Designing sustainable buildings doesn’t always mean hi-tech solutions. From green roofs to living walls to constructed wetlands, sometimes it’s just a matter of embracing natural solutions. Lenny Antonelli investigates the emerging technologies and designs that use nature to improve the performance of buildings.

In this adapted extract from his new book Natural Building: A Guide to Materials and Techniques, seminal eco architect Professor Tom Woolley outlines some of the reasons why natural building is necessary.