For the purposes of the thesis, the possibilities of simulating the thermal model of a new family house located in the vicinity of the city of Rijeka with a usable area of 273.24 m2 were analyzed. The analysis of the influence of thermal accumulation was examined through three levels of detail, depending on the number of thermal zones of the simulation model, and two building, classical and prefabricated construction methods. A 3D model was used to perform thermal model simulations and determine the required thermal energy for heating and cooling the house, which needs to be thermally adjusted according to the given operating parameters, boundary conditions, etc., with a time step of 60 minutes for the reference year. The thermal zones of the building define ideal heating and cooling with unlimited effect with a designed temperature in the rooms of 20 °C for heating and a temperature of 24 °C for cooling with a relative humidity of 50%. Depending on the time step of the thermal model simulations, the obtained data were analyzed with a time step of 30 min, 10 min and 5 min. Internal gains of 5 W/m2 per surface of the thermal zone, and natural ventilation of 0.64 h-1 was applied for all thermal zones. The impact on heat accumulation was observed due to the interruption of heating in the winter in the night period from 10 pm to 6 am. In the same way, the impact on the heat accumulation was examined with regard to the interruption of cooling with the interruption of operation from 10 pm to 6 am, with the condition that the ambient temperature is lower than the air temperature of the thermal zone. The use of natural ventilation in the summer at night was also tested. For all versions, a heating season is defined that lasts from the first to the end of the fourth month in the first part of the year and from the tenth to the end of the twelfth month, and the cooling period is from the fifth to the end of the ninth month. The family house has active internal shading on all windows and external shading on the windows located on the southern facade of the house.