How to Cut a Basement Wall Egress Window

Determine the placement for the egress window from the outside. Drill a 1/4-inch pilot hole through the wall with the long masonry bit in a hammer drill. Go inside and check that the window placement doesn't interfere with any plumbing pipes or electricity wiring.

Go back outside. Dig the window well with the shovel. Make the hole 6 inches deeper than the rough opening's length and at least 48 inches square.

Mark the rough opening's outline on the wall's exterior side, using a tape measure, level and chalk. Drill 1/4-inch pilot holes through the outline's two bottom corners and return inside.

Draw the rough opening's outline on the wall's interior side, using the pilot holes as reference points. Cut along the outline with a 14-inch diamond blade in a concrete saw. Make the first pass about 1/4 inch deep and concentrate on making the cut as accurate as possible.

Make a second pass around the rough opening's outline, using the first pass as a guide. This time cut about 1 inch deep in a concrete block wall or 3 inches deep in a solid concrete wall.

Go outside and repeat steps 4 and 5 along that outline, then return inside. Hit the wall within the rough opening with the sledgehammer to knock it out. The wall will knock out in sections and should break away evenly along the lines you scored.

Clean up the rough opening's edges with the chisel and hammer. Position the chisel against a rough area and hit the handle with the hammer to smooth it.