When ordering screens, take the reveal sizes (as shown above) and the opening sizes (as shown below.
If the screen is to be fitted into a recess, only the reveal sizes will be required.
However, if you are fitting the screen to the face of the window frame you will need to provide both the reveal sizes and the opening sizes. Please study the four options below to decide which opening size category your window(s) fit into....
1. If you wish to fit a screen over a single opening window in a row or group of windows, or an opening window next to a fixed pane, take the reveal sizes as being the maximum frame sizes of that window, and not the entire reveal.
2. If your window has a surface-mounted vent at the top, you can either remove this or mount your screen just below it, in which case the reveal height size will be from the bottom of the vent down to the window sill.