Mycelium insulation and orientation strategies for reducing building energy demand in Southeast Asia

This study examines the combined influence of building orientation and mycelium-based composite insulation on cooling energy demand in Southeast Asian office buildings. Using the DOE Small Office prototype and Energy Plus simulations, three insulation thicknesses (0.18, 0.25, and 0.32 m) were tested across four cities (Bangkok, Hanoi, Singapore, Yangon) and eight orientations. Results indicate that increasing insulation thickness consistently reduces annual cooling loads, with 0.32 m achieving the greatest savings across all climates. Orientation also played a critical role: north-, northwest-, and south-facing buildings recorded the lowest cooling demand, whereas east-facing orientations performed worst. Cooling loads were strongly correlated with cooling degree days (CDD), confirming CDD as a reliable climatic predictor. Importantly, MBC insulation delivered thermal performance comparable to conventional materials while offering environmental advantages such as biodegradability and low embodied energy. These findings highlight that bio-based insulation with orientation-sensitive design can boost energy efficiency and cut carbon in tropical cities.