The reason there are basements in the north is because of the freeze level. Up north the freeze level may go down over four feet. The foundation must go below that. So if the have to dig out that much, they may go a bit deeper and make basements or even rooms. In the Memphis area the freeze level is about 18 inches. So its not necessary to go that deep. Saves money and we get more housing above. Ask a home builder.
Sellers Agent Realtors
Soil in the Memphis area does not drain well. Basements are prone to water problems in this area. Most homes built after WWII don't have basements. Mike Ward, Crye-Leike Realtors (901)766-9004, (901)277-3869 (direct). Call me if I can help in your search. I am a lifelong resident of the Memphis metro.