Can We Really Cool Our Buildings?

Every summer, the question comes back like the heat itself: can we really cool our buildings without depending on machines?

In 2023, a client from Srirangam, Trichy, approached us with this kind of question. She lives in a 50-year-old house built in the 1960s, a beautiful, sturdy structure. Back then, there were no buildings on either side and the building naturally stayed cool.

She now lives abroad and visits Trichy occasionally, especially during summers. During her visit last summer, she found the living room unbearably hot. Four-storey buildings now flank both sides of her house, and even with all the greenery in the south-facing front yard, the heat had become trapped. She wanted to improve the thermal comfort of the home, especially the living room, but with minimal intervention, since it is an old structure. She also wanted to avoid depending heavily on air-conditioning.

Being a research scholar herself, she was curious about understanding the issue scientifically. We suggested an energy audit, which revealed the house’s temperature pattern, surface heat gain, and how air actually moved through the living room.

From there, our goals were clear:

• Reduce thermal gain from the walls and roof.

• Improve air circulation within the living room.

• Vent out the hot air that naturally rises in space.

She had already installed an exhaust fan to improve air circulation, complementing the limited cross-ventilation possible in the enclosed setup. As she rightly said, “Not building anything new is the most sustainable thing.” That stayed with us.

We began with simple moves, such as aligning the furniture layout with the direction of cross ventilation. Creating wall openings near the ceiling level (like traditional homes) could have helped, but since it’s a load-bearing structure, we decided to keep that as a last option.

We repurposed the skylight opening into a passive solar chimney, a vertical vent that uses heat from sunlight to draw out warm indoor air. We built a prototype-like structure to understand how the system performs. The openings were positioned based on the wind direction and sun path, and basic pipes and lids were used to operate it.

We also suggested reflective exterior paint to reduce heat absorption, dense plantation along the sides (with a drip irrigation setup) to block harsh sunlight, and a green roof to insulate against heat.

To supplement these, we explored evaporative cooling techniques and additional exhaust fans to keep air moving.

When she returned home this year, she said the difference was noticeable and the space felt much more tolerable, even during peak summer afternoons.

This project is still in progress, evolving phase by phase. Each summer brings new observations, what’s working, what needs refining.

Cooling our existing buildings is not about one-time fixes. It’s a slow, ongoing dialogue between design, climate, and care. Considering these factors at the design stage of new buildings could help us avoid such late-stage interventions. Sometimes, that’s where the most meaningful architecture begins.

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