Construction of energy-efficient buildings becomes a top priority for many countries. Yet certain obstacles in achieving internal environment comfort standards remain in regions with extreme continental climate. In addition to engineering and economic challenges, there exist design process issues since design data should closely correspond with resulting performance of the building. The article deals with the concept of design of thermal envelope of buildings with low energy consumption for heating in winter and air conditioning in summer. Most influential factors are taken into consideration and general recommendations on improving energy efficiency using effective combination of structural solutions are given.