Urban Greenery Benefits We Now Need, Include These 16

20 January 2010

Geoff Wilson,
Secretary, Rotary Club of Carindale
Director, World Green Infrastructure Network
President, Green Infrastructure Network Australia Inc.
Email: wilson.geoff@optusnet.com.au
Website: http://www.gina.org.au/

• Thermal insulation – reducing fossil fuel energy use in heating and cooling of buildings. Green roofs can save at least 7% to 8% of heating or cooling costs of buildings in thermal insulation. Green wall advantages are similar, and are being documented. Extra thermal insulation comes from a combination of standard insulation plus the depth of 10cm to 20cm of greenery and substrate.
• Storm-water management: lower runoff of rainfall at peak times – enabling drainage infrastructure to cope without massive and costly upgrades. Climate change may bring many more rainfall peak loads which challenge existing storm-water drainage works. Municipal governments are starting to realise that much-reduced peaks of rain-water runoff (50% to 90% reductions are possible) from urban roofs mans massive cost savings of storm-water maintenance.
• Reduction of ambient temperatures in cities, caused by the “heat island effect” of buildings and roads. Sometimes this effect can be five to 10 degrees Celsius above rural temperatures close by. The City of Toronto in Canada estimates that a mere 8% of green roofed buildings can reduce its city heat island effect by up to 2 degrees Celsius. Perhaps the biggest cost-reduction benefit is to owners of air conditioners on rooftops or sunlit walls – reducing the input air temperate by 10 to 20 degrees C – saving massive over-use of energy in air conditioning. Reduced lightning in cities is also reported benefit from lower urban air temperatures.
• Enhanced solar electricity collection. In Germany, where about half the world’s solar power collectors feed electricity into the local grid, green roofs are lowering solar cell temperatures to produce 2% to 12% more electrical power. In Australia’s hotter conditions the solar power advantage of green roof cooling is expected to be from 10% to 25%. GINA Inc is about to help fund Brisbane-based Brian Chua, to demonstrate stresses on people and enables hospitals to release patients from half a day to two days earlier from intensive care wards. Green roofs and green walls also provide urban workers with more pleasant, restful surroundings that increases productivity and reduces staff turnover and absenteeism.
• Habitat creation for small song-birds, butterflies and bees. This has been found to be significant in some overseas suburban green roof developments. Ford Motor Co in Dearborn, Michigan, United States, has a bee farm on its 10.4 acre green roof. Other green roof projects are aimed at providing habitat for migratory birds. It is a developing field of great interest to members of GINA inc.
• Fire resistance. A study in Berlin found that fire resistance is particularly the case with succulent plants. It is also relevant to ‘earth roofs” for Australian farmers in fire-prone areas. In many parts of Australia, South Africa, the French Riviera and California, green roofs in urban and rural areas can save lives and property losses from fire.
• Electromagnetic insulation. Electromagnetic radiation is said to be reduced by 99.4% with a 10cm substrate depth of green roof.
• Food from the roof. This is a business opportunity for many, as technologies such as hydroponics, aquaculture, aquaponics, vermiculture and insect culture, are set on commercial rooftops, or home roofs, close to where produce is consumed. Importantly, they will recycle food nutrients within clean organic matter collected in cities. This will reduce methane emissions from landfill.
• Extra revenues for building owners renting for food from the roof, or providing an improved office or work environment for tenants, who are willing to pay more for superior office environments that increase staff productivity. Owners of green roofed and walled building find their rental properties easier to market, and productive of higher rentals, plus better tenants.
• More valuable buildings. Real estate valuers are predicting that retrofit green roofed buildings will improve in capital value by at least 5% to 10%. In many municipalities green roofs and walls allow extra ground floor car park spaces to be approved. Some municipal authorities now offer “fast tracking” this great benefit to solar electricity collection. The first project will be at the Green Infrastructure Education Shed being developed at Carindale, by the Rotary Club of Carindale. Other “Green Sheds” in and around Brisbane are planned.
• Air cleaning effects. Green roofs and green walls trap and ameliorate harmful particulates and dusts. Microbial action within the green roofs and walls may be enhanced with probiotics that reduce, to harmless products, air-borne carcinogens on particulates or in dusts. Air cleaning can also reduce the incidence of lightning strikes in cities. Gina Inc has members providing services for internal and external greenery in this important field.
• Water cleaning effects. When micro-organisms in a green roof or green wall chew up harmful airborne particles, the water then harvested from the green roof is much purer than street or rooftop runoff. A green roof can also be used to renovate “grey water” from homes and businesses. New technology is solar-powered air moisture harvesting is expected to become a major alternative to the rising cost of municipal waters – perhaps avoiding the need for further dams and expensive reticulation.
• Longer roof life and lower roof maintenance costs. A green roof can protect the underlying structure so that it will last around 40 years instead of 10 to 20 years. This is a common experience in countries where adverse climate effects roof life. Green wall shade can reduce the effect of sunlight on wall paint, extending the time between paintings.
• Noise insulation against transport noises – especially trains, trams, buses, trucks and aircraft. A 12cm deep green roof pad will reduce noise by 40 decibels. The Netherlands’ Schiphol Airport has been built with green roof technology for this purpose.
• Visual beauty and human health: A green roof has a calming effect that reduces urban of building designs that have green roofs – thus reducing the original cost of the building and adding to its value.
• Savings for governments. With rapid urbanisation around the world, and rapid onset of climate change problems, government leadership on green roofs is vital. The City of Toronto estimates that 8% green roofs in Toronto made direct energy savings of C$12 million a year in buildings from reduced cooling demand in summer. Indirect savings included reduced peak load energy demand of C$80 million a year. Also, it meant reduction of storm-water flows by 12 million cubic metres a year, so that existing drainage infrastructure can cope, and sewage overflow events were less frequent. Toronto’s savings from 8% green roof cover were estimated to be C$79 million a year from reduced capital costs for storm-water management, erosion control and sewer overflows.

Urban greenery technology is now Australia’s most important business opportunity!

These 16 good benefits of greenery in urban infrastructure will be discussed at lecture courses of the Green Infrastructure Educational Shed project initiated in Brisbane, Queensland, Australia, by the Rotary Club of Carindale. The first shed’s expected completion is in mid 2010.

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