Beyond Patterning: Embedding Shading in Opaque Building Envelopes

This research explores the passive solar self-shading of building opaque surfaces through small-scale patterning embedded in material units. The investigation focused on concrete masonry unit (CMU) blocks as they are moldable into various patterns and commonly used as uninsulated construction material for exterior walls. With CMU as the medium for the study, the authors developed surface patterning systems to externally shade the opaque wall surfaces that might require compound shading due to their solar exposure. The hypothesis is that self-shading buildings' exposed thermal mass by embedding shading patterns is an opportunity to shave cooling building loads and provide a performative purpose that goes beyond ornamental architectural patterning. However, current building energy simulation workflows have limitations in modeling small-scale shading, particularly those embedded within a material unit. To address this limitation, this work proposes and validates a novel co-simulation method that allows for the testing and refining of passive shading patterns. Using the proposed approach, it was possible to devise a feedback loop of material testing and simulation to assess and optimize the energy performance benefits of embedding shading patterns in an exposed CMU building surface. First, the research examined the potential of optimally shade exposed thermal mass in a south-facing building using an overhang in warm to hot climates. Then, the authors used the proposed co-simulation method to design and assess different CMU groove patterns' ability to reduce building cooling loads. The results show that optimally shade exposed thermal mass can reduce cooling loads by 29% in hot climates, while carving small-scale shading in CMU can reduce cooling loads by 15%.