How to Make a Sidelight for a Door

Decide how large of a sidelight you'd like. Typically, you want one that's about one-third to one-fourth the size of your door. If your front door is 36 inches wide, you'll install a 9- or 12-inch sidelight. For this example, say you want a 9-inch sidelight.

To the left of your doorjamb, measure out 11 inches. Use the reciprocating saw to cut through the wall surface and create a hole 2 inches taller than your current door and 11 inches wide off the door jamb.

Cut down the 2-by-4s to fit inside the hole in your wall, framing the interior on the top, far side and bottom. Apply plenty of caulk to the board on the bottom to hold it in place against the floor. Use the hammer and framing nails to fasten the other boards into place against the side and top of the hole.

Apply caulk to the bottom 2-by-4. Slide the first glass block into place in the hole, pressing it down firmly on top of the caulk. Apply caulk on top of the block once it's in place and stack the next block on top. Repeat until you've filled the hole with the blocks.

Run a line of caulk all the way around the border of the glass block and the frame. Apply the caulk on the inside and outside of the sidelight. Wipe away excess caulk from the glass and wood with the damp cloth.

If you'd like to tie the old door and the new sidelight together, apply new trim all the way around both to unite them visually.