b'Frame DepthMetal Window Finned2 to 2-3/4 Wood Window SteelCommon Window 3-1/2 Overall CasementFrame Depth 3-1/2 2 to 2-1/2 WindowPocket Setback 2 to 2-14Frame DepthWoodWindow4-9/16FrameDepthThe importance of proper measurement must also If the old window and trim is removed down to take into account depth, because the depth of the the rough opening, the replacement window will opening after removing the old window, will deter- be as big as possible to fill the opening. This can mine the order size of the window and the methodbe important because the bulkier frame material of installation and requirements for finish trim inside for modern replacement windows tend to reduce and out. the glass area that is not always desirable to the Standard 2 x 4 construction, with sheathing on the consumerespecially for smaller windows.exterior and wall board or sheetrock on the interior If the trim remains, then the replacement window has, for the most part, standardized measurements. will need to fit to it, altering and probably increasingFrom the outside surface of the sheathing to interior the needed work to install the new window.surface of the wall, the default dimension will beIf the old frame is left intact the new window needs to4 and 9/16 inches. butt to it, fit inside it, or sit on top of the frame; againThe residential window universe consists of three influencing the cost and complexity of the installationbasic window frame materialspretty muchof the new window.distributed evenly when it comes to existingThe illustrations show common existing conditionswindows needing replacement: Wood frame,for old windows to be replaced. The next illustrationsMetal frame (steel and aluminum), and Vinylshow the various openings after either partial or fullframe (similar with composites). removal of the old window. Window size is influenced by whether the old window Whatever method is chosen, proper installation isand its trim is removed down to the rough opening; possible remembering to accommodate the water,or if the window is removed and the old trim remains; moisture, air, thermal and vapor barriers. Best or if the old frame of the window remains and only practices for all are covered in detail throughout the operating and glass panels are removed.this manual.Window Fitters Guide to Window Installation262020 AWDI, LLC Do not reproduce without permission'