Study moots 'hot' step to climate-proof buildings

Researchers at CST, IISc, have tried to plug the gaps by testing projected climate change scenarios on 310 locations across climate zones

Climate classifications remain critical in the planning and designing of buildings but recent research has also identified gaps in these broad groupings, most of them attributed to the exclusion of climate change patterns.

Researchers at the Centre for Sustainable Technologies (CST), Indian Institute of Science, have tried to plug the gaps by testing projected climate change scenarios on 310 locations across climate zones. Underlining a warming trend observed in the locations, they contended that existing classifications need to be revised to ensure climate-efficient building designs.

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The findings of the study by Aysha Saifudeen, Roshan R Rao and Monto Mani were published in social sciences journal World Development Sustainability. “The research is built around concepts of architecture and design. Follow-up studies by climate scientists could add context to these findings and address questions about buildings under climate change,” Aysha told DH.

The cities representing the five climate zones in the study were Jodhpur (hot-dry), Chennai (warm-humid), Bengaluru (temperate), Guwahati (cold) and Delhi (composite zone, without a definite pattern for more than six months).

The researchers proposed a revision by adding a zone — extreme-hot — to the existing five categorised by the National Building Code (NBC).

The NBC, which features the most accepted climate-specific standards, bases its classification on mean monthly maximum temperature and mean monthly relative humidity.

For zoning, it considers the duration for which the regions are exposed to the conditions — a region with a weather pattern consistent for six months, for instance, is classified under one zone.

The researchers noted that most of the existing classifications do not factor in hourly temperature data — crucial in tracking daytime temperature changes and their impact on indoor comfort — or anticipate variations in future climate.

The study said while these classifications, including the NBC’s, drew on earlier studies, the more recent research has explored reclassification of climate zones but without factoring in climate change.

Scenarios, projections

Working with weather data generator Meteonorm, the researchers collated weather station data and interpolated data generated by computational models. They applied on the 310 locations three emissions-based future scenarios developed by the Intergovernmental Panel on Climate Change: A1B (balance between fossil and non-fossil fuel sources), A2 (increasing global population, regional economic growth, fragmented and slow technological change) and B1 (rapid economic changes, clean and efficient technologies).

Seven temperature ranges — from 10°C-15°C to 40°C and above — were picked and patterns of warming identified, based on temperature variations across the three scenarios, between the years 2020 and 2100, Aysha said.

The CST study confirmed a warming trend in all the zones, with hot-dry, warm-humid and composite zones projected to have “a considerable increase” in the number of days that have the daily maximum temperature at 40°C and above.