The Future of Sustainable Architecture

Sustainable architecture is the practice of designing buildings that use less energy, water and material over their whole life while keeping occupants healthy and comfortable. In India, it means designing for the local climate first, using passive cooling and daylight, choosing low-carbon materials, and meeting codes such as ECBC 2017 and rating systems like IGBC and GRIHA.

What does sustainable architecture mean in the Indian context?

India's National Building Code 2016 classifies the country into five climate zones: hot-dry, warm-humid, composite, temperate and cold. A sustainable building in Jaisalmer and one in Mumbai should look very different, because the first must manage intense dry heat and large day-night swings while the second must handle humidity, heavy monsoon rain and salt-laden air. We start every project by reading the climate, the sun path and the prevailing winds before we draw a single plan.

Many of the best strategies are not new. Courtyards, jaalis, deep verandahs, thick masonry walls and stepwells were all climate responses long before air conditioning existed. The future of sustainable architecture in India is largely about combining that inherited knowledge with modern materials, better glazing and accurate energy modelling.

Which codes and rating systems apply to green buildings in India?

The Energy Conservation Building Code (ECBC) 2017, published by the Bureau of Energy Efficiency, sets minimum energy performance standards for commercial buildings, with higher tiers called ECBC+ and SuperECBC. For homes, the Bureau of Energy Efficiency also published the Eco-Niwas Samhita, which focuses on the building envelope of residential projects.

Voluntary rating systems help owners prove performance. The Indian Green Building Council (IGBC) and GRIHA, developed with The Energy and Resources Institute (TERI), are the two most widely used in India. Several states and municipal bodies offer incentives such as additional floor area or faster approvals for rated projects, so we recommend checking local rules early in design.

Which passive design strategies save the most energy?

Passive design reduces energy demand before any equipment is installed, which makes it the cheapest form of sustainability. In most Indian climates, keeping heat out is more important than keeping it in. The strategies we rely on most are:

• Orientation: place the longer facades north and south, and limit glazing on the west, which receives harsh afternoon sun.
• Shading: horizontal overhangs of roughly 600-900 mm work well on south facades; vertical fins or jaalis suit east and west.
• Cross-ventilation: openings on opposite walls, with outlets equal to or larger than inlets, let breezes flush out heat.
• Roof insulation and cool roofs: high-reflectance finishes or 50-75 mm of insulation significantly reduce heat gain through the top floor.
• Daylighting: light shelves, clerestories and a sensible window-to-wall ratio reduce daytime lighting loads without adding glare.
• Thermal mass: in hot-dry and composite zones, thick walls of brick or stone delay heat entry until the cooler evening.

In warm-humid cities like Mumbai and Chennai, thermal mass is less useful because nights stay warm. Here we prioritise shading, ventilation and lightweight, well-insulated roofs.

Which low-carbon materials are available in India?

Embodied carbon, the emissions from making and transporting materials, can be a large share of a building's lifetime footprint. India has a growing range of lower-carbon options that are easy to source:

• Fly ash bricks and AAC blocks, which reuse industrial by-products and insulate better than solid clay bricks.
• Compressed stabilised earth blocks, made close to site from local soil.
• Portland pozzolana cement (PPC) and blended cements with slag, instead of plain OPC where structurally appropriate.
• Locally quarried stone such as Kota, Shahabad or basalt, which needs little processing.
• Bamboo, lime plaster and reclaimed timber for interiors and secondary structures.

The greenest building is the one designed so carefully for its climate that it barely needs machines to stay comfortable. – Pranav Kadoo

— Pranav Kadoo

How will sustainable architecture change over the next decade?

Sustainable architecture is shifting from individual green features to whole-life performance. Owners increasingly want buildings that are measured, not just certified, so we expect energy metering, smart controls and post-occupancy evaluation to become standard on mid-size projects.

Rooftop solar is now common on Indian homes and offices, and net-metering policies in many states make it financially attractive. Rainwater harvesting is already mandatory for larger plots in many Indian cities, and greywater recycling for flushing and landscape irrigation is becoming more common in apartment complexes. We also see growing interest in adaptive reuse, because retaining an existing structure avoids most of the embodied carbon of a new one.

Climate resilience will matter as much as efficiency. Buildings in coastal and flood-prone areas need raised plinths, corrosion-resistant detailing and designs that remain usable during power cuts and heatwaves.

In short: key takeaways

• Design for your climate zone first; passive strategies cost the least and save the most.
• Use ECBC 2017 and Eco-Niwas Samhita as baselines, and IGBC or GRIHA to verify performance.
• Shade the west, ventilate across the plan and insulate the roof.
• Choose low-carbon Indian materials such as AAC blocks, fly ash bricks, blended cement and local stone.
• Plan for solar, rainwater harvesting and resilience from day one rather than adding them later.