There's green gold across our harsh landscapes
by Geoff Wilson. All Photos Courtesy Dr. Raelene Mibus, unless otherwise stated

Australia's built-environment industry has the opportunity to develop global rooftop service businesses based on our hardy coastal and inland plants.

Hardy native Karkalla

But it will require some quick local footwork. Europeans are at least 20 years ahead in the environment-enhancing, cost saving green roof business, and the North Americans at least five years ahead.

Northern hemisphere green roof entrepreneurs will probably see the opportunities of our plethora of hardy plants before we do, especially as more of them sniff out green roof business opportunities in Australia and New Zealand.

Expect it to happen from next February, when a two-day event, Green Roofs for Australian Cities will be held at the Brisbane Technology Park in Eight-Mile Plains, Queensland. The event will have a pictorial display of around 100 of the world's best green roofs on commercial buildings and on suburban homes.

Green roofs is the new business expansion opportunity now in prospect for Australian architects, urban planners, developers, builders, horticulturalists and building owners.
The good news is that their colleagues overseas have developed green roof technology to a high level of efficiency and reasonable cost.  Even better news is that many overseas green roof experts will be looking for Australian and New Zealand business connections from now on.They will also be interested in Australian native plants for the world's green roofs.

The advance guard of the northern hemisphere green roof industry is already operating in Australia, and is sniffing out opportunities in our native plants.

Why the sudden interest?
Overseas green roof technology advances in 14 countries of Europe and North America, mean that green roofs of various designs are now considered to be important community corporate and individual responses to the scary prospect of climate change. They are searching for the hardiest greenery for less costly rooftop maintenance, and the most attractive visual landscape. Australian native plants can provide both.

Perhaps just as important is the now well-proven selling pitch that green roofs save money : big lumps of it.

Green roof benefits include:

Thermal insulation  Reduces fossil fuel energy use in heating and cooling of buildings.

Noise insulation  This is particularly important against transport noises, especially trains, trams, buses, trucks and aircraft.  Tests have shown that a 12cm green roof pad will reduce noise by 40 decibels.

Slower runoff of rainfall at peak times Enables drainage infrastructure to cope without massive and costly upgrades. Climate change may bring many more peak loads.

Reduction of ambient temperatures in cities   Caused by the heat island effect of buildings and roads, the reduction sometimes is five to 10 degrees Celsius above rural temperatures close by.  The City of Toronto estimates that a mere 8% of green roofed buildings will reduce its heat island effect by up to 2 degrees C (see Side Story).

Air cleaning Green roofs trap harmful particulates and dusts.

Water cleaning When micro-organisms in a green roof 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.

Longer roof life and lower roof maintenance costs  Studies have shows that a green roof can protect the underlying structure so that it will last around 40 years instead of 10 to 20 years.

Visual beauty  A green roof looks great, and has a calming effect that reduces urban stresses on people and enables hospitals to release patients up to two days earlier in some cases.  Green roofs also provide urban workers with more pleasant, restful surroundings and a more pleasant place to enjoy lunch.

Habitat creation for small song-birds, butterflies and bees This has been found to be significant in some suburban green roof developments overseas.

Food from the roof  This is a business opportunity for many as technologies such as hydroponics, aquaculture and aquaponics are being placed on commercial rooftops close to where produce is consumed . 

Extra revenues for building owners  Renting for food from the roof, or providing a more valuable office or work environment for tenants is possible.

More valuable buildings  Real estate valuers are predicting that retrofit green roofed buildings will improve in value by 5% to 10% at least.

And that's another benefit we will experience -- greater urban colour from green roofs.  It could change forever the drab look of parts of our cities, especially during winter.  In Brisbane, green roofs using native flowering plants could provide a riot of delightful, restful colours across our CBD and our sun-dried suburbia.  Big payoffs will be reduced fossil fuel energy use, and more efficient water use : two points that will resonate politically at municipal, state and federal government political levels..

So let's take a good look at these exciting new uses and business prospects for our hardy coastal and inland plants before the Europeans and North Americans swipe our best.

It is in our national interest as an exporting nation, and in the global interest as a country blessed with a native plant gene pool of extraordinary potential.  Green roof plant material from Australia can help further develop the ability of the worlds cities to defeat runaway climate change effects before it is too late.

10 Oct 2006: Toronto study shows big cost savings
A study released early this year in Toronto, Canada, has shown that green roof technology can reap huge cost savings for building owners and the community.