What does it mean to be green? This book, a follow-up to the cult hit XS, is a celebration of idiosyncratic small buildings, and asks what we mean by building 'green' and how doing so enriches the world around us. The projects here are not only about building well, but about seeing well. They embrace the spectrum of small structures from traditional nature huts and ornamental follies, to the charmingly surreal. Buildings that look after people can also be the ones that look after the earth.