This study presents an efficient model for the calculation of 3-dimensional time-resolved solar potentials, based on the Perez solar model. The new model features a novel interpolation scheme for the generation of annual hourly time-series, diffuse and specular inter-reflection, a multi-layer approach to model the attenuation of solar radiation through vegetation, and snow-coverage. It is fully integrated in a 3D CAD environment to facilitate its application. Extensive validation case studies prove the high match of the new model to three other well-established programs: Radiance, Daysim and EnergyPlus. A thorough analysis of the effect of various model parameter settings highlights the importance of assessing site specific characteristics and modelling uncertainty caused by parameter selection. Our results show a significant reduction in computing times compared to Daysim and EnergyPlus, while generating less mismatches in geometric obstruction calculations when assuming Radiance as a reference. Furthermore, the considered case studies suggest that modelling the shading effect of vegetation is indispensable in solar potential analyses and should not be neglected.