I am looking at buying a new house that is already under construction. The only thing is when I looked down into the basement (no stairs down yet) the slab had not been put in yet. The walls on the home are already framed up.

Should I be concerned about this or is this the normal way that basements are constructed in New England? The home is going to have a slab in the basement, but how will having it put in later affect the house and the basement?