Should I insulate my floor?
Floors above cold spaces—like vented crawl spaces and unheated garages—should be insulated, but don't forget about under the flooring. This will help ensure maximum energy efficiency for your home. According to the U.S. Department of Energy, it's ideal to insulate: Slab floors built directly on the ground. Is it worth insulating the floor? Generally speaking, you only need to insulate the ground floor. If you're on an upper floor, you don't usually need to insulate your floor space.