

    Great job!

    • Mike Mike on Dec 28, 2020

      Thank you makes a big difference

  • Melissa Hirt Melissa Hirt on Dec 28, 2020

    This is NOT an egress window. It needs to be 5 square feet of clear opening. Plus it needs to be lower to the floor...I believe no higher than 42” (I’d have to double check that number)