If it can be helped - do not live in the house during the demo.In the case that it is a partial tear down it is usually a good idea to take the walls down to the studs. You never know what kind of garbage can be hidden or let behind from previous remodels etc..Be prepared - Majority of folks that begin the demo end up demolishing twice what they ever thought they would to begin with. This is nothing to be alarmed by, it happens that once you have walls down and things are opened up you actually get more insight into how your place was originally built. In some cases it makes more tear down necessary after you see what lies beneath.