This study aims to quantify how future climate change will alter thermal comfort and cooling demand in newly built single-family and multi-family detached houses in Chennai and to identify the most climate-resilient envelope wall materials and passive retrofit measures.
A three-step performance assessment was applied: (1) baseline simulation of the two case buildings under four Intergovernmental Panel on Climate Change (IPCC) AR6 Shared Socio-Economic Pathways (SSP1–5) for 2050 and 2080; (2) evaluation of 60 opaque wall materials on indoor operative temperature (TOP), adaptive discomfort days (DD) and annual cooling load (CL) and (3) assessment of six passive retrofit measures. Simulations were performed in EnergyPlus via a Rhino-Grasshopper workflow with a calibrated energy model from empirical data validation. Climate data for future scenarios were generated with the Future Weather Generator (v3.0.0).
Under SSP5 2080, adaptive discomfort days increased 3.5–4.5 times, and in SSP1 2080, the mean operative temperature increased 1.5–1.8°C, relative to the Typical Meteorological Year. The Autoclaved Aerated Concrete (AAC) block (AB01) consistently delivered the lowest cooling load across all scenarios. Cool wall paint reduced the adaptive discomfort days by 14.6–15.7% in the SSP5-2080 scenario.
This study emphasizes the importance of climate-resilient building designs and provides actionable insights for selecting the optimum locally available envelope material and low-cost retrofit measures to improve climate resilience.
This study combines future climate projections with building performance, detailed envelope material screening for compliance and climate resilience and practical low-cost retrofit options, emphasizing the importance of performance-based design decisions for maintaining comfort under projected heat extremes.
