It wouldn't be part of the foundation then. So there is a big difference between floors and foundations. Foundations carry the load of the structure. If you just have a 2 inch slab and it's not connected to the walls it's not part of the foundation. You'd best go down to the planning office and get your blueprints and then go to whoever approves building permits and ask them what steps you need to do to follow code. This isn't something you want to wing or guess at.