Solar irradiance and illuminance are important renewable resources that can significantly increase buildings’ energy efficiency, associated to solar passive and active techniques and use of daylighting. In addition, it is widely acknowledged that the presence of natural light and some sunlight indoors is essential for inhabitants’ well-being. This paper presents a new method to assess solar and daylight availability in the built environment at different scales. The method is based on two types of images where the mutual obstruction between neighbouring buildings is represented over stereographic projections of the sky vault. The images can be used in two ways, either for the visual assessment of the examined surface(s) or, to be processed as to obtain a series of numeric performance indicators. In both ways, they can be combined with similar projections of the sun path or sky radiance/luminance distributions, for considering locations’ latitude and climate, respectively. To exemplify the use and relevance of the tools, especially at the early-design stages, the method is applied to compare the proposals submitted in a masterplan competition. The five finalists are examined in relation to the performance of their fac¸ades and roofs, as well as their impact on an existing fac¸ade. Last, a targeted analysis showed a good correlation between performance indicators, readily computed by the method, and predicted annual energy demands.