In this video, Matt Risinger visits Zac Thomas at his build site in Nashville, TN. Zac and his team are building a high-performance new home that has very interesting technology, including a pre-cast foundation, GeoThermal HVAC, and some cool new products from Mitsubishi. As you will see, Thomas incorporated new technology and techniques to build a more efficient, more sustainable home. This home features an 8" pre-cast, concrete wall system. Each joint is joined by hydraulic cement, which provides initial logistical issues, but comes with a 15-year water intrusion warranty, which is worth the investment.Another major benefit of the concrete wall system is that they come pre-insulated. They have about a 4" rigid foam board, which has a R15-R18 value.Each of the walls has steel hooks that interlock with the concrete slab that you fill after the wall installation, which makes for a very stable house; nothing is moving. If you're a framer, that's music to your ears!Another fabulous feature you can see in this home is that the duct work and HVAC system is within the thermal envelope of the house. The main floor is managed by a GeoThermal HVAC system, while periphery rooms are served by small, Mitsubishi units. They're small and fit right in between 16" floor joists. Tune into the full video to how efficient this home actually is (hint it's very efficient).