Editing Double Awning Window

I am putting in 'Double Awning' windows, but by default the two panes are each half the height of the window. I need the top (opening, hinged at top) pane to be a lot smaller height-wise, maybe 25% of the whole. I've searched the manual and this forum, have tried the Windows dialogue and handles in 3D Vector view, but no joy.

Think I must be missing something very basic here? :confused:

Andy

You might need to place to single windows, one above the other, and size them accordingly. Then position them very close so that they mull together.

Thanks Elovia, if that's what I have to do, then so be it.