Replacing an AC Unit With a Window

Build a window sash for an opening that won't fit a standard-size window.

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Filed under: Windows, How To

There used to be an air conditioner on one side of this fireplace and an ugly aluminum window on the other side. Now there are two matching hopper-style windows

If you can't find the right size window, make your own.

Tools and Materials:

hammer
chisels
miter saw
compressor and finish nailer
table saw
screw gun
two 10’ 2 x 4 clear Douglas fir for sashes
two 8’ x 1-3/8” wood trim
rail-and-stile bits
piano hinge
sash latches for casement
glass cut to fit
glazing compound
push points
wood glue

Steps:

1. Remove air conditioning unit from the wall and all related weather stripping. Repair or reconstruct the window’s opening.

2. Determine the sash size of your window and its style — casement, awning, hopper. Our window is a hopper which swings open at the top.

3. Cut the fir into four pieces creating the frame (sash) of your window. Cut a rabbet edge in all four pieces to hold the glass.

4. Use the stile-and-rail bits to cut the interlocking tongue and groove that will hold your frame together. Glue and clamp the four pieces together and allow the glue to set completely.

5. Place the window glass inside the frame. Secure the glass in place by inserting the push points. Put the spikes of the point into the wood just above the glass then use a putty knife to push the points into the wood.

6. Apply a bead of glazing compound along the seam where the wood and glass meet. Take the putty knife and run it across the glazing at a slight angle to smooth it out. This will seal the glass to the frame and make it weather-proof. When the glazing compound is dry, install wood trim over the seam.

7. Install one side of the piano hinge onto the bottom of the window frame and screw the other side of the hinge onto the window sill.

8. Fasten the sill to the window opening. Attach wooden trim pieces around the the frame to hold it in place and to help seal the it. Attach chains between each side of the window frame and the window casing (these hold the hopper-style window open). Finally, attach the latch.