Green roofs come in all kinds, shapes and sizes. Intensive green roofs can mean full-fledged gardens or parks with shrubs and trees on top of buildings, which require a very strong roof structure. An extensive green roof or sedum roof is a type of green roof system that is lightweight, low-maintenance and sustainable. These kinds of green roofs broadly consist of three layers: (1) a vegetation layer, also known as the sedum blanket, (2) a substrate layer, and (3) a drainage layer. The system structure is 11 to 16 cm thick. The application of a lightweight extensive green roof is not only possible on newbuilds, but also very common on existing roofs. Their installation creates an instantly green environment and provides many other benefits.
Below, we’ll explain why exactly green roofs are such great solutions for Australian cities’ climate and urban liveability!
Are you wondering what the differences are between extensive and intensive green roofs? Read more on this topic in our article here.
Benefits of green roofs in Australian cities
Green buildings help reduce the urban heat island effect
Urban heat islands – city areas with little greenery and water and many hard, sealed surfaces instead – create higher temperatures in cities during already hot summer days and heatwaves. For example, “temperatures in western Sydney, which has less green cover, are sometimes 10 °C higher than in eastern Sydney” (source: NSW Government). Extensive green roofs, which include a layer of lightweight soil and drought-tolerant vegetation, can help regulate temperatures by evapotranspiration of water and by reflecting more solar radiation than dark roofs would. A large surface area of green roofs not only helps to cool the outside of buildings and thus the city environment, but also reduces the need for excessive air conditioning inside, thereby lowering energy consumption.
Vegetated roofs are a natural tool for stormwater management
While water scarcity is becoming a bigger problem, periods of intense rainfall like downpours are also becoming more common in Australia. This leads to more stormwater runoff issues. Vegetated roofs act as natural sponges, absorbing rainwater and reducing immediate runoff. The plants and soil on green roofs perform evapotranspiration as well as retaining and filtering rainwater, allowing it to be released into the sewage system and onto the streets more slowly. This alleviates the pressure on existing infrastructure and decreases the chances of flooding.
they Create stepping stones for urban wildlife
Many urban areas in Australia experience habitat loss due to large-scale development. Green roofs provide an opportunity to reintroduce vegetation into our neighbourhoods, promoting biodiversity and creating natural stepping stones for insects, birds, and other wildlife.
plants help to improve Air quality
Urban areas in Australia often suffer from air pollution, which can have detrimental effects on public health. Extensive green roofs act as natural air filters, capturing pollutants and particulate matter from the atmosphere. The vegetation on these roofs absorbs carbon dioxide and releases oxygen, helping to improve air quality and create a healthier urban environment.
functional roofs increase aesthetics and community well-being
Green roofs offer aesthetic benefits by transforming concrete-dominated urban landscapes into lush, green spaces. They provide opportunities for recreation, relaxation, and community engagement. Accessible green roofs can serve as communal gathering areas, rooftop gardens, or even urban farms, offering numerous social, psychological and health benefits to residents.
green infrastructure is part of sustainable urban development
Embracing extensive green roofs aligns with the principles of sustainable urban development. By integrating green infrastructure into the built environment, cities can become more resilient, environmentally friendly, and socially inclusive. Green roofs contribute to the overall sustainability goals of reducing energy consumption, mitigating climate change impacts, and enhancing the quality of life for residents.
vegetated roofs are suitable for almost every existing roof structure
Because of their straightforward installation and relatively low weight, our green roof systems are suitable for many types of (existing) buildings. However, it is still essential to consider the structural capacity of your building. Get in touch with us if you have any questions. Our experts are happy to help!