The “rough opening” is the framed opening in your wall for the window to fit in. Rough openings are usually sized 1/2” larger than the height and width of the window’s frame size to allow room to shim the window in case the opening is not perfectly square. However, some manufacturers recommend a rough opening size different from this rule of thumb — consult with any member of our sales staff to verify the proper rough opening for the window you are planning on using.