Air leakage path affect infiltration and air pressure conditions in building. The main objectives of this study were to analyse the distribution of the air leakage places and thermal bridges in detached houses and apartment buildings. Field measurements have been carried out in 30 detached houses and 21 apartments during the years 2005-2007. To determine typical air leakages and thermal bridges and their distribution, an infrared image camera and a smoke detector were used during winter period. Temperature factor was used to determine and to classify thermal bridges. Relative decrease of the surface temperature was used to determine and to classify air leakage places. Typical thermal bridges in the studied detached houses were around the doors and windows. Low temperatures were determined also in the junction of the base floor with the external wall. Typical air leakages were in the junction of roof with the external wall, penetrations through the air barrier systems, and around and through windows and doors. Typical thermal bridges in the studied apartments were around the doors and windows. Typical air leakages were around and through windows and doors, in the junction of ceiling/floor with the external wall, penetrations through the air barrier systems, and walls and floors between apartments.