India has always been the pioneer in inventing things, which also applies to eco-friendly building materials. Presently, in the 21st century, where we are aiming for our construction to be more sustainable and eco-friendly, there has been a shift towards the latest and most eco-friendly building materials. Whether it is laying the foundation of philosophy by giving us the Vedas or inventing numbers, India was already exploring and continues to explore eco-friendly building materials around 2600–1900 BC.

In India, there are different eco-friendly building materials based on the different climate zones. The shift has not only been in using eco-friendly building materials; there is a shift in the construction methods we use for them as well.

We will go through the 20 latest eco-friendly building materials below:

20 Latest Eco Friendly Building Materials

1. Sandbags

These sandbags, made of burlap and filled with sand or soil, are inexpensive and widely available. They are highly eco-friendly because they use the vast amount of sand that is readily available on the sites. Their eco-friendly quality increases because of them, leading to a low carbon footprint and being thermally effective in the building. Sandbags can also be stacked like masonry and plastered over. However, it may cause potential contamination issues when used in flood control.

2. Bamboo

Bamboo is a versatile, eco-friendly building material. Renewable, eco-friendly material is widely available because of its rapid growth. Its flexibility and good tensile strength make it suitable for a variety of construction techniques.

Bamboo is also used for building scaffolding, bridges, and various other structures. Though it’s sustainable, it is susceptible to environmental conditions like moisture, which can lead to rotting.

3. Fly Ash Bricks

This material is quite unique because it was the byproduct of managing the environmental problems caused by fly ash by reducing mercury pollution. The production of fly ash bricks comprises of class C or class F fly ash, water, quicklime, cement, aluminium powder, and gypsum. These components are compressed at high pressure and cured in a steam bath, which results in durable bricks.

These bricks are lighter and stronger than traditional clay bricks. Although the construction of fly ash bricks is similar to traditional bricks, their finish may not be as smooth.

4. Cork

Cork is a naturally eco-friendly material, harvested and carefully removed from the bark of cork oak trees. It is an ancient material harvested in Mediterranean regions. The sustainable method of harvesting cork makes its production environment friendly. It is mainly used for insulation purposes on walls, floors, ceilings, and facades.

Cork granules can also be mixed into concrete, creating lower thermal conductivity and lower density. Though it may not be a primary structural material, it enhances the structural properties. Cork is potentially more expensive as compared to other insulation materials.

5. Terracotta

Terracotta’s origins trace back to various cultures like Greek, Babylonian, Egyptian, Roman, Chinese, and Indus Valley civilizations. It was produced by ether-pouring or pressing a clay mix into moulds, which were later air-dried and fried in a kiln for several days. Recently, considering the inception of structural metal, terracotta finds its use in anchoring systems. It was then well known as laying directly into masonry with the advent of structural elements.

In the 19th century, terracotta began its use in connection with metal anchoring systems as a fireproof and lightweight cladding material. This eco-friendly material is usually a hollow material with metal frame attachment or with masonry walls with different anchors.

6. Low VOC paint

Low-VOC paint, also known as Volatile Organic Compound is a type of paint introduced in 1992. Since it was more expensive than traditional coatings, it didn’t gain immediate popularity.

The low-VOC paints come in a range of colours, and they sit while selecting paints for interior projects. The major benefits of this eco-friendly material are that it is environmentally friendly and has minimal odour. It does have a higher price and shorter longevity, but it is safer for people who apply for it and those who apply for the space.

7. Linoleum Flooring

This eco-friendly material is known for its durability and environmental friendliness. Linoleum, first invented by Fredrick Walton in 1860, was discovered to have the potential to solidify linseed oil for flooring materials. Linoleum sheets are laid over any level and then glued with water-based adhesive, which is later flattened with heavy rollers.

Another way is to use them as tiles with click-together pieces with slightly different installation processes. There are various ways of manufacturing linoleum, which makes it an excellent renewable and recyclable material. The only downside is that it is not waterproof and needs resealing every five years.

8. Jute Fiber

Jute fibre has an ancient history that traces back to the 3rd millennium BC, right from the Indus Valley Civilization. This eco-friendly material is one of the most affordable natural fibres and thrives in tropical lowland areas. About 95% of the world’s jute is obtained from India and Bangladesh. Adding jute to reinforce concrete enhances its compressive as well as tensile strengths.

