In the master thesis, I analysed the impact of solar radiation on the energy potential of residential buildings and on the quality of daylight illuminance in interior spaces. In the first part of the thesis six different buildings that have a similar floor and balcony area were analysed and compared. The influence of geometric design and orientation of buildings on the insolation and energy potential of the building envelope in Ljubljana was studied. The Slovenian legislation requirements in regard to the insolation of the building envelope were examined. The results of the thesis showed that only two buildings met the requirements of the Slovenian legislation as for the insolation of the building envelope. Both of these two buildings do not have any balconies. The rest of the buildings have an interacting, similar insolation of the
building envelope, however they do not meet the insolation requirements of the Slovenian legislation. The energy potential of building envelopes on an annual period and during the heating season in Ljubljana was calculated. The energy potential of different, interacting building envelopes other was also compared. I have found out that the more diverse building envelope has the lowest relative energy potential. Some differences in the energy potential of building envelopes amongst the more conventionally designed buildings were noted. In the second part of the thesis the illuminance of two apartments in the more diverse building was analysed. Based on the insolation results I assumed the chosen apartments are the best and worst daylit apartments in the building. The illumination levels on a horizontal working plane of 0.85 m was analysed and later the illumination results of the two apartments with the predefined illumination requirements were compared. The results showed that the orientation and location of the apartments in a building have a major impact on the illuminance levels.