This book advocates a new way to build or renovate close to what was known at the time for  green building , a system of building materials with low environmental impact, recycled or recyclable, or removable by simple and inexpensive processes. We will do a tour room by room, from the living room to the bathroom, not forgetting the garden, and we will try to maintain the materials so that they have a long life. We will give priority to environmental and technological measures in the design phase of a home to save water and energy.