There are a few cons to jute fibre as an eco-friendly material. Those are its lack of flexibility, a decline in strength when exposed to water, and its absence of lustre. In spite of all of this, jute fibre is a versatile and eco-friendly material that is easily grown and provides major support to concrete if used in optimal quantities.

9. Coir

This eco-friendly material is obtained from the most versatile fruit, coconut. In addition to being used for centuries to make ropes and cordages, coir has a high water-holding capacity. It is mainly used as a reinforcement in cement or as a replacement in aggregates. It has the latest trending use because of the shift towards green and efficient buildings, where it has composite use for wrapping beams and structures.

Coir wood, derived from coir fibre, is a substitute for plywood for door and window frames. Since coir has a lot of salt content, it requires washing it out (a process called leaching). This eco-friendly material is gaining popularity in geotextiles for helping with the prevention of soil erosion.

10. Rammed Earth

This highly sustainable, eco-friendly material dates back to 5000 BCE. Used initially by the Neolithic civilization, rammed earth is a result of compacting a damp mixture of subsoil and appropriate proportions of sand, gravel, clay, and silt. Rammed earth is locally available and encourages cultural preservation. It does require careful design in humid regions and has a slower building process.

11. Hempcrete

Hempcrete is an eco-friendly building material that uses the inner woody core of the hemp plant with a lime-based binder and water. This mixture is then shaped into blocks and set for curing, later loaded into pallets, and finally delivered to the site. The use of hemp in construction is not new to India.

Companies like GoHemp are researching and developing hempcrete as a sustainable building material. Hempcrete is lightweight, reduces carbon footprints, improves insulation, and does not emit any harmful byproducts after curing. Though it is a sustainable and renewable material, India lacks a robust hemp industry.

12. Recycled Steel

India currently produces 30 million metric tonnes of recycled steel annually, with its use predominantly in construction, infrastructure sectors, and automobiles. The scraps undergoes processing through various methods, including Electric Arc Furnaces (EAF).

Tata Steel has a state-of-the-art steel recycling plant in Haryana, which uses equipment like balers, shredders, and material handlers. There are challenges in importing scrap, which causes irregularities in prices.

13. Mud Bricks – Adobe

The production of the eco-friendly material is relatively simple and cheaper, as its primary raw material is clay. Adobe is actually Spanish for Mud Bricks, and its construction dates back to around 5000 BC.

Stabilisers like husk, straw, lime, and cow dung enhances the properties of Mud bricks. The proof of their resilience is in areas like Earthquake-prone Kutch and flood-affected regions of Rajasthan. Their surfaces are not that smooth, and they have lower strain resistance. Mud bricks are one of the best eco-friendly materials due to their thermal insulation, stability, and the fact that they are recyclable and reusable, which in turn reduces the cost.

14. Rice Husk Ash

India contributed to the highest number of rice products and rice husk production in 2023. The production of RHA (rice husk ash) is done traditionally by burning in the open air, which causes a lot of air pollution. The type of burning is dependent on the type of husk. There is also fluidized burning and one with an industrial furnace.

RHA is rich in silicates, which, upon reaction with calcium hydroxide (while making cement), increase durability and present higher tensile strengths when mixed in a specific proportion. Other than its uses in cement, it has also been used in industrial factory flooring, waterproofing, ceramic glaze, and roofing shingles.

15. Ferrock

The main issue with concrete is that it emits around 10% carbon dioxide. This eco-friendly material, Ferrock, is an iron-based binding compound that uses a variety of waste materials, such as steel dust and silica. It uses iron dust, which would either way have been wasted, and uses it to create carbon-negative footprints.

Though no one knows the entirety of the life cycle of Ferrock, it is chemically inactive and doesn’t deteriorate on explosion to gases or chemicals. Even though it is around five times stronger than cement, its main advantage that benefits the environment is that it absorbs carbon dioxide during production.

16. Permeable Concrete

Permeable concrete, also known as pervious concrete, is a mixture of cement, coarse aggregates, and water. It is a structural concrete pavement that contains little to no sand, which causes a porous open-cell structure to let the water pass easily. This eco-friendly material not only helps the flow of the water take place at a higher rate but also helps with the filtration of the water. This system was first seen in the 1800s in Europe.

