How to model the interior of a building, inside the actual building Let's say that I want to model the interior of a house, inside the house. By this I mean that I have a scene where the outside of the house is modelled but the inside of the house also needs to be modelled. What is the practical method to do this?

What is a practical/accepted method of doing this?

Should I cut away some of the walls? (but then, how do I render from a viewpoint that should include the walls that have been cut away?)

Is there some other clever method to do this?
I'm not sure what exactly you are trying to do but I think this might help:

You can "hide" the walls by selecting them and pressing "H". Then you can place your models inside the building. Also, you can make use of the "Wireframe" mode. Just press "Z".

I hope this helped. :)