Latest news with #LivingRoofMonitoring
RNZ News
30-04-2025
- Science
- RNZ News
Living roof project could provide green shoots for Auckland's concrete jungle
Photo: Supplied / Auckland Council A project to measure the benefits of living roofs in Auckland has shown surprising results that researchers hope take root. The trial led by Auckland University, Ngāti Whātua Ōrākei and local council compared the performance of green rooftops to conventional ones in dealing with the elements. Those working on the Living Roof Monitoring project atop of Auckland's Central Library say the benefits could be wide ranging. One of the most impressive findings has been the influence living roofs could have on stormwater management. University of Auckland professor Asaad Shamseldin, who leads the research with Dr Kilisimasi Latu and Dr Conrad Zorn, said the results have been fascinating. "They show that the living roof can, for a small rain, they could effectively absorb all the rainfall and even during heavy downpours, they could reduce or they could absorb 80 percent of the rainfall," he said. "But that's not the whole story, they do have also other benefits in terms of air quality, and also in terms of mitigating urban heat islands." Photo: Supplied / Auckland Council An urban heat island happens when a city experiences much warmer temperatures than nearby rural areas due to the concentration of buildings and human activity. "So the research we are doing so far shows that during the summer, when it's very hot, the living roof is acting like a natural air conditioner, and when it is very hot, then the green roof will reduce the temperature, anything between 32 to 56 percent, and not only that one, it also delays the peak." "It's providing cooling to the roof and of course if you have a cooler building, it means that if you are using air conditioning and stuff like that, it means that you don't need to use a lot of energy to cool your building. "Also the wind blowing from the sea plays a considerable part in the cooling and also delaying the peak and during the night the wind helps to narrow the gap between the temperature in the living roof and the conventional roof," Shamseldin said. It's all down to the more than 2000 native plants on the Auckland Library roof which were propagated by Ngāti Whātua Ōrākei in their nursery and planted five years ago. "Kaupapa like this green roof are examples of cultural infrastructure, they integrate nature into our cities and allow us to actively elevate the mauri of our taiao," said Etienne Neho of Ngāti Whātua Ōrākei. "It was a way to also showcase to the rest of Tāmaki that having a green roof on your building has so many benefits, more than just bringing back the birds, It helps with the rainfall, It helps with basically the maintenance nightmares that some buildings can face with having a lot of high water on their roofs. "But also it shows that there's a way that we can offset our development in our buildings through having some form of green within our building scapes. "We looked at plants that traditionally would have been found in waterways and would have been found in swamps and in areas where there was a lot of high water. Photo: Supplied / Auckland Council "So we've got our rushes and our reeds in the form of oioi, they're a plant that you'd find quite commonly along the banks of awa and stream, they're water filterers and they're water holders. "They're really soluble to the water, so when it's raining and when, say for example, you have a bit of surface flooding, they'd soak them up and they'd hold that as well as re-releasing it in a filtration system. "It was a choice of what plants not so much looked good, but what plants would be well suited for their purpose up here," he said. Neho, who manages the Ngāti Whātua Pourewa Maara kai, said it was fitting the pilot programme that they were hoping to learn from, was conducted on the roof of a library. The actual design and the layout of the plants is in a whareki format, which is a form of weaving, and the actual design itself is called poutama. "Poutama, to those that know, means growth and ascension, and it's fitting that it's on the library rooftop because as the people grow down below via their book work and via their studies, the plants are growing on top, and they're kind of teaching us as well how they can thrive in this setting. "Despite the odds, on a rooftop in sometimes quite harsh conditions, they can thrive as well, and that's a learning for us as well," he said. The plants have been thriving, with a 90 percent survival rate according to Auckland Council's curator botanic gardens Bec Stanley. "The aim for this roof is that it's self-sustaining, so in the early years of any green infrastructure, you do need to manage them a little bit more while they're establishing. "But through time, it's expected that they become self-sustaining and we're already seeing that here. "We're seeing the plants we've planted, but we're also seeing their progeny, we're seeing their offspring, these plants are flowering, they're seeding, and their seeds are germinating and growing new plants," she said. And where there's native plants, native animals are soon to follow. "We've seen a few insects arriving on the roof and the more flowering that we see, the more pollinators will be attracted to this roof. "So especially I'm interested in the harakeke, the tui, for example, in the inner city, I'm thinking that they will eventually find this roof because harakeke are a really, really enticing food source for them. "We're particularly hoping we get some native insects here to pollinate our native plants, and also some pollinators like birds. "Increasingly we're hoping to get more native animals up onto this roof to live in association with the native plants that we've planted for them, that's the goal," Stanley said.
