Sustainable earthen materials have many benefits, but the dominant stigma against ‘mud bricks’ and limited scientific scrutiny prevents their widespread adoption.

• Building materials made of earth are to be studied by Bath engineers as a carbon-saving option for the construction industry
• They are easy to procure and can be produced more efficiently than steel or concrete
• They provide natural cooling and humidity control, replacing the need for energy-sapping air conditioning systems
• Earthen materials are already marketed as high-end design choices in urban India, but are stigmatised in the West, and also in rural India where they have sustained for centuries
• WAFER project set to investigate how they could be marketed, with a focus on indoor wellbeing benefits

Engineers at the University of Bath and the Indian Institute of Science are jointly set to investigate how to create bricks, paints and other building materials from earth, in an effort to make our homes more sustainable with improved indoor health and wellbeing.

The Wellbeing Achieved from Earthen Residences (WAFER) project, run by academics in the University’s BRE Centre for Innovative Construction Materials and IISc’s Centre for Sustainable Technologies, have started work to investigate the viability of earth as an environmentally benign and affordable building material, with the aim of reducing carbon emissions associated with the construction industry.

While earthen materials have a low impact on the environment and can improve indoor air quality, they are rarely adopted in the modern world as social status is associated with materials considered ‘modern or developed’, such as concrete, glass and steel. Such materials, however, are highly carbon-intensive and do not promote indoor wellness.

The WAFER project team, based in Bath and the Indian Institute of Science, will investigate the cultural and social sensitivity associated with earthen materials. With scientific scrutiny, their potential health, wellbeing and environmental performance would reinstate faith in their adoption for modern constructions, particularly housing demands.

Dr Dan Maskell, a lecturer in the Department of Architecture & Civil Engineering and the project’s principal investigator, says that if they can be effectively marketed, natural materials could become a well-respected trend in house building and design. He says: “When people hear of this project, they might think we’re recommending people live in mud huts. That incorrect perception is something we’ll investigate, so it can be overcome.

“People think that ‘modern’ materials like steel and concrete are best, but producing them and living in these buildings uses huge amounts of energy and carbon, so the case for using natural materials is strong. We need to understand how to change negative perceptions of these materials if we’re to reduce the environmental impact of the construction industry.”

Natural materials  to improve indoor air quality

Dr Maskell says that the construction of many modern homes – or adaptations made to older ones – has created indoor air quality problems that earthen materials could alleviate. He explains: “Design thinking over the past 30 years has sought to make homes and buildings as airtight as possible. Inadequate ventilation means we’re breathing poor-quality air much of the time we’re at home.”

Earthen materials can act as natural ‘passive’ air conditioning, by absorbing harmful elements from the air and regulate indoor moisture for improved well-being. The project team will investigate how this could provide a selling point, by appealing to an increasing awareness of indoor air quality. This study is particularly relevant given the current COVID-19 pandemic, where air-conditioning is being avoided to avoid spread of infections.

“Earthen materials, potentially in the form of bricks or paints, can work like a natural air cleaning system so the potential for these products as a health and sustainability choice are huge,” Dr Maskell adds. They are easily accessible and concerns associated with end-of-life are almost non-existent when compared with other energy-intensive industrialized building materials.

“They’re natural, less impactful than many materials currently in use, and you can even legitimately describe them as nano-materials given the scale at which the air-quality regulating mechanism actually operates, to appeal to tech-conscious buyers.”

International perspective crucial

Potential market appeal is critical to the new products created through the WAFER project. This will be investigated through the collaboration with colleagues at the Indian Institute of Science – as Indian consumers’ views of earthen materials differ from those of Western consumers.

In India, expensive, high-end new properties are being marketed as using earthen materials as there is a greater familiarity and understanding of their benefits. Exploring the mindset of homebuyers and housebuilders in relation to these materials is important to promoting them effectively, says Dr Maskell.

He adds: “We also need to make sure that people understand the versatility of these materials – for example, that they can be made in all sorts of colours, to appeal from an interior design viewpoint.”

The WAFER project will be carried out by Dr Maskell and colleagues from Bath’s BRE Centre for Innovative Construction Materials (BRE CICM) including Dr Juliana Calabria-Holley, Professor Sarah White and Professor Pete Walker. Professor Monto Mani and Professor Venkatarama Reddy from the Indian Institute of Science will also work on the project.

The British Academy has provided the WAFER project £299,649.09 in funding over the next three years.

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