CAADRIA 2025

Published 26 March 2025

The Impact of Natural Ventilation on Building Form Optimisation for Energy Efficiency: A comparative study of surface-to-volume ratio with and without natural ventilation

Yang Yang, Lok Hang Cheung, Likai Wang

This study investigates the impact of natural ventilation (NV) on the optimisation of building form factors, particularly the surface-to-volume ratio (SVR), in reducing energy consumption. Traditional approaches minimise SVR to lower energy use by reducing heat transfer, often at the cost of design flexibility. However, incorporating NV can enhance energy performance without requiring restrictive SVR reductions in hot or warm climates. A comparative optimisation study was conducted using two scenarios-one with NV and one without-revealing that solutions with NV achieved lower energy use intensity (EUI), even with larger SVRs. Results indicate that NV not only reduces EUI but also allows for more diverse building forms, enabling designs with increased cantilevers and reduced repetitive massing without energy penalties. This research extends prior studies by examining the whole-building impact of NV rather than isolated design elements. Future studies may delve into how factors like wind speed and direction influence SVR and energy performance, offering actionable insights for architects aiming to balance energy efficiency and architectural flexibility.