How to Install Glass in an Exterior Door

A good, solid exterior door serves a great purpose by saving money on utility costs.

Diamond shaped glass.Diamond shaped glass.
However, if the door has no window, it doesn’t serve the potential it can. To be able to see the postman when he walks up or the blue sky on a sunny day, or even to add beauty to the door by adding beveled glass, installing glass in an exterior door is a project that do-it-yourself homeowners can tackle with confidence. In preparation for this project, you need a little information. Exterior doors are 1 3/4 inches thick. Double-pane insulated windows are about a half inch. The 3/4-inch outside corner mold has an inside measurement of 5/8 of an inch. The outside corner mold will allow a half-inch space to insert the glass.

Draw the desired shape of the glass on the exterior door using the carpenter’s square. Score the line with a utility knife. This prevents splintering of the wood.

If the desired hole is large enough, cut the straight lines with the skill saw. Set the depth of the blade as needed to cut through the door. Align the blade with the line, set the front edge of the saw flat against the door, and slowly lower the back of the saw through the door. Stop short of the corner, and withdraw the skill saw.

Cut the remaining line with the jigsaw making a clean corner. Be certain that the cut is smooth all the way around its perimeter.

Measure and cut the outside corner mold to fit in the hole like a picture frame for both the inside and the outside of the door. One leg of the outside corner mold will slide into the hole cut for the glass. Secure the “picture frame” mold with the 4d finish nails.

Apply a bead of caulk to the inside of the corner mold so the glass will seal between it and the mold. Insert the glass into place. Apply a bead of caulk against the glass. Install the outside corner mold on the outside of the door with 4d finish nails.

Things You Will Need

  • Measuring tape
  • Pencil
  • Double-Pane Insulated Glass
  • 3/4-inch outside corner mold
  • Utility knife
  • Hammer
  • 4d finish nails
  • Nail set
  • Drill
  • Drill bit
  • Electric Miter saw
  • Skill saw
  • Jig saw
  • Carpenter’s Square
  • Silicone Caulk
  • Caulk gun


  • Always wear safety glasses.
  • Be certain the exterior door is laying flat and cannot move while the cuts are being made.


  • Never leave electrical tools unattended.
  • Do not set the depth of the skill blade any more than needed to make the cut.

About the Author

Michael Straessle has written professionally about the construction industry since 1988. He authored “What a Strange Little Man,” among other books, and his work has appeared in various online publications. Straessle earned a Bachelor of Arts from the University of Arkansas at Little Rock in professional/technical writing.