History of jali: from carved stone to GRC

What “jali” means

The word jali (also jaali) means net or lattice in Hindi and Urdu. In architecture it describes a screen pierced with a repeating pattern of openings: geometric stars and polygons, floral scrolls, or calligraphy. The closely related jharokha is an overhanging, enclosed window, often itself filled with jali.

Why builders used jali

The jali was a climate device first and an ornament second.

• Glare and heat: small openings break harsh sunlight into soft, dappled light and cut solar gain into rooms.
• Ventilation: air keeps moving through the screen.
• Privacy: from the bright outside you see the pattern, not the interior, while people inside can see out. This mattered in palaces, homes and zenana quarters.
• Meaning and beauty: geometry, flowers and script carried religious and cultural symbolism, and the moving shadows became part of the architecture.

Landmark jalis in India

A few well-documented examples show how far the craft developed:

Building	Place and date	Why it matters
Sidi Saiyyed Mosque	Ahmedabad, completed 1572–73	Its carved stone “tree of life” jali is among the most famous in the world and has become a symbol of Ahmedabad.
Tomb of Salim Chishti	Fatehpur Sikri, late 16th century	Delicate white marble screens enclose the tomb, showing the Mughal mastery of geometric jali.
Taj Mahal	Agra, 17th century	An octagonal pierced-marble screen inlaid with stones surrounds the cenotaphs.
Hawa Mahal	Jaipur, built 1799	A five-storey façade of 953 small windows (jharokhas) with latticework let royal women watch the street unseen while breezes cooled the rooms.

Stone jali appears across the subcontinent, from Gujarat’s Sultanate mosques to Rajasthan’s havelis, in local sandstone, marble and wood.

Why stone jali became rare

In the 20th century jali largely disappeared from everyday buildings. Hand carving is slow and expensive, stone is heavy, and frame construction with glass windows and, later, air conditioning made screens seem unnecessary. Cheaper substitutes appeared: cement “jali blocks”, terracotta screens and, later, metal and laser-cut panels. Architects such as Laurie Baker revived brick and terracotta jali walls as a low-cost way to cool buildings, keeping the idea alive.

How GRC made jali practical again

The key invention had nothing to do with India. Ordinary glass fibre had been tried as reinforcement for cement but was slowly destroyed by the cement’s alkalinity. In the late 1960s the UK’s Building Research Establishment developed an alkali-resistant (AR) glass containing zirconia, and Pilkington began producing it commercially as Cem-FIL in the early 1970s. With AR fibre, cement could be reinforced without steel and cast thin. That was glass fibre reinforced concrete, or GRC.

For jali, GRC solved the old problems at once:

• Weight: a 30–35 mm GRC jali weighs a fraction of a carved stone screen of the same size, so it can go on upper floors and slab edges.
• Cost and speed: one master pattern and mould can produce hundreds of identical panels.
• Durability: no steel to rust, no timber to rot, and the material is non-combustible.
• Freedom of design: traditional Mughal geometry and modern parametric patterns are equally easy to cast.

In recent decades GRC jali has spread across India on hotels, institutions, temples and, increasingly, homes. We have cast it since 2012 for projects ranging from private residences to Taj Palace, New Delhi and power projects of NTPC and NPCIL.

What modern jali can learn from the originals

• Put it where the sun is. The old builders used jali on hot façades and courtyards, not everywhere. West and south elevations benefit most.
• Size the openings for the job. Fine patterns for privacy, larger openings for airflow.
• Depth matters. A deeper screen casts more shade when the sun is at an angle, which is part of why carved stone jalis worked so well. A 30–35 mm GRC jali keeps much of that effect.
• Pattern should suit the viewing distance. Palace jalis are fine near eye level and bolder high up. That still holds on a modern elevation.

Thinking about a jali for your building? Our complete GRC jali guide covers design, thickness, cost and fixing.

Frequently asked questions