This study describes the construction and evaluation of a low energy house which should be in harmony with the environment and also be assisted by hybrid natural energy resources and unused energy. An experimental house with ground source heat pump (GSHP) was built in Hokkaido University, Japan in March, 1997. As a result of experiments, it was shown that approx. 80 % of the total energy was provided from PV modules, solar collectors, underground and exhaust heat. Annual energy consumption was 12.5 % of typical house’s one in Hokkaido. This report describes an outline of the low energy house and experimental energy balance.