A building that is sustainable must by nature be constructed using locally sustainable materials, i.e. materials that can be used without any adverse effect on the environment, and which are produced locally, reducing the need to travel. There are key criteria that can be used to judge whether a material is sustainable or not, namely:
- to what extent will the materials used in this building cause damage to the environment?
- to what extent will a building material contribute to the maintenance of the environment in years to come?
- to what extent is the material used locally replenishable?