1. Set the window in the windows opening leveled and squared, use shims where needed.  Also ensure that the drainage holes are on the bottom of the window.

2. Verify that the sill of the window is level.

3. Verify that the frame is not too tightly or too loosely shimmed so as to avoid bowing in or out. 

4. Ensure that the space around the operating sash is uniform and parallel in order to get the full benefit of the weatherstripping.

5. Fasten with woodscrews 6” down from the top and 6” up from the bottom on vertical  members.  Larger windows may require fasteners top and bottom.

5. Pack with insulation around exterior of frame and/or caulk with a latex caulking.  Foamit  insulation is NOT recommended as it will bow the frame.

6. Install finishing trims and you are done.