Did this summer feel hotter than usual to you? You aren’t alone. With an uptick in heatwaves and pollution, we seem to be teetering on the brink of a very uncertain and bleak climactic future. Traditional techniques such as courtyards, jaali screens, and wind towers, among others—often reinterpreted in a contemporary language—form the basis of passive home cooling techniques that are becoming increasingly important in a world where artificial cooling is only accelerating our climatic woes. Turning back to draw inspiration from such tried-and-tested, locally resonant, vernacular concepts for cooling seems imminent. With the advice of Indian architects putting these sustainable theories to practice, AD rounds up 5 timeless home cooling techniques, some of which you can even apply in your apartments today.
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Harnessing Evaporative Cooling
The use of water bodies to bring down surrounding temperatures—a concept grounded in evaporative cooling—was championed by regions in Rajasthan and Gujarat, through stepwells (locally known as baolis), which served as both sacred gathering places and powerful passive cooling engines. Plunging many metres below the heated ground, from where hot air descends, these stepped caverns tap into the water table to create cool, humid breezes that refresh adjacent rooms and courtyards.
This concept of employing evaporative cooling has since found contemporary reinterpretation beyond stepwells. Meetu Akali, principal at Goa-based Studio Momo, underscores her penchant for introducing water bodies in her designs. “I love courtyards as they create a microclimate, and by strategically introducing a water body such as a fountain or a lotus pond, the temperature of the breeze flowing through it can be brought down by a few degrees,” she explains, along with using techniques such as curating the position of the water body under existing tree shade to ensure lower temperatures.
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Pro-tip for apartments: “During the afternoon, block our direct sun-light using a shade or blinds. Khus or vetiver curtains when sprinkled with water creates evaporative cooling in hot and dry areas, these can be used on windows and large openings to not only reduce the temperature and diffuse light but also to create an earthy aroma,” says Akali.
The Jaalis of Yore
“Painstakingly carved jaalis from red and yellow sandstone have been a part of India’s architectural vocabulary since the 16th century, owing to exquisite palaces, forts and mosques native to Mughal and Rajasthani architecture,” Sandeep Khosla, founder and principal of Bengaluru-based Khosla+Anand explains. This principle was translated into affordable, modular masonry by many late 20th-century practitioners such as Laurie Baker, offsetting bricks to leave regular voids. These screens filter harsh sunlight (while aesthetically enhancing the space with shifting patterns of diffused light) and the thermal mass of bricks absorbs daytime heat, releasing it only when outdoor temperatures fall.
Khosla identifies as a contextualist who believes that architecture should be rooted in its environment, guided by the question: ‘what building does this site really want to see?’ In cities with vertical density, Khosla reiterates the importance of filtering in light through such screens to create buildings that breathe, and warns against aping the west to create curtain wall glass buildings, which first trap heat and then require vast amounts of mechanical systems to cool the volumes inside.
Pro-tip for apartments: Jaali screens—which employ the venturi effect (where air passes through small apertures to gain velocity while dropping temperatures) for cooling—can be installed as exterior walls, filler panels or even interior partitions. Contemporary materials such as GRC (glass reinforced concrete) and MDF can be laser-cut to install jaalis in strategic locations as a design renovation.
The Terracotta Trick
Across the arid and semi-arid regions of India, thick terracotta block walls (often perforated to form breathing screens) are misted periodically, triggering water evaporation which absorbs a significant amount of heat from the surrounding. The microporosity of clay greatly enhances this effect, forming an effective cooling technique that uses no electricity and can lower wall temperatures upwards of 5 degrees celsius. The principle is most simply understood with the matka (an earthen pot) as an example: the water inside the matka stays chilled owing to some of it seeping through the porous clay and evaporating, resulting in heat being drawn outwards.
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Monish Siripurapu, founder of Cool Ant and Ant Studio (a sustainability think tank leading an innovation revolution by reviving terracotta and transforming it into passive cooling systems) explains: “Over the past decade, we’ve worked extensively with earthy, breathable materials like terracotta, mud, and brick—not simply for their aesthetic appeal, but for their thermal performance and sustainability. These materials are inherently porous, facilitating temperature regulation, natural air movement and evaporation, which directly contribute to cooling.” In his work, terracotta-based building envelopes, art installations and cooling towers inspired by historical techniques come together in different modules such as the Beehive, Binary and Terrabyte—natural cooling systems composed of modular terracotta cones, tiles and even debris.
Pro-Tip for apartments: Take inspiration from and experiment with CoolAnt’s concept of terracotta cooling towers called Beehive. It reverses and then harnesses the power of the matka. Handcrafted terracotta cones stacked and fitted into a stainless steel frame are moistened with recycled water and air is passed through them, allowing water to evaporate from inside.
The Courtyard Effect
For Veeram Shah—founder and principal of Design ni Dukaan—who grew up in Navsari, a quiet Parsi town on the west coast of India, the surrounding architecture quietly evolved with the climate, not against it. “Comfort was achieved not just through local materials, but through a thoughtful progression of spatial scales—courtyards, backyards, open terraces, and abundant greenery,” he remembers, and his work instinctively bears these marks, with courtyards being a recurring element. “In Enclosure, I designed a series of courtyards scaled to suit different functions. Intimate, smaller courtyards adjoining all private spaces, offering secluded pockets of calm, while larger courtyards and verandahs extended the public zones, framing greenery and encouraging interaction,” he reveals, carving out these extensions to the living spaces that naturally temper the environment while fostering a connection.
Under the Earth
The Earth’s stable, subterranean temperatures have long provided shelter for carving out tunnels, cellars, and semi-buried chambers. Tribal communities in Ladakh and Kashmir built partially into the hillsides as a response to scarce timber and extreme diurnal temperature swings. Even in tropical Kerala, homes featured sub-floor vaults for food storage and buried earth tubes excavated into shaded courts pre-cooled incoming breezes. Situating spaces partially or fully below ground level can help tap into the ground’s natural thermal inertia: while daytime temperatures soar outside, the earth maintains a constant temperature of 18-22 degrees celsius. The strategy maintains a soothing indoor climate year-round while also minimizing the structure’s visual impact, allowing it to blend seamlessly with the landscape.
Avinash Ankalge, principal and co-founder of A Threshold, utilises these principles in Karnataka’s Kaggalipura village, in a multifunctional social site christened Subterranean Ruins. “The idea of utilising thermal properties of natural materials and submerging masses to reduce heat gains and increase thermal comfort inside the building have always intrigued me,” reveals Ankalge. By leveraging the surrounding topography and embracing the existing contours on site, parts of the southern section sink up to 4 metres into the ground, allowing the spaces to remain cool. Beyond this, Ankalge’s work regularly features rammed earth constructions, timber vaults, terracotta bricks, and naturally available stones.
NOTE – This article was originally published in architecturaldigest and can be viewed here
