Building Ecology: First Principles for a Sustainable Built EnvironmentBuildings consume 40% of our planet's materials and 30% of its energy. Their construction uses up to three million tonnes of raw materials a year and generates 20% of the soild waste stream. If we want to survive our urban future, there is no option but to build in ways which improve the health of ecosystems. Understanding the concept of ecological sustainability and translating it into practice as sustainable development is a key challenge for