Research Project on the Rooftop of ANZ House in Adelaide, South Australia

Current research

A current research project by Fifth Creek Studio seeks to quantify some of the benefits of green roofs. The 12 month project is funded jointly by the South Australian Government's Building Innovation Fund and Aspen Developments, with the University of Adelaide and University of South Australia engaged on various aspects of the project. The project involves monitoring thermal performance, water quality and useage, and plant performance characteristics of extensive and intensive green roof beds on the 22nd level rooftop of ANZ House in Adelaide, installed with the permission of ANZ House owners Colonial First State. The incorporation of a trafficable grating over part of the beds is being assessed for potential creation of beneficial micro climates. The trial period is yet to be completed, however, some preliminary findings are emerging.

Thermal performance is being monitored with sensors throughout the substrate profile as well as at the leaf surface and above the plants for ambient air temperatures. This is being compared to a control sensor on the existing concrete roof. This control surface experienced temperatures up to 50oC during summer, whereas the temperatures below the green roofs were down to as low as 26oC at the same time. This data will be used to develop an insulation value, or possibly an R-Value, for various green roof systems suitable for Adelaide's hot, dry climate.

It is important to realise that lowering roof temperatures with green roofs has many beneficial aspects beside the obvious insulation benefit. The building roof components remain at a constant temperature, therefore there is less movement and stress, especially on joints, and given the changing climate with higher temperatures this will be an important consideration in the future.

The development of an extensive green roof system with a trafficable mesh layer above the plants is showing great potential for insulation and plant performance in Adelaide's climate.  This will lead to a lightweight, economic system that can be incorporated into the building services plant area on top of buildings to reduce running costs of the building and its CO2 footprint.

Future growth

Green roofs are important for cities now and in the future, as they create new biomass within the built environment, and also provide new open space as a counterpoint to urban density. A 3D open space system can be created where green roofs are linked to existing ground level parks and open space to provide multi-layered connections between people and the natural environment. Green roofs, as part of a living architecture, can play a vital role in mitigating the effects of a changing climate and other intensities of our city environments.

Read whole report at: http://www.bpn.com.au/features/bpn-reports/roofing-green-roofs-keep-on-g...