The Demise of the Green Roof
PHASE 1: Cost-effective building performance (more from less) This is an Icelandic turf house. They’ve been around for say, 1,000 years – about since the time of the Vikings, let’s say. The turf provided better insulation than wood or stone which were difficult to get enough of anyway.
Technically, I suppose, we’ll have to include dugout buildings and cut-and cover buildings such as these since they do make use of the insulating properties of soil and vegetation.
If we do that, we’ll also have to include dwellings such as these yaodong in Northern China. This image is from Bernard Rudofsky’s Architecture Without Architects: A Short Introduction to Non-Pedigreed Architecture and, thanks to Pinterest, is famous once again. (The principles of yaodong date from 200BC btw.)
These munitions bunkers are part of the Suomenlinna (Castle of Finland) which is a sea fortress built in 1748 before the invention of reinforced concrete. The bunkers are covered with a layer of earth to dissipate the force should the ammunition explode. The grass isn’t there to look pretty but to keep the earth in place.
PHASE 2: A pretend garden, but better than nothing. Ahh, LC’s 1930 De Beistegui apartment garden is always a laugh. It looks like a green roof, non?
Green roofs of this type are really just gardens for biophilic or other enjoyment in places where otherwise there would be nothing.
PHASE 3: Sundry enviromental benefits Even if a rooftop garden has no direct benefit for humans apart from prettifying some open space, birds and bees and other insects can still do with additional habitat. Here’s one designed for bugs.
In addition, soil required to grow plants may slow down the runoff of rain. The presence of soil and vegetation instead of concrete will lessen the heat island effect. Here’s one doing all those things on top of Chicago City Hall.
PHASE 4: Symbol of global environmental benefit These next three buildings are all feature domed structures partially covered with grass. The first is a greenhouse so it must be good for the planet.
This next one is Renzo Piano’s California Academy of Sciences.
And this is a biogas production plant which, as symbols go, I far prefer to the greenhouse. It’s doing something more useful than simply coercing plants to grow in locations they’re not meant to.
Ultimately however, it’s cosmetics, even though I don’t think producing biogas is anything to be ashamed of.
Here’s a volcano shaped building – the Volcano Buono – with its shopping mall, outdoor theater, restaurants and a hotel all covered in green roof. Yes, it’s probably better to have this roof than to have a concrete one as far as heat island effect is concerned. Cheers Renzo! Now what about that car park?
PHASE 5: Symbol of general social decline Further down the line, we have green roofs like this. This particular one has done a lot to hasten the demise of green roofs generally. For all the press it’s garnered, there’s no mention of anything this green roof having any agenda other than inspiring dubious claims to fostering creativity.
If art school was in our future we might opt to study under, or on top of, the amazing green roof at the School of Art, Design and Media at Nanyang Technological University in Singapore, designed by CPG consultants. This 5 story facility sweeps a wooded corner of the campus with an organic, vegetated form that blends landscape and structure, nature and high-tech and symbolizes the creativity it houses. Read more: A Swirling Green Roof Tops Nanyang Art School in Singapore | Inhabitat – Sustainable Design Innovation, Eco Architecture, Green Building.
PHASE 6: What can we expect next?
Further Resources: EPA Reducing Urban Heat Islands: Compendium of Strategies: Green Roofs www.epa.gov GreenSave Calculator. Compare the cost of green roofing with conventional roofing systems. www.greenroofs.org