Debbie, It all depends on where you live. I'm from the northeast and I hardly see slabs for foundations because of thr freeze/thaw cycle here. If your from the south where there is little chance for freeze/ thaw the slab will work fine. However if your from the north you must build a foundation with footings below the frost line. One advantage if your from the north and must build a foundation, you can build a crawl space and save about 1/3 fo the cost of a full foundation.