This paper presents design solution of heating, ventilation and gas installation of elementary school in Bregana. The existing school building is built on and the new building consist of basement, ground floor and the first flood. The paper contains calculation of transmission and ventilation losses according to norm HRN EN 12 813, based on architectural plans. The solution of heating system is chosen to be central radiator heating system. Heat source are two boilers with complementary gas burners, all placed in boiler room in basement. The boiler room also contains circulation pumps, pumps for individual heat circuits, collector, water softener, expansion module and DHW tank. Also, the paper discusses the ventilation of the school. The ventilation system is explained in detail as well as all of his components. The layout of the ventilation equipment on the floor is supported by the corresponding drawings. The ventilation chamber, which is set up for the needs of the restaurant and kitchen, is described in detail. Furthermore, the function of exhaust sanitary fans is explained in detail as well. The paper also presents the calculation of chimneys and describes the method of dimensioning them. The most important component of the entire technological system of the building in question, which connects the operation of all its components, is automatic regulation. The paper explains the importance of automatic regulation and describes its components in detail. Also, all the advantages of automatic regulation are described and it is explained why it is difficult to imagine having a functional technological system without it nowadays.