Home | Contact | Register | Login
Find eco products and services
View eco friendly homes or list your own eco house
Information on sustainable living
Community chat
Buy eco products

Search Eco Articles


 (Optional)

Category


Location

Follow CarlinArcher on Twitter

'Green roofs' - An eco friendly covering

Sunday, September 06, 2009
Photos from Greenroofs.co.nz

There's a lot to love about cities. The activity, the vibrancy, the culture. What's usually missing, though, is nature. This lack is often what drives people to "downsize" and shift into the country.

The concrete jungle, aside from an aesthetic lack of greenery, has many negative environmental impacts. The large built-up area absorbs the sun's energy and re-radiates it, causing the urban "heat island" effect. Hard, non-porous surface areas cause run-off when it rains (stormwater), which collects pollution residues, ending up as contaminated water in our drains.

The lack of continuous natural areas disrupts species populations and discourages biodiversity. And finally there's the large amount of "wasted" space on all those building rooftops.

What if a city could support natural ecosystems? What if it could blend into the rural surrounds, manage some of its own byproducts, clean its own air and even produce its own food? Such a city would use green roofs.

Relatively new in New Zealand, green roofs, or living roofs, were first used several centuries ago in Europe to provide insulation, and are now designed to provide a "natural landscape" in an urban setting. They can range from native, low maintenance landscapes (extensive gardens), to a complete recreational green space, or even an urban farm (intensive gardens).
The advantages of green roofs are numerous. Which ones benefit a city most, Landcare Research says, is dependent on location. In heavily urbanised areas like Tokyo or China, green roofs dramatically minimise the heat island effect, keep buildings cooler and improve air quality. In New Zealand, they are most beneficial for stormwater management, and in London green roofs are used to increase biodiversity.

An organisation called Green Roofs for Healthy Cities believes that the psychological benefits of green roofs are worth a mention too. Studies have shown that people living in high-density developments are known to be less susceptible to illness if they have a balcony or terrace garden. In fact, one study involving patients in the same hospital, recovering from the same operation, found that the patients with a landscaped view had shorter post-operative stays, took fewer painkillers and had fewer negative evaluation comments from the nurses.
Green roofs can also be highly productive. A project in Brooklyn, New York, has reclaimed a large warehouse rooftop, turning it into a thriving urban farm. It's a 6000sq ft (1828sq m) garden producing a range of vegetables which are sold to neighbouring restaurants. Locals drop off their kitchen scraps, grab a spade and get involved. We have a few green roofs to be proud of too, including those at Auckland University, Waitakere City Council, Conservation House in Wellington, and the Sir Edmund Hillary Alpine Centre in Mt Cook, as well as a sprinkling of residential properties.

Perhaps, instead of escaping from the city to the country to find a more wholesome lifestyle, the smart answer is to move the country to the city.
Article by Denise Bester
Environmental writer
 
 

Your comments:

by Anonymous 7 Sep 09, 4 replies : Last Post Sort by:
If you would like to receive email alerts when a reply is posted to this forum thread check this check box

Author Post
Anonymous
3350 posts
Green roofs 
Posted 7 Sep 09 10:23 AM
Wouldnt last long in Wellington, blow to bits in a week.
Anonymous
3350 posts
Re: Green roofs 
Posted 7 Sep 09 5:31 PM
You would be surprised..we know of some in Wellington already plus more are planned in the near future. They are pretty robust and if installed correctly can stand up to pretty much anything that Mother Nature cares to throw at them.
Anonymous
3350 posts
Re: Green roofs 
Posted 11 Nov 09 3:09 AM
A green roof doesn't mean having to do without solar panels. Research suggests that the solar arrays can provide useful shade for plants on the roof, while the cooling effect of the roof can help the photovoltaic system to work better.

Jasper
SolarUK
Anonymous
3350 posts
Re: Green roofs 
Posted 11 Nov 09 10:05 PM
Ergon is trialing a solar PV scheme in Townsville - they have measured a 6 deg C reduction in temperature below a solar panel as compared to the roof without panel coverage: the panels not only reduce the cooling load for the building, but generates electricity to supply the power to run, say, heat pump air conditioners.

Cheers
canbyte
2 posts
Re: Green roofs 
Posted 21 Nov 09 1:26 PM
Lots of hype, lots of subsidy money going to excited designers in this space. Benefits are overstated, usually based on overly expensive engineered projects. What we need is interest in humble projects, done at low cost by ordinary people. Then it may make sense but will not look as sexy as the above photo. Our roof supplies our family's carrot, tomato, leek, strawberry, bean and chive needs and is great fun but will not cool downtown one measurable iota.
 

5 results found