Now that the walls are pretty much complete, it's now time to come to the windows. I drew in the window shapes when I drew the elevations for the wall sections, basing them on a sash window design. I'm lucky enough to work at a company with access to a vinyl plotting cutter, so having drawn out the window and door frames, I then output the files using the vinyl cutter onto a matt white vinyl. This was then applied to a piece of semi flexible CD case material and then cut out with a sharp scalpel to the outside edge of the frame (The door frames were applied to a piece of 1.5mm cardboard)
Test fitting showed that a little shaving of the inside of the window apertures was necessary, but much better to do this now, rather than after the model is painted.
The windows have now been taken out and the inside of the apertures were then scribed as necessary, ready for a coat of paint before gluing in permanently. Now I know all the windows and doors fit, it will be much easier to paint the walls with the windows removed, then they can be glued in once dry. Of course a little touching up may well be necessary, but hardly a hardship with a fine brush.