Mud buildings are remarkably good at keeping us cool in the summer and warm in the winter, and withstanding extreme weather. In the search for more sustainable buildings, architects are returning to this overlooked, age-old construction material.

Mud towers climb high into the sky in Yemen’s historic walled capital of Sana’a. The towering structures are covered in eye-catching geometric designs and made entirely of rammed earth. The ochre-colored mountains in the area mix in with the clay structures. The city of Sana’a has been designated as a Unesco World Heritage Site because of its distinctive mud architecture. Even though Sana’a’s structures date back thousands of years, 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, describes them as “terribly contemporary.” The majority of the historic buildings are still used as private residences today. These mud structures have not lost their attraction because they are incredibly flexible for modern use, well-insulated, and sustainable. It is the future’s architecture, claims 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?