Located within the sauna, but fed from the ski-waxing area, a small, efficient woodstove provides the heat. The two walls closest to the stove are a "heat-sink" filled with rocks. The floor under the stove is a concrete hydronic slab which helps to retain heat. Heat can be shared with the entire structure by turning on the digitally controlled fan system. This fan drives air from the sauna into the auto shop. A second exhaust fan, located above the sliding garage door, relieves excess heat and auto fumes to the outdoors. The sauna door can simply be left open to heat the loft. A gravel-lined air duct system runs from beneath the sauna floor to the storage closet at the rear of the building. This duct system draws fresh air into the sauna through the slatted wooden floor. Outdoor air from the north end of the building refreshes the sauna, clears auto fumes in the garage, and exits through the south end.