Stone and wood are natural materials. They show the mark of the hand that has thought, worked (but not too much) and assembled these materials with skill and care. In this view, both materials are locally sourced by-products of site clearance or road construction.
Glass, an industrial product of sand and heat, shows no sign of human intervention. Glass is used for its transparency to provide light and vision and also here as a negative device to separate solid elements: here, between stone wall and timber door.