Posts Tagged ‘green roofs’

Green, green grass of home: Norwegian turf roofs

26/09/2012

For a moment, let’s leave aside the technical benefits (or otherwise) of green roofs, and just enjoy how they look in the landscape.

In an article for the forthcoming ESI.info Expert Guide on facades, roof finishes and rainwater management, director of the Future Cities project Austin Williams writes:

Green roofs are now lauded for their biodiversity, carbon neutrality, pollution-busting, happiness-inducing, rainfall attenuating, energy-saving goodness. Putting grass on a roof has evolved into a moral agenda that almost brooks no challenge … Specifiers need to be aware that green roofs are not a miracle cure.

This turf roof blends almost seamlessly into its hillside surroundings. Spot the chimney and small skylight on the left!

Needless to say, green roofs alone won’t meet all the challenges involved in creating a built environment that really works… Sometimes it’s good to view them from a purely aesthetic angle.

That is just what I did last August in Norway. On many of our walks during those two weeks, there were turf-roofed cabins round every corner – although because of their camouflage tops, we often did not spot them until we were right up close.

Most of the pictures in this blog post were taken at or around Herdalssetra, an isolated hill-farm that has been in continuous operation for over 300 years. The 30-odd buildings here are generally small, old timber shacks. Their turf roofs are simply a part of that vernacular and a reflection of which materials were most readily to hand at the time. However, we often saw green roofs in new-build housing developments in major cities like Oslo and Trondheim.

This post, then, is intended as a low-tech visual feast and nothing more. I hope it conveys some of the beauty of the Herdalen valley. Look at these pictures and imagine the bleating of goats, the crunching sound of fjord horses grazing in juicy pastures, the smell of sun-warmed juniper and dwarf birch, all to a backdrop rush of snow-melt waterfalls – and you’re half-way there!

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Green covers from Down Under: an Australian designer’s summary of green roofs

05/03/2012

Our ‘Australian Correspondent’, Mark Iscaro of First Angle, is in the process of specifying a green roof for a client’s building. In this guest post, he takes a closer look at the concept, components and benefits of living roofs.

San Francisco Academy of Sciences, by Osbornb on Flickr

“This blog will be focusing on a new Green Building initiative in Australia that is slowly making its way into the mainstream. Currently a growing trend around the world, the idea of having a green roof is gradually catching on. Even one of my own clients has finally given in and allowed me to put a green roof on their new building in Marysville.

So what is a green roof?

A green roof is a partially or completely covered roof containing a growing medium and vegetation. These are positioned over a waterproofing membrane and can include water retention, drainage and irrigation systems. There are two main forms of green roofing available in Australia: intensive and extensive, the difference being as follows:

  1. Intensive roofs (roof gardens) contain over 300mm of plant growth and can include a wide variety of shrubs, grasses, tree species and even kitchen herbs. They are also more akin to a park or garden, with easy access for recreational purposes.
  2. Extensive roofs contain less than 300mm of growing media, and so are generally lighter in weight. They are suitable for harsher growing conditions and require minimal irrigation, using hardy, low-growing plant and ground-cover species. These roofs can handle slopes up to 30°. Extensive roofs are usually only accessed for maintenance.

Commercial green roof installation, by Arlington County on Flickr

What are the benefits of green roofs?
• Reduce heating (by adding mass and thermal resistance value).
• Reduce cooling loads on a building by 50 to 90% (by evaporative cooling), especially if it is glassed in so as to act as a terrarium and passive solar heat reservoir: a concentration of green roofs in an urban area can even reduce the city’s average temperatures during the summer.
• Reduce stormwater run-off.
• Natural habitat creation, promoting biodiversity.
• Filter pollutants and carbon dioxide out of the air, which helps lower rates of diseases like asthma.
• Filter pollutants and heavy metals out of rainwater.
• Help to insulate a building for sound: the soil serves to block lower frequencies and the plants block higher frequencies.
• Increase agricultural space.

So now that you know a bit more about these wonderful creations and the benefits they provide, why not look at one for either your current home or perhaps your next project?

Note: Information was gathered from Wikipedia & Green Roof Technologies.”

Mark is active on Twitter, and details of his projects can be found on the First Angle design and planning website.

For more facts and figures on green roofs in the Southern hemisphere, Green Roofs Australasia is worth a visit. A good variety of extensive, intensive, semi-intensive and brown/biodiverse roofs can also be compared over at ESI.info. If you are looking to plant a facade rather than a roof, have a look at what’s available in terms of living walls and vertical gardens.