Permeable concrete is gaining attention as an eco-friendly material for construction. A notable example of its use is ‘Pervious Concrete Road Pavement’ at Katedan Sports Complex in Hyderabad, spanning 20 metres with a width of 6 metres. This helped in improving rainwater recharge as well as constructing low-loading-intensity parking pavements, footpaths, and walkways. However, they are not as strong as traditional or asphalt pavements, which makes areas with heavy traffic unsuitable for them. This eco-friendly material does not produce a ‘heat island’ and remains cool in summer due to water circulation and its lighter colour.

17. Solar Tiles

Solar tiles, or solar shingles, are made from solar cells using semiconductors. Arranging materials like silicon and selenide into bands or strips can create shingles or tile shapes. India’s residential rooftop solar capacity, as of March 2022, was 2010 MW. That’s a huge amount of possibility for solar harvesting.

Companies like APL Apollo Tubes and Ornate Solar are taking initiatives to transform conventional solar panels into primary roofs. This implementation, when applied to industrial and commercial buildings, will be just the right approach to harvesting solar capacity and meeting the Indian market’s needs and conditions.

TERI (The Energy and Resources Institute) has a project dedicated to solar rooftop installations, aiming to enhance their rooftop solar capacity. They also aim to provide end-to-end services in solar installations. MNRE (Ministry of New and Renewable Energy) aims to achieve a cumulative installed capacity of 40,000 MW from rooftop solar projects.

18. Straw Bale

Straw is not a new building material in India. This eco-friendly building material was widely used in roofing as a thatch. However, the use of straw bales in contemporary construction is not yet popular in India, despite the country being the largest area for rice cultivation. Farmers often burn the residual straw to clear the fields for the next crop, leading to environmental issues. Thus, utilising straw as a building material would make it one of the best eco-friendly materials.

The construction of straw bale walls involves compacting the bales to form cuboidal units, laying them next to each other, and applying a lime-based plaster for the exterior. Straw bale is susceptible to moisture and decay. It is heavy as well and needs protection during construction. In spite of all this, this eco-friendly material offers excellent thermal and sound insulation. It has high tensile strength and is suitable for affordable and energy-efficient housing.

19. Reclaimed wood

Reclaimed wood is old lumber recycled or repurposed for use in new projects. These are often retrieved from old buildings, bungalows, barns, or homes. It goes through various processing steps to ensure its integrity and shape are preserved for new construction projects. This is not a new concept, but the recent popularity of this eco-friendly material has made it more challenging to source it. Kerala is using reclaimed wood to build a new house completely.

Reclaimed wood can be more expensive than new wood due to the intensive labour and processes involved in recycling. Regardless of this, this eco-friendly material contributes to reducing deforestation. At times, since these woods come from older trees, they are more durable. They also achieve unique appearances and can contribute to LEED certifications.

20. Wool Insulation

Wool insulation is created from sheep wool fibres that are either mechanically held together or bonded with 5-20% recycled polyester adhesive. These are then formed into batts, rolls, and ropes.

The application of wool insulation is similar to the conventional one. It is a versatile, eco-friendly material and is generally more expensive than fibreglass and mineral wool. The chemicals used for its production are toxic, and wool retains a natural odour, which can be sensitive to some people. Regardless, wool is soundproof, flame-resistant, and helps with temperature control.

Conclusion:

This list makes one wonder how many of us we see when we step out of our house. We are thrilled to be a sustainable architect and a sustainable person. Do you know how I see sustainability? I see it as using the same dress twice. That dress is made of eco-friendly material. To make a building thrive, some are hollowed out, and some are made directly out of dirt. through the storms and winds, through the drought and floods.

It is noteworthy that none of these Eco-friendly building materials have compromised their approach towards sustainability which moving away from a vernacular side. They are modern, need of the hour and most importantly efficient. Architects have learned the sizes of beam depth, sill, and lintel height. We know how to get from our design because we are so well-versed in cement, concrete, and steel. Is that what keeps us from putting our other leg in the future and embracing these Eco-friendly building materials?

Content Writing And Research By: Ar. Lekha More