Green Roofs in Urbanised Areas
What is a green roof?
A green roof, also known as a living roof or vegetated roof, is a roof of a building that is partially or completely covered with vegetation and soil or a substrate, over a waterproofing membrane. Instead of being a conventional roof with shingles, tiles, or metal, a green roof supports the growth of plants, creating a living ecosystem on top of a structure. Green roofs offer a range of environmental, economic, and social benefits. They are often employed in urban areas to counteract some of the negative impacts of urbanisation, improve sustainability, and create more liveable and environmentally friendly cities. As urban areas continue to grow and available green space decreases, green roofs provide a means to reintroduce nature into cities without taking up valuable ground space, maximising the use of existing infrastructure.
There are typically two main types of green roofs:
Extensive Green Roofs. Extensive green roofs are characterised by shallow planting depths (usually 5 to 15cm) and are designed for low-maintenance, drought-tolerant plants like sedums, grasses, and other hardy ground covers. These roofs are lightweight and can be suitable for retrofitting existing buildings.
Intensive Green Roofs. Intensive green roofs have deeper planting beds (15cm or more) and can support a wider variety of plant species, including trees and shrubs. They are more like traditional gardens and can accommodate a range of landscaping features, such as pathways, seating areas, and even small ponds or streams. Intensive green roofs require more maintenance, irrigation, and structural support due to their weight, making them suitable for larger, purpose-built structures.
What are the benefits of living roofs?
It's important to note that the specific benefits can vary depending on factors like the type of vegetation, climate, building design, and maintenance practices. While green roofs offer numerous advantages, they also require careful planning, installation, and maintenance to realise their full potential. With that being said there are many fantastic benefits of living roofs. Here are some of the key advantages:
Improved Stormwater Management: Green roofs absorb and retain rainwater, reducing runoff and the risk of flooding. They can also filter pollutants from the rainwater, improving water quality.
Energy Efficiency: Green roofs can provide insulation and reduce heat transfer, which can lead to energy savings. They help keep buildings cooler in the summer and warmer in the winter, reducing the need for heating and cooling. They can also help reduce heat stress in urban areas by cooling the surrounding environment and improving overall comfort for residents and workers
Urban Heat Island Mitigation: In urban areas, green roofs can mitigate the heat island effect by reducing the absorption and re-emission of heat from buildings and pavements. This can help lower ambient temperatures in cities.
Enhanced Biodiversity: Green roofs provide habitat and food sources for birds, insects, and other wildlife, promoting urban biodiversity.
Noise Reduction: Green roofs can help dampen sound, making buildings quieter, which is especially valuable in densely populated urban areas.
Improved aesthetics: Green roofs can enhance the aesthetics of an area. Flat roofs can often be seen from first floor windows and a living roof is a much nicer view than a standard flat roof material.
But are green roofs just a passing phase?
Green roofs are not just a passing fad! They are a sustainable building practice with a history dating back thousands of years and a growing presence in modern urban planning and architecture. Green roofs have been used in various forms for centuries, with examples dating back to ancient civilisations like the Mesopotamians and the Vikings. This historical presence suggests that green roofs have inherent benefits that have stood the test of time.
While they have gained more attention and popularity in recent years, their benefits and long-term sustainability make them a valuable and enduring feature in the built environment. As concerns about climate change, urban heat islands, and the need for sustainable development have grown, green roofs have become an attractive solution for mitigating these issues. Their environmental benefits make them a valuable tool for addressing contemporary challenges.
Ongoing research and technological advancements have led to improved green roof systems, making them more efficient and cost-effective. This, in turn, encourages their continued use. The growing awareness of environmental issues and sustainable practices has led to increased interest in green building techniques. This public awareness is likely to continue driving their adoption, meaning we will likely see a lot more living roofs in the years to come.
Even if you have a smaller residential project, a living roof can still be a viable option for you. Talk to any of our team today to see what your options are.