Don't want to see the rest of the model through the windows/doors

I can understand why you might want to do something like this. In the very early stages of design you might cut openings in walls but not yet want to spend time populating them with windows. So you have a hole with nothing in them and inevitably then see whatever goes on in the background.

Funnily enough, this very subject came up in another recent post with another workaround involving an extension: Depth of section cut