Circular economy refers to preserving the value of existing things, both materials and buildings. Therefore, when possible, it is preferable to renovate buildings to save the added value of existing elements such as the structure. Renovation is particularly relevant in economies with a large number of existing buildings, such as those in Europe. Circular economy includes: new business models, new ownership structures, a different way to live and use buildings, a different way to build and manage water and energy.

Buildings are considered temporary storages of materials that can be reused at the end of life or end of use. Extending the lifetime of materials, the application of renewable bio-materials and above all the reuse of materials, products and building elements are fundamental principles for new constructions and renovations. Cost structures will change to favor circular materials over non-circular materials. Buildings will become more modular to allow for expansion, to facilitate easy modification for different uses, and to allow easy deconstruction and reuse of products and materials.