Make sure you have a permit.
Just like structural demolition, most cities require a permit for interior demolition projects. Generally, the contractor you hire to do the work will gather any necessary permits for you, but don't assume that's the case. Be sure to discuss and confirm this with them before any work begins (preferably before hiring them). Permits are usually acquired from your local Buildings Department and are essentially a means of acknowledging that you will perform the demo in accordance with local protocol.
If asbestos is present in the home, that typically requires an additional permit for the abatement and removal process. Our Homeowner's Guide to Asbestos explains everything you need to know.