Compared to extensive green roofs, intensive green roofs are heavier greening systems with a thicker growing medium and more varied vegetation types including perennials, shrubs and small trees. Depending on design, intensive green roofs provide benefits like storm water storage, reduction of air and water pollution, reduction of localized air temperature and biodiversity enhancement. They are commonly found on residential buildings, hotels and parking structures and are often multifunctional areas that can be used for many activities including gardening, relaxing and socializing.