A sloping (raking) top is easy, but a sloping (raking) bottom requires more work. A sloped top can be made with a window object or a WinDoor object. But that does not answer our problem.
The answer is that we need to make a symbol for the window. We will not be able to use a standard object to make our window.
•If you change your view to look directly at the wall it becomes easier.
•The upper part of the window has to follow the upper roof and the underside of the window has to follow the lower roof slope.
•Draw lines on the roof edges and offset them. This makes guides to draw with.
•Use the polygon tool to draw the outline of the window.
•Offset the polygon.
•Make a copy of the inner rectangle.
•Exrtude the outer polygon 120mm
•Extrude the first inner polygon 125mm
•Extrude the second inner polygon 10mm.
•Move the extusions in 3D so that they are in the correct locations.
•Use the Subtract Solid… command to subtract the smaller polygon from the bigger one. This will make a window frame if you get it the right way round.
•In plan view move the glass so that it in the right place.
•Select the window frame and glass.
•Make the window in to a symbol.
•Place the symbol in the wall.
This can be done really quickly. One of the tricks to look out for is to set your view correctly. This makes all the other steps easier if you get this correct.