The aim of this graduation thesis was to compare optimal concepts and working parameters of the heating, cooling, domestic hot water preparation and ventilation for a family house that would be built as a net zero energy building(nZEB) or as a passive house built according to the rules of the Institute for Passive Houses. After the calculation of heat losses and gains, an analysis of three possible thermotechnical solutions for building a house as an nZEB was carried out and it was found that the most optimal solution is the one that uses a heat pump in combination with radiator heating and air conditioning for cooling the rooms, with the addition of a photovoltaic system of 415W in order to meet the norm of permitted primary energy consumption. In addition, a comparison was made of that thermotechnical system with the one that would be installed in a passive house that was built according to stricter standards and the calculation showed that the most optimal solution is to build according to the stricter standards with underfloor heating during the winter and free cooling during the summer with natural ventilation. The possibility of installing photovoltaic panels of 2.9kW and 4.56kW was taken into consideration, but the investment costs and future maintenence costs were still too high to make their installation worthwhile at this time, so the most cost-effective option was the construction of a passive house without a photovoltaic system.