In this thesis, the main task was designing the heating and cooling system of a residential building according to the architectural proposal using different energy sources. The building is located on the territory of continental Croatia and consists of two apartments. The heating and cooling system of residential building was desinged according to calculated heat losses and heat gains using guidelines and valid norms with the aim of finding optimal solutions and achieving the designed internal temperature. Calculation of heat and cooling loads as well as heat transfer coefficients were performed using the Integra Cad program according to HRN EN 12831 and VID 2087 standards so appropiate energy sources and heating elements were selected acoordingly. For the first apartment, an air-water heat pump was selected as a source of heat for cooling and heating with a fan convector with a maximum hot water temperature of 60°C and cold water 7°C. Temperature regulation is done using regulation of the upper crane and by means of touch displays located on the fan coil units. For the second apartment, as heat source was chosen condensing device powered by natural gas, which heats apartment using ventilated plate radiators, while classic multi split air conditioners were chosen for cooling, At the end, was made an analysis of the annual energy cost for apartmant 1 and apartment 2 and there are given the plans of ground and first floor, as well as functional connection shemes in the attachments.