The first step in window installation is determining the size of the opening. If the window is smaller than the size of the opening, it is important to make any necessary adjustments. When measuring the opening for a new window, take measurements of the height, width, and sides of the new window frame. The contractor will use the smallest measurements to make sure that the windows will fit properly. Then, use an Air Shim bag to nudge the jambs into place.
If the new window will be placed in a wall, you will need to make sure the opening is level and free of obstacles. Remove all clutter from the area. Move any furniture or coverings to four to six feet away from the window openings. Trim any shrubs or landscaping to provide enough clearance for the crews. The space between side jambs should be about two feet. A bow or bay window will require even more clearance. A drop cloth will help protect the surrounding area.