Living roofs are lifting off
Green roofs, or living roofs, are increasingly being used in new Zealand architecture for their environmental benefits.
auckland Council’s largest living roof on a council-owned building, the Central City Library Tāmaki Pātaka Kōrero, is looking well established after a year of growth. The library roof features more than 2000 low-maintenance, hardy native plants that are flourishing. They were propagated by local iwi Ngāti Whātua Ōrākei, long time advocates of living infrastructure.
“Where in the past gardens and parks did most of the heavy lifting absorbing water, in today’s concrete jungles excess water has nowhere to go,” says Planning, environment and Parks Committee Chair, Councillor richard Hills. “increasing vegetation and mimicking natural systems is one of the ways we can make our city spongier and improve its climate change resilience.”
It is estimated the library living roof system can store between 5‒10 litres of water per square metre before the excess rainfall is either slowly released to the piped stormwater network or taken up by the plants through the evapotranspiration process.
“These surfaces weren’t being used otherwise and it is known living infrastructure has a range of benefits, including the reduction of stormwater runoff, improvement of air quality, protection of roof membranes from solar damage, and increasing biodiversity, which is why some countries are using policy to mandate the installation of living roofs,” adds Councillor Hills.
more living architecture
In Whangārei, the afforested roof of the Hundertwasser Art Centre is another exemplar of living architecture. among its forest of 4000 plants, fruit and indigenous trees, and rare native species grown by Tawapou Coastal natives in northland is one of the rarest plants in the world, Pennantia baylissiana (Kaikomako). Only one plant is left in the wild ‒ on a rocky cliff on the Three Kings Islands. The visionary Austrian artist, architect and ecologist believed architecture should give back to nature what was taken from it by buildings: “what is horizontally under the open sky belongs to nature,” was his principle.
down in Christchurch, a green roof is being installed on the information Centre and Cafe for Otākāro Orchard following a successful crowdfunding campaign. This will complete the final stage of an earthquake recovery project to create New Zealand’s first urban food hub to share food, increase knowledge of growing food and connect people interested in food resilience. Otākāro’s free public food forest is already flourishing on the Cambridge Terrace site, not far from the Thomas edmonds Band rotunda (the man behind the famous cookbook).