In the thesis we analyzed an existing passive house building regarding the parameters of energy use and indoor environmental quality indicators. The method includes a combination of in-situ measurements of energy / indoor environmental quality indicators and calculation methods. We carried out the thermal imaging of building envelope in order to check the thermal bridges. Calculated heat flux / U values of constructional complexes were compared with the measured ones and we have found out that there are differences between them. We created a calculated energy certificate of the building and obtained other data on energy use. Indoor environmental quality indicators (selected parameters of the thermal environment, the lighting environment, the interior air quality) were compared with the mandatory and recommended values. Measurements of indoor CO2 concentration during the increased activity time have shown the exceeded values regarding the recommendation by ANSI / ASHRAE Standard 62.1-2004. We proposed natural ventilation, and in case of recuperator use more intensive operation level must be set up. The ventilation system must be regularly cleaned and maintained. The indoor air temperature, the surfaces temperature of building envelope, the mean radiant temperature and the operative temperature were in accordance with the recommendations of the Rules on ventilation and air conditioning of buildings during the measurement period. Radiative asymmetry was minimal. Relative indoor air humidity was very low at the time of winter measurements. Therefore, when the frequent use of the fireplace, humidification is required. Too high relative humidity values were shown during the summer and we have no possibility to control it because they are the result of outdoor climate conditions. Measured values of daylight illumination did not reach the recommended limits in only one part of the observed area and thus we suggest additional lighting. The noise level due to occasional outdoor factors has exceeded the limit according to the Regulation on sound protection of buildings. Given the good energy efficiency, we proposed to increase the use of renewable energy sources. We have come to the conclusion that in order to balance the indoor environmental quality with energy efficiency, the building design and engineering must follow the needs, heath and comfort of users.