I understand that houses are being made with concrete/foam block walls. This newer technology increases the energy efficiency, security and strength of houses. This new design is part of a construction method called stay-in-place-forms or insulated-concrete forms.
This construction creates one of the strongest and most energy-efficient houses that are possible today. The walls can resist hurricane force winds. Concrete itself is not a good insulator. When the concrete is encased in foam, you gain energy efficiency. The concrete itself provides the strength and helps reduce the amount of noise that penetrates the walls of the house.
Energy efficiency is enhanced when air leakage in and out of the house is reduced. Since the house is built with concrete, it will remain airtight over time since concrete does not settle. While the walls will be thicker than normal, this wont be noticeable. Should you look closely at the window and door openings, you will see they are slightly wider.
Currently there are several designs of houses available. One company has a system you can use for floors. The cost will be determined by the quality of the insulation...