Sustainable buildings, also known as “green” or high-performance buildings, are designed to effectively use energy, water, and other natural resources while providing a safe and efficient indoor environment. These buildings aim to minimize their environmental impact in terms of energy and resource use. One important component of sustainable buildings is green roofs, which can improve the energy performance of a building without the need for additional equipment. Green roofs also have benefits such as improving air quality, contributing to urban ecology, and providing innovative solutions to rainwater-related issues.
Urban heat islands are areas in metropolitan areas that are significantly warmer than the surrounding rural areas, due to the heat generated by human activities such as transportation and building density. Green roofs are designed to address this issue by adding green infrastructure to cities. They can be incorporated into new buildings or adapted to existing buildings, taking up minimal space at ground level. Green roofs are typically categorized as “extensive” or “intensive”. Extensive green roofs are lightweight with a shallow layer of growing substrate, requiring minimal maintenance, while intensive green roofs are heavier with a deeper layer of growing substrate and can support a wider variety of plant types. Intensive green roofs are also more accessible to people due to their ability to support the heavier weight.
The primary construction features of green roofs include water buffering, structural weight, and leakage prevention. Green roofs and the plants on them help retain water in the substrate and drainage layer below, with buffering capacity increasing with more precipitation and decreasing with less precipitation. The excess water can return to the atmosphere through evaporation or be slowly released into the sewage system. It is essential to ensure that the green roof, including the grass or plant layer, does not slip or collapse due to its own weight, especially when wet. The basic anatomy of a green roof includes roof structure, roof cladding, vegetation system, weed control mat, drainage layer for water discharge, filter membrane, substrate layer for nutrition, vegetation layer, and others.
Different types of green roofs are used …
