A traditional linear economy involves sourcing new raw material, making it into products, using those products, and then treating the redundant products as waste. A feature of the circular economy as applied to buildings is the idea of them being inherently flexible and reusable, not just as a whole but as a collection of materials. For designers, contractors and the supply chain, education is also necessary to bring about increased understanding of recycling and the circular economy concept. Recycling can occur at any scale, from reuse of entire structures and buildings through reuse of systems to recycling individual components or materials. Recycling of basic materials is, however, much more widespread, occurring in a large range of construction materials such as steel, aluminium, concrete and so on. A large proportion already goes to recycling depots for reuse, although often to be used at a lower level.