The aim of the work is to determine the possibilities of designing passive buildings in Latvian climate, with ensuring comfortable indoor conditions and convenient planning of the rooms in a building. For determine technical characteristics for building, a computer program TRNSYS has been used to build computer model which made it possible to obtain the thermally-technical parameters necessary for designing private houses in Latvia that would meet the passive building criteria. Two different forms of buildings were analyzed to find the best solution. Using the passive building conception, we can achieve a considerable reduction in its energy consumption. Compared with a new building of the same size and planning erected in compliance with the LBN 002-01 standard it is possible to save up to 85% of energy for heating.