BBC Future Planet reports:

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. The earthen buildings blend into the nearby ochre-coloured mountains.

Sana’a’s mud architecture is so unique that the city has been recognised 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.”

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.

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-to-basics technique provide an important solution to the climate crisis?

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. Building with concrete accounts for around 7% of global CO2 emissions – substantially more than the aviation industry which is responsible for 2.5% of emissions. Worldwide 4 billion tonnes of cement, the key component of concrete, is produced each year.

“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. [Continue reading…]