How mud houses in desert city Niger protect against climate change

• Saskia Houttuin

  Africa correspondent

Can houses made of mud protect against climate change? In Agadez, a desert city in the heart of the West African country of Niger, they think so. People have been building here for centuries with ‘banco’: a mud mixture of water, clay and straw.

“The advantage of a banco house is that when it is hot outside, it remains cool inside. And when it is chilly outside, it remains pleasant inside,” says Abdourahman Ibrahim. He is a supervisor who oversees the construction of a house in a new residential area just outside the city.

“This is a modern site,” he says proudly during a tour. “There is electricity, a water connection. I think it is good that we continue to use banco. For our culture, but also for the climate.”

In Niger, old architecture is a solution to new problems

In the area around Agadez, known as the gateway to the Sahara, it is already very hot during the day. But it is getting even hotter, and quickly: due to climate change, the average temperature is rising one and a half times as fast as the global average. Cool nights are becoming increasingly rare, hot days are lasting longer.

The thick walls that surround the mosque of Agadez, among other things, keep out that heat. This place of worship has been a central point of the caravan city for 500 years. Partly because of this, Agadez obtained a place on the World Heritage List of the UN organization UNESCO in 2013. The mosque was rebuilt in the mid-nineteenth century, and since then the 27-meter-high minaret has still been standing, although the building is made entirely of banco.

A matter of maintenance, explains 70-year-old Amma Attouboul. As construction supervisor, appointed by the Sultan of Agadez, he ensures that the mosque remains in good condition. This means that he regularly has the mosque provided with a new layer of banco. As soon as the first cracks or signs of instability appear, they get to work.

“In all kinds of old cities you find buildings made of mud,” says Attouboul. “They belong to our architectural heritage and symbolize a tradition that has endured for generations. This special architectural style is part of the history of Agadez.”

Yet more and more city residents are opting for concrete. Particularly in the suburbs, the sand color of the mud houses is increasingly making way for gray blocks. “It’s like living in an oven,” says supervisor Ibrahim, shaking his head. Concrete does not retain heat or cold as well as banco.

Moreover, it is more expensive. Where banco is made from clay from nearby valleys, cement must be brought in from outside. “People like it,” explains Issoufou Zakari, director of the Regional Authority for Urban Planning and Housing.

A few months ago, Zakari moved to Agadez to tackle rampant construction in the Old Town. He also hopes to convince local authorities and residents to continue to opt for banco.

If it is up to supervisor Ibrahim, the majority of Agadez residents will continue to choose this option. “It’s a source of pride for us,” he says. “Because we live there, our ancestors did the same. And our children will do the same. Banco will always have a future here.”