The project’s sloping walls and vegetated ramps hide a sizable home. The grey concrete further reduces the home’s visual impact and tucks the envelope behind a lush green facade. The planted exterior continues up top on a massive scale — the green roof is the sustainable star of the home, reducing the heat from the intense Spanish sun. It also provides habitat for animals while filtering rainwater runoff. Black boxes on the roof are solar thermal hot water tubes for domestic hot water.