Not all demo work requires the heavy hand of a sledgehammer. You can do some serious damage to your gas, water and cable lines if you go in swinging. Buy a few different screwdrivers to help with the more delicate work. Taking apart electrical outlets and switches is always the first part of a wall demo and you can't do that with a sledgehammer. Screwdrivers are also good for taking up small pieces of wood flooring and tile when you aren't removing the entire floor. Buy a long flat head, a standard-sized flat head and at least one Phillips head screwdriver. That should cover you in most situations. The chisel ends of the flat head screwdriver can act like a small, lightweight pry bar as well.