Author: Sunit Tandon | Neha G
When summers make homes unbearably hot and winters bitterly cold, comfort often comes at a cost: rising electricity bills from air-conditioners and heaters. As India faces frequent weather extremes, the contribution to high costs and subsequent carbon emissions undermines a sustainable future. For centuries, India’s diverse regions developed climate-responsive building practices that worked with local conditions to support human comfort. Historical treatises such as the Samarangana Sutradhara and Mayamatam discuss spatial organisation, materials, courtyards and gardens in relation to the environment. As climate change reshapes building needs, revisiting this traditional architectural heritage could offer valuable lessons for comfortable, energy-efficient buildings today.
In the cold Western Himalayan regions, Srinagar’s dhajji diwari houses exemplify centuries-old climate-responsive architecture. Built with natural thermal insulators such as moisture-resistant deodar wood and mud plaster, along with heat-absorbing stone/brick infill, they trap heat indoors and keep the cold out. In Himachal Pradesh, the indigenous kath kuni houses use double-skinned walls made of alternating wooden beams and loose stone infill (that contains trapped air), creating an effective insulating layer. Interior mud plaster further reduces heat loss, keeping homes naturally warmer. In the wetter Eastern Himalayas, the Mon people of Chug Valley, Arunachal Pradesh, build traditional wahm houses from local rocks, clay and wood. Their thick stone-and-clay walls help keep interiors cool in summer while shielding occupants from frigid rains and winds during the monsoon and winter.
Across the hot and arid or semi-arid landscapes of states such as Rajasthan and Gujarat, baoris or stepwells, such as the Chand Baori, Rani ki Vav, Adalaj ki Vav, formed part of the traditional systems of water management and community life. Apart from providing groundwater and aiding in water conservation, their descending stairways, subterranean chambers and stone-lined shafts provided shade from the sun’s heat and cooled surroundings. For instance, the Adalaj Ki Vav is a five-storeyed octagonal stepwell, whose ceiling openings let air and light into the well. Direct sunlight never touches the steps except at noon, maintaining cooler temperatures inside the well.
Traditional homes, such as Rajasthan’s havelis and Gujarat’s pol houses, have courtyards that serve as social hubs and natural microclimate regulators. During the day, shaded courtyards remain cooler than the hot outdoor air. As the warm air inside rises and escapes (the stack effect), cooler, fresh air is drawn in from surrounding rooms and verandahs. At night, open-sky exposure releases the stored thermal heat while cool air sinks into the space, cooling the thick masonry walls. Many courtyards also feature central plants or water features that cause further cooling through evaporation. Several such homes also harvest rainwater within their premises. The collected rainwater in the courtyards gets drained into the basement, beneath the central courtyard, further cooling the atmosphere.
India’s architectural heritage further boasts of a perforated screen made of stone, the jali. Jalis offer benefits, such as passive cooling and glare mitigation, over glass. Once air enters through the screen, the small chambers cause it to increase in velocity and drop in pressure, which in turn cools the air and ambient temperature (the Venturi effect). For instance, the eastern façade of Hawa Mahal in Jaipur, Rajasthan, features 953 intricately carved jharokhas equipped with stone-pierced jali screens. These jharokha windows aid in making the interior spaces pleasant during the high summer temperatures.
Materials such as Makrana marble, red/pink sandstone and red bricks were commonly used to build notable structures such as the Taj Mahal, Agra Fort and Hawa Mahal. These dense materials have high thermal mass; they absorb and store large amounts of heat during the day and release it gradually as night temperatures drop. In contrast, today’s thin, uninsulated concrete walls transfer high temperatures directly into building interiors within hours, while concretised urban surroundings retain heat and amplify the Urban Heat Island (UHI) effect long after sunset. Furthermore, surface albedo plays a critical role in passive cooling: exterior surfaces made of marble or finished in light colours reflect solar radiation, avoiding dark colours that absorb more heat. For example, the traditional buildings of Jaisalmer, Rajasthan, use light golden-yellow sandstone to reflect intense solar radiation. Interior mirror work, as seen in the Amber Fort, Jaipur, Junagarh Fort, Bikaner and Bhungas, Kutch (Lippan kaam), naturally amplifies indoor lighting through multiple reflections, while exterior mirror work on the Bhungas and other rural homes complements the light-coloured lime-plastered walls, reflecting away harsh heat.
Adequate tree cover and green landscapes can reduce temperatures significantly through shade and evapotranspiration. For instance, the Isa Khan Tomb, Delhi and Amber Fort, Jaipur, display the calming effect of greenery, often further enhanced by cooling water features. Indian subcontinent’s prominent garden-tomb, Humayun’s Tomb, Delhi, is centred within a four-quadrant charbagh landscape. Fruit orchards, flowering trees and other natural vegetation provided shade and food, complemented by cooling fountains and water channels.
In warm, humid tropical climates, vernacular architectures such as the Chang Ghar, Assam and Nalukettu, Kerala, developed natural ventilation and protection from heavy rains over centuries. Along the flood-prone Brahmaputra plains, the indigenous Mising tribe from Assam builds the Chang Ghar, a stilted house raised above ground level. The stilt height is determined by the highest local flood levels. Families live on the upper floor (which gives access to cool air), while the ground floor accommodates poultry and livestock. The construction materials used are lightweight, flexible and readily available. Perforated bamboo walls and floors allow air circulation, keeping the interiors cooler, while thatched or reed roofs provide cover.
Nalukettu (meaning ‘four blocks’) is the traditional homestead system prominently found in the coastal regions of Kerala. Four halls are arranged around a central open courtyard (nadumuttam), which brings light and ventilation into the house. Laterite stone walls, plastered with a mix of mud, straw and organic binders, e.g. cow dung, provide thermal mass to moderate indoor temperature fluctuations. Teak and jackfruit wood are used for beams, columns and other structural elements, while terracotta bricks and clay tiles are suited to the region’s warm, humid climate. The steep-sloping tiled roof, supported by wooden beams, allows heavy monsoon rain to drain quickly. Extended rafters and deep eaves protect the walls from sun and driving rain, while gabled roof windows help release hot air trapped beneath the roof. Here too, the central courtyard draws warm air out and pulls cool breezes in to relieve humidity.
India’s architectural heritage shows how vernacular knowledge can regulate microclimates without energy-intensive technology. Structures tailored to local climates, such as cold, hot-dry and tropical wet climates, consume less energy, ease infrastructure strain and perform better during extreme weather. Modern designs can adopt IKS-grounded passive strategies, such as leveraging courtyards and jalis for airflow, prioritising sustainable materials such as bamboo and terracotta, among others.
In line with Bharat Ki Soch’s vision of synthesising this vernacular wisdom with modern engineering for future sustainability, embracing these lessons allows us to construct modern spaces that provide a practical pathway towards low-carbon, climate-resilient cities.
Sunit Tandon, Former Director, India Habitat Centre; DG-IIMC; Hon. Visiting Fellow, Bharat Ki Soch; Neha G, JR. Research Fellow, Bharat Ki Soch; Views presented are personal.