In 2005 a low-energy building was inaugurated in Sisimiut, Greenland, just 50 km north of the Arctic Circle. The 200 m2 building was supposed to be a building with an energy consumption for heating of only half of the maximum permissible according to requirements of new Greenlandic Building Regulations. Thus, the target heating consumption was set to 80 kWh/(m2∙year). The low energy feature was accomplished by using well insulated structures without cold bridges, a ventilation system with heat recovery, advanced windows and a solar heating system. In addition, it was an ambition that the indoor climate should be comfortable and healthy, and the highly insulated structures should remain free from moisture problems. Since its invention the building has functioned, in one half, as residence of a Greenlandic family, and as an exhibition in the other half. The building has been instrumented with sensors and a data logging system that measure the energy performance of the various parts of the system, and sensors for detection of moisture conditions in the building envelope and in the indoor environment. The energy performance data can be followed on the Internet on a day to day basis. The paper will present the house and the experiences from the first two years of its operation. An account will be given of the measured energy performance data. Some of the equipment did not function completely as anticipated, but some corrective measures are described, and the most significant challenges are discussed.