Words by Vaani Bhala
Field Notes from India
Glass is often treated as the default material of modern architecture. It promises transparency, light, and openness. Yet in climates where heat, dust, and glare dominate, glass is a relatively recent and often problematic solution. Long before glass façades became common, Indian architecture relied on jaalis. Perforated screens carved in stone, wood, or clay were used across palaces, homes, temples, and civic buildings. These screens did not merely decorate walls. They regulated light, filtered air, provided privacy, and shaped how spaces were inhabited. Jaalis were not ornamental additions. They were architectural intelligence embedded into structure.
"Before transparency was about seeing out, it was about letting air and light move in."
Jaalis appear across regions and periods in the Indian subcontinent. From Mughal architecture in North India to temple complexes in the south, their forms vary, but their purpose remains consistent. They act as mediators between inside and outside. The geometry of a jaali is not arbitrary. The size of perforations, thickness of material, and depth of carving determine how much light enters, how air circulates, and how heat is diffused. These decisions were shaped by climate, orientation, and use of space. In a landscape marked by extreme temperatures, jaalis offered a way to inhabit light without being overwhelmed by it.
Unlike glass, which admits light indiscriminately, jaalis filter it. They break harsh sunlight into patterns, reducing glare while maintaining brightness. This filtered light changes throughout the day, creating interiors that respond to time rather than resisting it.
Ventilation is equally important. The perforated surface allows air to pass through continuously, encouraging cross ventilation without fully exposing the interior. This made jaalis particularly effective in dense urban settings and private domestic spaces where openness had to be balanced with discretion.
Privacy was another critical function. Jaalis allowed occupants to observe streets, courtyards, or gardens without being seen. In domestic architecture, especially in regions where social customs required separation between public and private life, this balance was essential. Visibility could be controlled without sealing off space.
Material choice further enhanced performance. Stone jaalis absorbed heat slowly and released it gradually, helping regulate indoor temperatures. Wooden screens responded to humidity and could be adjusted or repaired easily. Clay and lime based constructions worked in tandem with breathable walls.
When European architectural models arrived in India, glass windows were introduced as symbols of modernity. Over time, glass replaced jaalis in many buildings, often without consideration for climate. The result was an increased reliance on mechanical cooling and artificial shading.
Ironically, contemporary architecture has begun to rediscover what jaalis achieved effortlessly. Screens, louvers, perforated façades, and shading devices are now standard elements in climate responsive design. Many of these solutions echo principles long embedded in traditional jaali construction.
What has changed is material and scale, not logic. The idea of controlling light and air through filtration rather than exposure remains central.
Jaalis demonstrate that architecture does not need transparency to feel open. It needs intelligence. They show how boundaries can be porous without being fragile, and how comfort can be achieved through modulation rather than enclosure.
Understanding jaalis as functional architecture rather than decorative heritage reframes how we think about building in warm climates. It reminds us that many challenges addressed by modern technology were once solved through material understanding and careful design.
Before glass walls promised light and openness, jaalis quietly balanced visibility, comfort, and privacy. Their continued relevance lies not in nostalgia, but in their ability to respond to environment with restraint and precision.
They were not replacements for walls. They were refinements of them.