The task of this final work was to design a heating and cooling system for a residential building. The project was made for a building located in Opatija, it is a family house with a ground floor and two floors, built in 2008. The main goal to design a heating system was to determine the heat losses of all rooms of the building that require heating. The calculation of heat losses was performed according to the standard HRN EN 12831. The obtained total result of heat losses suggested which wood pellet boiler together with all the accompanying equipment should be selected and also the tank of the system for preparation of domestic hot water. The heating system of the building is made with the already mentioned boiler and DHW tank and storage tank which are connected to the radiator circuit of central heating. The heat output and number of radiators in individual rooms is determined by heat losses in them. When determining the cooling system, it was concluded that it is needed only in the attic of the building for the greatest exposure of that part to external influences. For the purposes of determining the cooling system, the calculation of heat gains is performed according to the VDI 2078 standard. Based on this calculation and also the area of the room to be heated, the cooling system is determined. In the project, an air conditioner with an outdoor unit was chosen for cooling. The project also elaborates the pipelines themselves, ie the sizing of the entire pipeline for the heating system together with all the necessary equipment.