The green roof is an architectural concept based around sustainable development. This type of flat roof, with suitable thermal insulation and a bituminous waterproof membrane, carefully prepared to have a substrate and vegetation across the whole surface, is known either as: Extensive or Intensive

Extensive vegetation
An easy process to implement because the plants only use a small amount of soil (a substrate with a composition that is essentially mineral-based and a thickness of between 6 and 10 centimetres). Naturally, these are species that have little need for water, care and nutrients. They normally grow in arid and uncultivated places and do not need to be pruned or mown.

Intensive vegetation
This is a form of vegetation that is mainly horticultural. It is a multi-functional garden with a lawn and perennials, shrubs and bushes with various uses. It requires a great deal of attention, implementation and care regarding cultivation and upkeep. These roofs have an important ecological impact: they contribute to the well-being of residents and allow wildlife to find habitats where natural equilibrium is restored.