The ‘Blue House’ is a standard family detached house built by Panbo Huse A/S in 1985 in Sisimiut, Greenland. As an old building, it has many problems such as poor thermal comfort and high energy consumption, and therefore, the house has a potential to be retrofitted. The investigation of the ‘Blue House’ was carried out in August 2011, including collection of original documentation, visual inspection, blower-door test, thermography test, the indoor climate monitoring, questionnaire and interview with the occupants. The indoor climate, including temperature and relative humidity, has been recorded since December 2010. The results of the investigation show that the house has some serious problems influencing proper functions, such as thermal bridges, poor thermal comfort and high energy consumption. A retrofitting plan, including having an additional paper insulation layer and exterior climate shield, has been proposed and will be carried out in 2012. Although the blower-door test shows that comparing with the considerably large number of houses built in past times in Greenland, the ‘Blue House’ has a relatively high air tightness, the thermal performance of the house needs to be improved. Due to the harsh climate in Greenland and the low building standard in the earlier period, it is still a major challenge for Greenlandic building industry to retrofit existing buildings.