Clough Williams-Ellis — later the creator of Portmeirion — argues in Cottage Building in Cob, Pisé, Chalk and Clay for the oldest walls in the world: earth rammed and puddled into cottages that stand for centuries, with the practical detail to build them and the aesthetic case for their revival.
A century later, sustainable builders cite it as a founding text. Download the free EPUB and consider the ground beneath your walls.