Rough Opening: The size of the framed window opening, from stud to stud and header to sill. When ordering with Rough Opening size method – your windows exact size will be ½” smaller to allow a ¼” gap around the perimeter of the window between the window and the framing. Example: A window ordered as Rough Opening 36 x 48, the window would come exact size 35 ½ x 47 ½.
Exact Size: The actual size of the window frame.
We ask this question to make sure that we are offering the relevant Energy Package based on your elevation. Capillary tubes are required for elevations above 5500’ due to the change in air pressure associated with the increased elevation from where the windows are manufactured. Capillary tubes are very small tubes that are inserted between the two panes of glass and allow the air between the panes to equalize to the change in air pressure. Unfortunately, argon gas cannot be used along with capillary tubes, and thus argon is not available in elevations above 5500’.
