Two super-insulated contemporary residences constructed in 1992 in different climatic regions had the same designer, followed the recommendations of the Alaska Craftsman Home Program and have identical envelope details. One located on a mountainside in Anchorage, AK, has a 180 m2 floor area and 6100-degrees-C heating degree-day winters while the other with 128 m2 is a Lebanon, CT, with 3400-degrees-C degree-days. The walls are 29 cm thick (R = 7.2 m2 K/W) and insulation in the roof is 61 cm thick (R=13.2). Wall construction minimizes thermal bridging and includes a vapor barrier and a polyester fabric air barrier. The Alaskan residence has floor heating while the Connecticut house has baseboard heating, supplied from gas and oil-fired boilers respectively. Both houses have mechanical ventilation with heat recovery and substantial window areas on the south sides for solar heating assistance. The energy consumption normalized for area and weather differences is about 30% less for the Alaskan house. About half of this difference is due to a less-efficient boiler, a quarter to the proportionately smaller roof and the remainder to increased air leakage of a fireplace and additional entrances of the Connecticut house. The Alaskan residence won the 1992 Governor＇s Award for Excellence in Energy Efficient Design.