Green Roofs and Walls
A couple of articles this week have reawakened my interest in the value of green roofs and walls in the story of energy and water efficiency. The first highlights the increased popularity of rooftop gardens and green walls in the CBDs of Sydney and Melbourne.
Green roofs date back thousands of years to Viking turf roofs in Scandinavia and the ‘hanging’ gardens of Babylon. Current day green roofs and walls help improve the energy performance of buildings while making them more comfortable and enjoyable to use.
Green roofs can be built on a flat or pitched surface and may be as simple as a thin layer of turf or ground cover plants. More intensive deep soil green roofs can support a variety of vegetation including small trees. The benefits listed in Australia’s Your Home Technical Manual are:
- Longer roof lifespan.
- Improved sound insulation.
- Reduced heating and cooling requirements.
- Reduced stormwater run-off.
- Trapping of gaseous and particulant pollutants.
- Alleviation of urban heat islands.
- Increased biodiversity.
You can find more information on green roofs at Green Roof Australasia.
The second article shows the ingenuity of a group of mixed businesses undertaking vertical farming in Chicago with closed loop systems aiming for ‘net zero’ energy use. It’s ambitious, experimental and exciting to see how they make it work.
Green wall or vertical gardens can be inside or outside of a building. These living walls can also incorporate ponds with fish at the base and a water circulating system that self sustains the garden and keeps the pond clean.
Green wall systems can be as simple as layers of pots on shelving to complex vertical layers of growing medium in specially designed fabrics and containers held up with purpose built structures. Green walls can be made free standing or attached to an existing wall.
Green walls provide similar benefits as green roofs. When contained inside a building they provide additional benefits, including:
- Humidify and oxygenate the air
- Act as filters, trapping dust and absorbing pollutants like formaldehyde.
Vertical gardens are a great solution to growing your own kitchen garden in confined areas. My garden space is now restricted to a large south facing deck with limited direct sunlight and a narrow north facing verandah. A bit of vertical gardening in the right sunny spots will provide ample growing area for my new kitchen garden.
- Marta Lett
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