Kerala clay architecture cooling has moved from ancestral practice to lived reality for two sisters in Kannur, after Elemental Architects built them a family home that regulates its own temperature without a single air-conditioning unit.
Renu Krishnadas and Rekha Utham had returned to their 1.5 acres of family land set amid rice paddies, about an hour outside Kannur, after long careers elsewhere. They wanted a house on the land they had grown up around. What they did not expect was to be talked out of air conditioning entirely.
‘I was the first person to say that summers in Kerala are very hot,’ Krishnadas recalled. ‘I stayed for 21 days, and I never once switched on an AC. I did not feel the need for an AC at all. Even today, fans are good enough.’
How Kerala Clay Architecture Cooling Actually Works
The design, led by Elemental’s Amrutha Kishor, starts with the basics of airflow. Natural breezes arrive from the north, so the house was oriented along a north-south axis to let them travel through the full length of the living areas. Low open brick walls and clay lattices, known as jali, line the northern face, drawing air inside. Once inside, that air warms from sunlight or human activity, rises, and is channelled out through a series of high, angled windows positioned above the typical eye line. Those windows admit light without the direct solar heat that a standard window at sitting or standing height would bring in.
The jali openings and the gaps between bricks do more than simply let air pass. Because air and water accelerate when forced from a wide space into a narrow one, these features act as small pumps, speeding the airflow and dropping its temperature in the process. The same physics explains why air blown sharply to extinguish a candle feels cool, while ordinary breathing does not. Internal dividing walls are built from perforated clay blocks, which allow both air and moisture to move through them rather than building up on one side.
The skeleton of the structure is laterite, a local mineral. ‘Exposed laterite was common back in the day, but now it’s not very common in buildings,’ Kishor told The Better India. ‘We’ve tried to maintain that.’ Laterite absorbs and releases heat more slowly than many conventional building materials, and it can also take up moisture, a meaningful property in a state where humidity can often hang around 80%.
The Roof Layer That Slows the Sun’s Heat
The roof is where the Kerala clay architecture cooling strategy becomes especially layered, both literally and technically. Two courses of local clay tiles sit with a gap between them, slowing heat transmission from direct sunlight before it reaches the living space below. According to Architect and Interiors India, an air cavity formed between the Mangalore tiles and the concrete ceiling creates an additional layer of insulation against the scorching sun, compounding the effect of the tiles themselves. The result is a roof that works in stages rather than allowing heat to pour straight through.
The two sisters were sceptical when Elemental first proposed the no-AC design, and their caution was understandable. Kerala summers are genuinely harsh, with high humidity compounding the heat in ways that most passive cooling approaches elsewhere have not had to contend with. The fact that Krishnadas completed three weeks there without once reaching for the air-conditioning switch is a more honest test than a controlled experiment might provide.
Elemental has now applied these principles across dozens of structures. The materials, laterite, clay tiles, and jali, are all locally sourced, with roots in the region’s building tradition. What Kishor’s practice has done is systematise that tradition: working out the orientation, the ceiling heights, the wall perforations, and the roof layering as a coherent set of decisions rather than a collection of inherited habits.
The house stands as proof that the approach works at residential scale in one of India’s most demanding climates. Elemental’s next step, as Kishor has indicated, is to push these methods further into mainstream construction, a long road, but one that starts with a family of two sisters and no air-conditioning bill.
