By Isabelle Gerretsen

1 In Yemen’s ancient walled city of Sana’a mud skyscrapers soar high into the sky. The towering structures are built entirely out of rammed earth and decorated with striking geometric patterns. Sana’a’s mud architecture is so unique that the city has been recognised as a Unesco World Heritage site.

2 gnised as a Unesco World Heritage site. “As an outstanding example of a homogeneous architectural ensemble reflecting the spatial characteristics of the early years of Islam, the city in its landscape has an extraordinary artistic and pictorial quality,” Unesco writes in its description of Sana’a. “The buildings demonstrate exceptional craftsmanship in the use of local materials and techniques.”

3 Even though the buildings in Sana’a are thousands of years old, they remain “terribly contemporary”, says Salma Samar Damluji, co-founder of the Daw’an Mud Brick Architecture Foundation in Yemen and author of The Architecture of Yemen and its Reconstruction. The ancient structures are still inhabited today and most remain private residences. Damluji says it is easy to see why these mud buildings have not lost their appeal – they are well-insulated, sustainable and extremely adaptable for modern use. “It is the architecture of the future,” says Damluji.

4 Architects around the world are reviving raw-earth construction as they seek to construct sustainable buildings that can withstand extreme weather events such as flash floods and intense heat. Could this ancient form of architecture influence the design of our future homes and cities? Could this back-tobasics technique provide an important solution to the climate crisis?

5 The construction industry accounts for 38% of global carbon dioxide emissions. The building sector has an important role to play if the world is to meet its goal of reaching net zero by 2050 and keep global temperature rise below the critical threshold of 1.5C. Swapping concrete for less polluting materials is critical to achieving our climate goals, scientists warn. Concrete, a staple of modern construction, has a huge carbon footprint.

6 “We cannot live in these concrete jungles anymore,” says Damluji. “We have to consider the environment and biodiversity. We cannot construct in isolation.” Mud could be the perfect sustainable alternative to concrete, according to Damluji. Constructing with mud has a very low impact on the environment and the material itself is fully recyclable, she says.

7 The ancient building practice is inspiring modernday architects, such as Serbian Dragana Kojičić, who specialises in raw-earth construction. “Our ancestors were really clever and really practical – they used what they had around them,” says Kojičić. “The earth was everywhere and it could be used for everything: walls, floors, ceilings, stoves and even roofs.”

8 ls, floors, ceilings, stoves and even roofs.” Kojičić, who completed her training at the Centre for the Research and Application of Earth Architecture, restores and builds earthen houses across Serbia, reviving ancient building methods. “Mud is contagious – it is love at first touch,” she says. You don’t need to wear any protective gear when handling the material, she adds. “With earth, you can just play.

9 Anna Heringer, an Austrian architect who creates buildings using natural materials such as mud and bamboo, agrees. “It is a wonderful feeling to touch the earth,” she says. “You don’t need any tools to build with it, you just use your hands.”

10 Heringer has been working with mud for almost 20 years and has designed many notable earthen buildings, including the METI handmade school in Rudrapur, Bangladesh, for which she received the Aga Khan Award for architecture in 2007. “Mud is a very inclusive material; poor and rich can build with it,” she says.

11“Mud is the champion of future sustainable construction,” says Heringer. “It is the only material we can recycle as often as we like, without using any energy,” she says. “It actually gets better the more you use it.” It’s a bit like a dough, Heringer says – as you work with it, the material changes and responds.

12 But using mud for construction should be done in a sustainable way and should not reduce land availability for growing crops, says Trevor Marchand, emeritus professor of social anthropology at London’s School of Oriental and African Studies. “It can be a solution, but only on a certain scale,” he says, noting that the global population is expected to reach 9.7 billion people by 2050, mounting pressure on land.

13 People who wish to live in a modern, comfortable home should consider one made of mud, architects say. “Mud buildings are extremely adaptable,” says Damluji. “If you want to pull a wall down or change the design, you can recycle all the materials.”

14 Overall, this makes for highly sophisticated as well as sustainable design, says Pamela Jerome, a US architect and president of the Architectural Preservation Studio, which focuses on restoration projects around the world. “Every mud house is comfortable, can be totally adapted and easily retrofitted with electricity and plumbing.”

Available at: https://www.bbc.com/future/article/20220705-the- -sustainable-cities-made-from-mud - Retrieved on: July 18, 2022. Adapted.

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