Scoop
30-04-2025
- Science
- Scoop
Pilot Project Delivers Promising Results For Sustainable Urban Design
Press Release – Auckland Council Advocates for living roofs, those lush, plant-covered patches of green on our city buildings, have long championed these slices of eco-paradise in our urban jungle. Now, thanks to a pioneering project between Auckland Council and the University of Auckland, we have the data to prove their value. The Living Roof Monitoring project was launched to assess how well these verdant rooftops perform compared to conventional ones. After months of careful monitoring, the results highlight their effectiveness as a sustainable urban solution. Stormwater superstars Auckland Council's Senior Healthy Waters Specialist Rachel Devine highlights the global success of integrating nature into urban infrastructure. She explains that planting vegetation on rooftops is one of the ways that cities can effectively absorb rainfall, reduce flooding and mitigate the stormwater network from becoming overwhelmed. 'But now, having the local data to back this up gives us context that is relevant to Auckland's climate and environment,' Ms Devine says. University of Auckland Professor Asaad Shamseldin who leads the research with Dr Kilisimasi Latu and Dr Conrad Zorn, is pleased with the robust dataset collected by the team's PhD students Aung Naing Soe and Sihui Dong, which focuses on assessing the benefits of plants over conventional coverings on rooftops. Their findings show living roofs significantly reduce stormwater runoff, with some substrate types retaining nearly 80 per cent of rainfall, even during heavy downpours. And that almost every drop is retained in light rainfall, demonstrating the excellent absorption potential of these gardens. Chair of the Policy and Planning Committee Councillor Richard Hills says the findings of this research are very promising for roof gardens, helping to prevent flooding and water pollution in built-up urban areas like the inner city. 'This preliminary research indicates that if we could retrofit roof gardens all over Auckland's city centre it would not only enhance our place as a clean green city on the global stage but would also be a viable aid in reducing heat and help prevent or reduce flooding in parts of the city centre. 'It would also make the city look more beautiful for residents in high rise apartments, staying in hotels or working in offices and provide tangible environmental benefits, including providing habitats for native plants and birds. 'Stormwater run-off in the city centre also contributes to the pollution of the Waitematā and the Hauraki Gulf, and these findings point to roof gardens curtailing much of this run-off into our precious oceans and harbours. Nature's air conditioner: cooling our concrete jungles Professor Shamseldin adds it is important to remember living roofs aren't just about stormwater management; they are also very effective at keeping things cool. 'When urban temperatures rise, green roofs act like nature's air conditioners,' says Professor Shamseldin. In Auckland's hottest months, when temperatures can exceed 25°C, the data shows living roofs lower rooftop surface temperatures by an impressive 32 per to 56 per cent. The research even uncovered a surprising ally in urban cooling: the wind. 'During the day, sea breezes help cool green roofs and delay peak temperatures, while at night, city-to-sea winds help reduce the temperature difference between green and conventional rooftops,' explains Associate Professor Shamseldin. This translates to tangible energy savings for buildings and a potential reduction in the Urban Heat Island effect – truly, a breath of fresh air from above. A living legacy: onshore islands The pilot study was inspired by Auckland's Central City Library living roof, a project developed in partnership with Ngāti Whātua Ōrākei that was launched five years ago. Featuring over 2,000 hardy native plants, the roof reflects a shared commitment to enhance urban biodiversity and live in harmony with te taiao (the natural world). 'Kaupapa like this green roof are examples of cultural infrastructure, they integrate nature into our cities and allow us to actively elevate the mauri of our taiao,' says Etienne Neho of Ngāti Whātua Ōrākei. Greener cities, smarter cities: a vision for the future This collaboration already has the potential to influence Auckland's future. By providing policymakers and urban planners with data, the project can inform smarter, greener development decisions that enhance urban environments. 'If we want to create a sustainable, healthy city, one that future generations can enjoy – working with nature is a must,' adds Ms. Devine. 'These results prove what we've long suspected: nature-based solutions can help our journey towards becoming a more sustainable and resilient city.' The research team continues to monitor additional biodiversity benefits, and more updates will follow as the data flourishes. Although urbanisation and climate change present numerous challenges, one thing is certain, working with nature is a positive step towards a healthier urban environment.
