Author – Varsha Arun

In a world increasingly aware of construction’s environmental impact, how we build has taken on new meaning—it reflects our values and response to the planet. Gone are the days when concrete and steel were the only options.

Today, sustainable building practices are leading the way, offering innovative, eco-friendly, and cost-effective solutions. From time-tested traditional methods to cutting-edge innovations that tackle waste, these eco-friendly wall building techniques are transforming construction. Whether you’re building a cosy cottage, a modern home, or a community space, incorporating eco-friendly wall-building methods reduces your carbon footprint and creates healthier, energy-efficient living environments that are symbiotic and responsive to their surroundings. Let’s explore some of these eco-friendly wall building methods.

Why Choose Eco-Friendly Wall Building Techniques?

1. Environmental benefits: Eco-friendly wall-building techniques use renewable or recycled materials, reducing the demand for energy-intensive materials like cement and steel. This lowers the carbon footprint of construction and helps combat climate change.
2. Waste reduction: These techniques minimizes construction waste that would otherwise end up in landfills or oceans.  The waste can be repurposed or biodegraded even after a building’s lifespan.
3. Cost-effectiveness: Many traditional and lightweight materials are locally available and affordable, making them ideal for low-cost housing projects. Techniques like cob, adobe, and wattle and daub require minimal machinery, further reducing costs.
4. Finished product: Most of these techniques require little to no further finishing as they are the end product, thus reducing the cost of construction further.
5. Energy efficiency: Materials like mud and hempcrete have excellent thermal insulation, keeping homes cool in summer and warm in winter. Traditional vernacular homes rarely needed air conditioning, but rapid urbanization and a lack of knowledge in sustainable building techniques have led to increased dependence on ACs as a quick fix for rising urban temperatures. By reducing the need for artificial heating or cooling, these methods save energy and cut costs.
6. Cultural relevance: Traditional techniques like stone masonry and adobe bricks are deeply rooted in our architectural heritage, blending cultural identity with sustainability.
7. Health and comfort: Natural materials like clay, bamboo, and hemp are non-toxic and breathable, creating healthier indoor environments. They also regulate humidity, improving comfort levels.

Traditional Knowledge from the Hinterlands

• Cob – An ancient building technique, cob involves hand-sculpting walls from a mix of clay, sand, straw and other local organic binding materials, mixed with water, which are then left to dry naturally. Known for their thickness, cob walls offer exceptional thermal insulation, making them perfect for India’s diverse climates. They are also fire-resistant and fully biodegradable, embodying true sustainability.
• Wattle & daub – This traditional method involves weaving bamboo or wooden strips (wattle) into a lattice and then plastering it with a mixture of mud, clay, orstraw (daub). Wattle & daub walls are lightweight, breathable, and are well-suited for rural and semi-urban areas. They are also cost-effective and easy to construct.

• Stone masonry – Stone masonry can trace its origin as far back as 10,000 BCE with ancient stone walls seen in Jericho and Malta. It involves stacking local stones bonded with lime or mud mortar, creating strong, durable, and naturally cooling walls. It requires minimal maintenance so it is still widely used in hilly regions like Himachal Pradesh and Uttarakhand where stone is abundant. However, stone walls are thick, demanding space, and the hardness of stone makes electrical and plumbing installations challenging. Creating openings for doors and windows also requires strong lintels to support the heavy walls above. So stone walls are best suited for foundations, boundary walls, or feature walls where their primary purpose is simply to ‘be a wall.’
• Rammed earth – One of the most visually striking and sustainable wall construction methods, rammed earth involves compressing a mix of earth, gravel, sand, and a small amount of cement or lime into formworks, creating durable and energy-efficient walls. By adding dyes, walls can showcase beautiful waves of earthy tones, offering a unique aesthetic. The soil used is typically sourced directly from the construction site, and its natural hue determines the final colour of the wall. While rammed earth requires skilled labour to prevent early cracking, its eco-friendly appeal and natural beauty is making it increasingly popular in modern sustainable homes across India.
• Adobe bricks masonry – Another way to use site soil is by creating adobe bricks. Made by mixing the soil with straw or organic materials, these blocks are sun-dried to gain strength before being stacked and bonded with mud mortar to build walls. Adobe walls excel in thermal regulation, making them ideal for arid regions like Rajasthan and Gujarat.

• CSEB blocks masonry – Compressed Stabilized Earth Blocks (CSEB) are produced by machine-compressing a mix of soil, sand, and a small amount of cement or lime. For sites lacking suitable soil, these blocks can be sourced directly from manufacturers. Stronger than adobe bricks, CSEBs are ideal for load-bearing walls and offer a sustainable alternative to conventional bricks. Evidently, they are now widely gaining traction in both rural and urban areas.
• Clay bricks masonry – Made from baked clay, these bricks have been used in India for centuries. They are durable, fire-resistant, and provide good thermal insulation. Traditional clay bricks are eco-friendly, but modern kiln-fired bricks can have a higher carbon footprint, so sustainable sourcing is important. A newer type, wire-cut bricks, is made using machines that cut long clay columns into precise, smooth bricks. These are often used for walls that are left exposed, giving a neat, modern look compared to traditional uneven bricks that are often plastered over.

• Porotherm blocks masonry – Porotherm blocks are lightweight and hollow clay blocks known for their energy efficiency and thermal and sound insulation. With good compressive strength, they are ideal for urban construction and are more eco-friendly than conventional bricks due to lower energy consumption during production. However, cutting these hollow blocks for conduits or adjustments can be challenging, since they are prone to breaking if not handled carefully.
• Laterite stone masonry – Laterite is a porous stone found in coastal regions like Kerala, which is ideal for wall construction in hot, humid climates. It regulates moisture, keeps interiors cool, and hardens over time, becoming durable and cost-effective. Cut into blocks, it can be used directly, compacted like CSEB, or fired like clay bricks. However, its porous nature makes it less suitable for freezing climates or extreme rain weather, and its regional availability limits widespread use.