The paper presents the results and analysis of the calculation of the reduced total thermal resistance of the external building envelope (walls) for general education schools. The school, which the heater was picked up, is the student's project. This object is designed for 550 pupils, the school has three floors. Article is devoted to the solution of an actual problem — to energy saving and increase of energy efficiency of buildings. Also in the article there is a definition of optimal and profitable width of insulation in a system of hinged ventilated facade. The technical calculations are presented and optimal width of heat-insulating layer is given in this project. The company ISOVER offers ISOVER VENTI heat insulation for walls, which have a line of advantages: the ability to use both single-layer and double-layer insulation system (as the outer layer), is used in all types of buildings without height restrictions, the effective removal of the moisture from the structure due to the high vapor permeability, refers to a group of non-combustible materials, which is an important aspect for the educational institution.