An important step in keeping a home warm and dry is to waterproof the exterior of the concrete foundation walls before they are backfilled (when the dirt is piled up against the exterior of the walls).
In the planning stage of this home, it was decided to put the ductwork for the lower level in the ground under the floor slab. This is laid out along with all necessary plumbing piping before soil is brought in to act as a base for the floor slab.
In addition, this home will have radiant heating in both the lower and main floors. A layer of insulation is laid before the piping for the radiant heat is snaked over the area. Steel mesh reinforcing is then added to give strength to the concrete slab. Finally, the slab is poured and all the ductwork, piping, and structural steel is safely encased and protected.