Solar collection multi-isosurface method: Computational design advanced method for the prediction of direct solar access in urban environments

Direct solar access and daylight requirements contribute significantly when it comes to shaping the layout and appearance of contemporary cities. Urban planning regulations in Estonia set the minimum amount of direct solar access that existing housing has the right to receive and new premises are required to get when new developments are built. The solar envelope and solar collection methods are used to define the volume and shape of new buildings that allow the due solar rights to the surrounding buildings, in the case of the former, and the portion of the own façades that receive the required direct solar access, in the case of the latter. These methods have been developed over a period of several decades, and present-day CAAD and environmental analysis software permits the generation of solar envelopes and solar collection isosurfaces, although they suffer from limitations. This paper describes an advanced method for generating solar collection isosurfaces and presents evidence that it is significantly more efficient than the existing method for regulation in Estonia’s urban environments.