Green facades and living walls use plants to cover building walls. They can be incorporated into the design of new buildings or retro-fitted to existing buildings to limit heat gain by walls, cool internal temperatures and reduce carbon emissions associated with air-conditioning. Transpiring leaves may also cool the immediate environment around the wall or facade.
In addition to cooling, green facades and living walls may offer a number of other benefits, such as capturing rainfall and slowing its entry into the stormwater system, intercepting airborne gaseous and particulate pollutants, attenuating noise, and creating habitats for birds, insects and other wildlife. Last but not least, cities become more ‘liveable’ when plants are integrated successfully into the built environment.
Green or ‘living’ walls systems include capillary or landscape felts fed by hydroponics, irrigated modular panels containing a lightweight growth medium, and stone or cement walls designed to accommodate or support plant growth. Plants grow directly into these wall-mounted or integrated systems, often producing highly aesthetic results.
Climbing plants used on green facades are either containerised or rooted in soil at ground level. Self-clinging climbers adhere to the building exterior by adventitious roots or self-adhesive pads. More recently, modular trellises, stainless steel cables, or stainless steel/HDPE mesh have been developed to support climbing plant growth. In addition to a plant canopy of twining and/or tendril-bearing climbing plants, these ‘double-skin’ green facades create an insulating layer of air between the foliage and building wall.
Although green facades and living walls are increasingly being adopted in new multi-storey building designs, few working examples have been successfully established south-eastern Australia and their benefits are largely untested.
At Burnley, we’re bringing together researchers from plant ecology, horticulture, soil science, energy engineering and sustainable architecture to develop an integrative approach to quantifying the potential cooling offered by green facades. Our ‘Great Wall of Burnley’ is an experimental facility instrumented to enable researchers to monitor microclimatic changes in incident solar radiation, air temperature and wind speed as the plant canopy increases in extent and density.
The results of this research will
- provide ‘proof of concept’ to architects, landscape architects, engineers, building developers and policy-makers
- enable evidenced-based specification of green facades (for example, R-values equivalent to traditional thermal insulation materials)
- pinpoint the plant characteristics at leaf, stem and whole plant levels that contribute to green façade cooling and
- identify climbing plant species for green facades in ‘difficult’ urban sites in southern Australia.
RHD student Pei-Wen Chung research work aims to improve the water use efficiency and to lower the costs of green façades without reducing the cooling effect. Her work will include three major experiments including:
1.Reducing the potable water supply for irrigation;
2.Using grey water for irrigation;
3.Different volumes of growing media will be applied to grow plants.
Bookmark this page to follow the development of our research in this area.