One of the most promising sustainable energy that can be considered in urban environment is solar energy. A 3D model for solar energy potential on building envelope based on urban LiDAR data was developed in this study. The developed algorithm can be used to model solar irradiation with high spatio-temporal resolution for roofs, facades, and ground surfaces simultaneously based on urban LiDAR data taking into account the vegetation. Global solar irradiation was then obtained for each point on the buildings and ground surfaces with a spatial resolution of 1m2 and a time resolution of 1 hour. The algorithm has been implemented in Matlab and the results were generated for two different test areas in the city of Geneva in Switzerland. The results show that even in a dense urban area, the upper parts of south-east to south-west oriented facades receive 600 to 1000 kWh/m2/year of solar input which is suitable for active solar installations. The results also show that south oriented facades can get higher solar input during winter months than the low inclined roof surfaces. This shows facades have a significant impact on the solar potential of buildings in an urban area, particularly for a sustainable energy planning application.