With the insulation, vapor barrier and rebar in place, the footings and slab were poured on the Ashtree Passive House. The slab is a thickened-edge design that allowed for a monolithic pour, seen in picture 1. Once the perimeter forms were removed, 6" of EPS foam was glued to the exposed concrete edge to complete the foundation insulation (picture 2). The EPS geofoam provides R-26 insulation below the slab and was used to create thermal breaks between the garage and exterior retaining walls (picture 3). The thermal breaks prevent cold diffusion through the uninsulated garage and retaining wall concrete, which helps keep the house warmer and lowers the energy demand for the home.