This paper analyzes the indoor hygrothermal loads measured in 27 detached houses and in 13apartments. A survey was conducted during the years 2003-2006 in Estonia. The temperature andrelative humidity (RH) were continuously measured in bedrooms, living rooms, and outdoors at onehour intervals. For the hygrothermal analysis, the determined design curve of the moisture excess forhouses with low occupancy on the higher 10 % critical level was +4 g/m3 during the cold period(Tout ? +5 C) and +1.5 g/m3 during the warm period (Tout ? +15 C). The determined moisture excessfor apartments was +6 g/m3 during the cold period. The daily average moisture production in studieddetached houses during the winter season was 5.4 kg/day/house (1.6 kg/day/person) on the average.