The relationship between the four elements of passive solar design for small buildings; south facing windows, thermal mass, thermal insulating shutters, and insulation thickness, were studied by computer simulation to determine their long-term effects on energy consumption. Solar and weather data for Fairbanks, Alaska, 65(degrees)N latitude, was the input to the TRNSYS Program used to perform the dynamic simulations. Results for an entire heating season are presented. Overall it is shown that shutters and insulation are the most important elements in the design of energy conserving structures for the north. Thermal mass plays a lesser role, especially during the mid-winter months when direct solar gain is balanced by the building envelope losses