Solar Form Finding: Subtractive solar envelope and integrated solar collection computational method for high-rise buildings in urban environments

Daylight standards contribute significantly to the form of buildings and the urban environment. Direct solar access of existing and new buildings can be considered through the use of solar envelope and solar collection isosurface methods. The first determines the maximum volume and shape that new buildings cannot exceed to guarantee the required solar rights on existing surrounding facades. The latter predicts the portion of facades of new buildings that will receive the required direct sunlight hours in urban environments. Nowadays, environmental design software based on the existing methods permits the generation of solar envelopes and solar collection isosurfaces to use in the schematic design phase. Nevertheless, the existing methods and software present significant limitations when used to design buildings that must fulfil the Estonian daylight standard. Recent research has successfully developed computational workflows based on the existing methods and available tools to tackle such shortcomings. The present work uses the findings to propose a novel computational method to generate solar envelopes and integrate solar collection analysis. It is a subtractive form-finding method that is more efficient than the existing additive methods and other recent workflows when it is applied to high-rise buildings in fragmented urban environments. The tests performed show that the new method permits the realisation of compliant and larger solar envelopes, which furthermore embed formal properties. The objective of the research is to contribute to the development of computational methods and tools to integrate direct solar access performance efficiently into the design process.