Hempcrete Architecture in India: What Portugal's Tiny Coop Teaches Us

A modest chicken coop in São Pedro do Sul, Portugal, is quietly making a loud argument for sustainable construction — one that resonates powerfully for India's rapidly evolving green building sector. Architect Ricardo Leal used hempcrete and timber to build the Pestana Chicken Coop, a compact structure perched on timber columns on a gently sloping site, demonstrating that even the most utilitarian buildings deserve rigorous environmental thinking. Hempcrete — a bio-composite material made from the inner woody core of the hemp plant mixed with lime binder — offers exceptional thermal insulation, carbon sequestration during growth, and near-zero embodied carbon at the point of construction. For India, where the construction sector accounts for roughly 22 percent of total CO₂ emissions and where the government's push toward net-zero buildings is accelerating under the Bureau of Energy Efficiency's Energy Conservation Building Code (ECBC) 2017 and its 2023 updates, Leal's small experiment in Portugal carries outsized implications. With India targeting 500 GW of renewable energy capacity by 2030 under its National Determined Contribution commitments, decarbonising buildings is as urgent as decarbonising the grid.

What Is Hempcrete and Why Does It Matter for India?

Hempcrete is produced by combining shredded hemp hurd — the woody core of Cannabis sativa stalks — with a lime-based binder and water. The resulting material is lightweight, vapour-permeable, thermally efficient, and, critically, carbon-negative over its lifecycle because the hemp plant absorbs CO₂ as it grows. In Leal's Pestana Chicken Coop, hempcrete infill panels sit within a structural timber frame, creating an envelope that regulates temperature and humidity naturally without mechanical intervention. This is precisely the performance profile that Indian architects working in hot-dry climates — think Rajasthan, Gujarat, and parts of Madhya Pradesh — are searching for. Conventional brick and concrete construction in these zones demands heavy air conditioning loads, inflating both energy bills and grid demand. The Bureau of Energy Efficiency estimates that buildings consume approximately 33 percent of India's total electricity, a figure expected to double by 2040 as urbanisation accelerates. Hempcrete walls, by contrast, deliver a thermal lag that keeps interiors cool during the day and releases stored warmth at night, cutting cooling energy demand by an estimated 20 to 30 percent in comparable climates internationally.

The challenge in India is supply chain maturity. Industrial hemp cultivation is legal in Uttarakhand, Himachal Pradesh, and Jammu and Kashmir under state excise regulations, but commercial-scale processing infrastructure for hemp hurd remains embryonic. Organisations such as the Hemp Foundation India and startups like Bombay Hemp Company (BOHECO) are working to change this, but architects wanting to specify hempcrete today face import costs or bespoke sourcing. Leal's project proves the material can perform even in small, structural applications — a proof of concept that Indian pilot projects could replicate at the village and peri-urban scale.

How Sustainable Architecture Is Reshaping India's Built Environment

India's green building footprint is already the second largest in the world by registered area under the USGBC's LEED rating system, and the Indian Green Building Council (IGBC) has certified over 10 billion square feet of green building space as of 2024. Yet the overwhelming majority of these certified buildings rely on conventional materials — concrete, steel, glass — with green credentials earned primarily through energy-efficient systems and renewables integration rather than low-embodied-carbon material choices. This is beginning to shift. The National Institute of Advanced Studies in Architecture (NIASA) and institutions like CEPT University in Ahmedabad are incorporating bio-based materials including bamboo, compressed earth blocks, and increasingly, hempcrete into their curricula. State governments in Uttarakhand and Himachal Pradesh have explored hemp-based construction for rural housing as a way to simultaneously support local agricultural income and reduce the carbon intensity of new builds. Meanwhile, the Ministry of Housing and Urban Affairs' PM Awas Yojana Urban 2.0 scheme, targeting 10 million urban homes, represents a massive opportunity to embed low-carbon materials standards into affordable housing procurement at scale.

Ricardo Leal's instinct — that even the most modest structures deserve careful thought — is a design philosophy that maps directly onto India's challenge of building hundreds of millions of square metres of new floor space over the next two decades while keeping embodied and operational carbon in check. Tier-2 cities such as Indore, Coimbatore, Surat, and Nashik are experiencing construction booms where material choices made today will lock in carbon emissions for fifty years or more. Architect-led pilot projects using hempcrete, rammed earth, or bamboo composites in these cities could demonstrate scalable alternatives before concrete becomes the irreversible default.

What This Means for India's Energy Transition

India's 500 GW renewable energy target by 2030 dominates energy headlines, but the built environment is an equally critical battleground. Every building constructed with high-embodied-carbon materials is a liability on India's net-zero pathway, because operational clean energy cannot fully offset the carbon already emitted during construction. Integrating bio-based materials like hempcrete into mainstream Indian construction codes — through the ECBC, the National Building Code, or green procurement mandates under Smart Cities Mission projects — would align the architecture sector with the broader clean energy transition. The MNRE's focus on solar and wind is essential, but decarbonising construction materials is the complementary lever that Indian policy has yet to pull decisively.

Watch for three developments in the next 12 to 18 months: whether Uttarakhand's hemp cultivation programme expands its processing capacity to enable local hempcrete production at commercial scale; whether IGBC introduces a material carbon rating alongside its existing energy performance metrics; and whether any of India's major real-estate developers — Godrej Properties, Mahindra Lifespace, or Sobha — pilot a hempcrete demonstration block in their sustainability-positioned product lines. A Portuguese chicken coop has set the bar. India's architects now need to raise it.