In order to meet the requirements of the Energy Strategy 2050, there is the need for a large- scale energy retrofit of the current building stock combined with the use of solar active systems, in particular BIPV. However, existing tools to assess the potential solar energy yield, such as solar cadasters, present some limits. For instance, they usually consider only rooftops and do not include inter-reflections, neglecting or underestimating the potential for façade-applied systems. To overcome some of these limits, we present here a simulation- based workflow for the assessment of the BIPV potential in urban areas. Advanced solar radiation and PV-modeling tools are applied to detailed 3D city models, derived from 3D geodata that are (or will be soon) available for all of Switzerland. In the workflow, all building surfaces are first regularly subdivided according to a given PV module size. For each sub-surface, the POA irradiance is then calculated using weather data from Meteonorm and the software CitySim. We finally apply the Sandia cell temperature model and the De Soto “Five Parameter” model to calculate the DC power of the system.