Geo-solar segmentation mechanism: An early design stage method for building solar morphing

Abstract

Building envelope shape plays a crucial role in determining the building energy performance, by regulating its solar exposure and the incident solar radiation. However, there are limited solar morphing tools that allow the generation of static building envelope. Besides solar potential, building shape performance indicators need to be considered, such as space efficiency and shape coefficient. Therefore, the present study proposes the ‘geo-solar segmentation’ morphing method that can help architects and engineers generate a range of optimal building shapes based on received solar radiation, shape coefficient and space efficiency in the early design stage, under different climate conditions. Accordingly, based on the top–down biomimetic approach, the solar-induced rock cracking mechanism is adopted as a source of inspiration to generate an architectural design concept. It is then, transcribed into a solar design generation and optimisation algorithms using visual programming in Grasshopperְ within the Rhinoceros software. Octopus, an evolutionary solver is used to perform the multi-objective genetic algorithm optimisation. A comparative study is conducted between optimal solar segmented building envelopes and a reference rectangular-based shape. The results demonstrate that under hot climate, optimally segmented building envelopes are 44.90% more effective in terms of solar protection than rectangular-based ones, and allow a trade-off between solar protection and collection under temperate climates. Moreover, the method helps reduce the shape coefficient by at least 10.30% for any climatic location, while ensuring a minimum space efficiency of 95%. The suggested method can be used as an early design-stage tool to enhance static envelope energy performance.