How to Replace Metal Basement Windows

One common form of basement window is a metal casement in which the pane flips open inward. Replacing these windows once they're worn or outdated is among the easier window-replacement projects, because the windows are pre-hung, coming out and going back in all at once instead of in sections. Also, they're likely the smallest and least-visible windows in your home, making them a great practice project before you move on to replacing the bigger windows.

  1. Measure the basement window opening with the old window still in place, measuring the height and width from the edges of the metal casing where it meets the frame. Order your new window with those dimensions. Leave the old window in until the new one arrives.

  2. Pry out the interior border of trim from the edge of the window opening, using a pry bar and hammer. Don't break the trim. Set it aside.

  3. Run a reciprocating saw's metal-cutting blade around the edge of the window, in the spaces exposed by the removal of the trim, to cut through the screws holding the casing in place. Pull the old window unit into the room. The opening should be clear except for a border of trim around the outside of the opening. Leave that trim in place.

  4. Set the new window unit in the opening, pushing it back until it is against the exterior trim. Hold a level against the unit and insert shims around it to get it square. Secure it with mounting screws through the holes in the sides of the unit.

  5. Shoot foam insulation into the gaps around the edges of the window, filling the gaps completely.

  6. Put the trim back in place that you removed earlier, using your hammer and finishing nails. The trim should hide the gaps and pin the new window in place. Caulk around all the seams at the edges of the new window.