The paper presents methods how the solar energy can be used for improvement of energy efficiency of large public buildings without using technical equipment such as solar collectors, solar panels and etc. The paper is devoted to the analysis of possibility for construction of double skin facades with changeable thermal performance for minimization of energy consumption by air conditioning systems. It describes the possibilities for optimization of thermal characteristics of double skin facades in order to improve buildings energy performance by maximal use of solar radiation including also the hot summer days with intensive solar radiation when usually shading devices prevent solar radiation. The paper gives mathematical model for regulation of elements of double skin facades depending on outdoor air parameters and level of solar radiation. It proposes constructive suggestion to create buildings whose walls, roofs and glassed surfaces have changeable thermal characteristics and methodology of control for separate elements.