We just bought a new 3300 sqft 2-story house from David Weekley.
And recently we found out they are using only one AC unit (5 tons) for the house. We feel really suprise becasuse we saw most of new houses at this size have 2 AC units. We checked our contract with the builder, and there isn't any word about AC. We also discussed with the bulider, and they said this design past some model-based performance test, so they chose one unit.
All the model homes from this builder using 2 units, even for one story home (~2500 sqft).

We are worrying about the quality and efficieny of this design, and also we heard that one unit will produce a bigger eletric monthly bill for us. The new house is almost done, so it is very difficutl to change to 2 units.

Can anybody help us on this to give a professional analysis or conclusion?
If it does make big difference or affect the re-sale value very much, we might return the house to the builder.

Thanks a lot.