How to Make Inexpensive Storm Windows Using Plexiglas

Written By
Dario Saandvik
Dario Saandvik
Published: May 29, 2010
Updated: Nov 20, 2021
2 minute read

However, for older houses with wooden framed windows and no storm windows, having storm windows professionally retrofitted can be very expensive. Luckily, there is a fairly cheap and uncomplicated way to create your own storm windows from Plexiglas.

Things You Will Need

  • Tape measure
  • Utility knife
  • Plexiglas sheeting (acrylic, polycarbonate, Lexan, etc.)
  • One-by-two inch lumber
  • Miter saw
  • Router
  • Staple gun
  • Silicone caulk
  • Adhesive-backed foam weatherstripping
  1. Measure your window frame(s). You will want your storm window, including its wooden frame, to be about 1/8-inch smaller on all sides so that it can be held in place by the foam weatherstripping.

  2. Cut four pieces of one-by-two lumber to fit the four sides of your window, less 1/8-inch.

  3. Miter the ends of the lumber with a 45-degree miter cut on your saw.

  4. Rout a line 1/4 inch deep and as thick as your type of Plexiglas on the inside edge of each piece of wood.

  5. Cut your Plexiglas sheet to fit inside the wood frame, adding 1/4 inch on all sides so that the sheet fits perfectly in the routed groove of the frame. Cut the Plexiglas by scoring it deeply on both sides with a utility knife. Then place the scored line directly along the edge of a table, and break the Plexiglas along the line by pushing down firmly.

  6. Insert the cut Plexiglas into the routed grooves in the frame. After the frame is assembled around the Plexiglas, staple the corner joints.

  7. Apply silicone caulk along the inside edges of the frame on both sides of the window and allow to dry according to the caulk manufacturer's specifications.

  8. Place lines of adhesive-backed foam weatherstripping inside the window frame, and then push the Plexiglas storm window into place. The foam will hold it up firmly, and you can remove it when the weather changes or when you wish to open the window.

The Drip Cap

  • Storm windows are an important part of insulating your home against adverse weather and heat or cold.
  • Measure your window frame(s).
  • Cut your Plexiglas sheet to fit inside the wood frame, adding 1/4 inch on all sides so that the sheet fits perfectly in the routed groove of the frame.
  • The foam will hold it up firmly, and you can remove it when the weather changes or when you wish to open the window.
Dario Saandvik

After working as an editorial assistant for the University of Chicago Press, Dario Saandvik began writing in 2009. He specializes in gardening, home maintenance and computer software. Saandvik has a Bachelor of Arts in English from the…

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