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Green Walls for Greener Cities

Contact with nature is not just an amenity: it's important for well-being. Green walls liven up urban spaces while improving building performance.

This green wall covers the exterior of Whole Foods in Vancouver, BC.

I live in Vermont, where agriculture is an integral part of our culture. I drive past the farms as the seasons change and see when the corn is high or when too much rain has made plowing impossible. And the family sees the results at the local farmer's market. Whenever I visit urban areas, I inevitably end up at the local park or waterfront for my early-morning runs.
I value this connection with the natural world--or biophilia--and maybe it's more than just a lifestyle choice. Biophilia has been shown to have tangible benefits, including reduced stress, improved productivity, and faster healing, to name a few, but integrating greenery among limited--and expensive--urban real estate is no easy task. Maybe the answer is to think vertically.

What is a green wall?

Exterior green walls, sometimes referred to as living walls, green facades, eco-walls, and a variety of other names, use frames mounted to exterior walls to support vegetation growth. Their greenery helps

  • break up the urban landscape of concrete, glass, and steel;
  • improve the thermal performance of a building by creating shade and an air space between the plants and the building;
  • absorb carbon dioxide;
  • mitigate stormwater runoff;
  • and reduce heat and noise.

And since thermal performance and energy-saving design are not visible to the public, green walls are one way for building owners to advertise their green credentials.

GSky exterior Pro Wall System

But green walls have to be well designed and maintained or else you can end up with mold, moisture damage, or dead plants. GSky's exterior Pro Wall System reduces these risks using a stainless steel frame and panels that incorporate a structural growth medium. The plants are pre-grown to design specifications, monitored for temperature and moisture, and watered automatically using a drip irrigation system.
Designing the wall is no easy task. It begins with careful assessment of the site, water and drainage consideration, seismic and wind loads, and power and placement of the irrigation system. Local plants are then selected and pre-grown in a nursery before the panels are installed along with the frame, irrigation, and monitoring system.

GSky's Pro Wall green wall can integrate different plants to create distinctive patterns.

The monitoring system is automated, setting off alerts if there is a problem with the irrigation, and can be paired with GSky's maintenance program. These green walls do not have to be a single shade of green, either. Using different plant species, you can create designs within the greenery.

More basic green walls

GSky also offers its Basic Wall Container System, which contains a trellis and integrated containers to support vine growth. The containers are three feet and five feet high, and the vines can be either pre-grown or allowed to grow naturally, which could take up to two years.
You can't get plant designs with these systems. They are meant for large exterior walls, and can even include a catwalk behind the façade of plants for easier maintenance on high walls. Like the Pro Wall System, they come with an irrigation and monitoring system.

Keeping the "green" in "green wall"

Providing the benefits of biophilia using a green wall only works if the plants are actually green. GSky ensures its systems perform with warranties of ten years on the planters, five years on the irrigation system, and a "100% Plant Health Guarantee" when paired with the maintenance contract.
We've updated our green walls section in GreenSpec and added a couple of new products. Check them out. While green walls might not be ideal for every building or climate, the more greenery we can add to urban environments, the more I'll feel at home while visiting.
 

 

Posted by Brent Ehrlich on January 25, 2012

Comments

Appending living things to urban buildings is about as biophilic as putting wild animals in zoos for human entertainment and pleasure.

The only true statement here is "green walls are one way for building owners to advertise their green credentials." It's just another form of greenwashing and justifying unnatural human environments by the superposition of a few natural specimens.

I always liked ivy-covered walls, but they can be bad for the masonry. In principle, why not create green walls by design?

Actually, perhaps the closest relation to this is urban performance art. It takes effort and serves no functional purpose, but enlivens the asphalt jungle for those who haunt its streets.

http://www.youtube.com/watch?v=2lXh2n0aPyw

Sure beats glass,cement ,an steel.

Criticizing the installation of green walls is a bit like criticizing the planting of street trees, the installation of green roofs, or even the construction of urban parks. I've lived in a house with an ivy-covered west wall, and besides mitigating afternoon heat gain, the ivy housed birds, lizards, and bugs. It was great (though it required a fair amount of effort to keep it in bounds). I'd love to see more green walls in urban settings.

Living walls provide multiple benefits in terms of providing habitat in urban areas and re-introducing appropriate regional planting to urban facades. I've worked on a couple of projects where such walls provided habitat for an endangered species of butterfly and plant species that were otherwise in the wane in the region. The true leader in this area is Patrick Blanc, a French botanist who pioneered the concept and a region-specific technology that is basically a trade secret. His is not a plug and play system or a wall of pockets where plants are tucked in like a row of flowerpots, it's about science.

As a Southern California apartment building owner and manager, I have found that growing vines on my buildings has had a number of positive effects including increased rents, cooler exterior temperatures and reduced exterior painting expenses. Of course, I also pay more to maintain the landscaping than most owners.

By using green walls, the buildings seem to recede from view and when you have to deal with small building lots, taking the emphasis off the stucco and putting it on the greenery allows our residents to feel they are escaping (somewhat) from the city.

You should read the article by George Irwin, Green Wall Editor at www.greenroofs.com "Death of a Green Wall". Great example of no fluff reality on green walls, not to mention if you want a pictorial dissertation contact them directly. He was a great help teaching our company about the reality of green walls. We were thinking about the Gsky wall and the failure rate and plant replacement was just too high for our life cost on the project. As for green washing I'm not opposed to the Eco-marketing opportunity I think it's awesome to see successful green walls vs print advertising or billboards.

Tony Marshallsay, there's nothing "kee-jerk" about being critical, even cynical, of yet one more attempt to pretty up a sinking Titanic while ignoring the imminent collision with reality. It's particularly ironic that all the "greening" of Riyadh you speak of with such admiration is made possible only by the conversion of an ancient earth-bound nation (Saudi Arabia) into the largest contributor to global warming in our fragile world.

I take issue with Robert Riversong's "knee-jerk" reaction to this article, because it seems to me that the company mentioned, GSky, has gone to great lengths to design green wall systems that recognize and avoid the problems that can occur with them - as far as is possible when one has no control over whether the O&M operator is responsible or not.

Further, I see nothing wrong in building owners using green walls to advertise their green credentials. To my mind, it isn't "greenwashing" - most of that occurs in sales blurb, nor is it attempting to justify an unnatural human environment - if you're going to take that attitude, we'd all still be clad in fur and living in natural caves! What it is, is shouting out loud: "I'm trying to make a difference - an improvement - to this often sterile modern world by bringing a bit more of Nature into people's working lives".

Riyadh, where I live, has of late experienced a "gray tsunami" of aluminum composite panel building cladding, which I would dearly love to see relieved by green walls, even if only up to a limited height; but the problems are the extremely dry atmosphere and high solar radiation, coupled with limited water supplies.

The city authorities have, however, "greened" it by providing parks, a considerable amount of planting in roadway median strips (including palm trees that produce dates) and trees in the sidewalks, together with landscaped highway intersections. Much of this planting is irrigated with TSE - treated sewage effluent - which is presently likely to be unacceptable for use in green wall applications in many locations around the world, no matter how good the purification, until the global fresh water supply becomes really desperate. And, unfortunately for us, it looks as if that time is rapidly approaching.

Great idea to help urban living and beauty but what is the cost and the cost to the building as far as maintenance? Also will it work in New England?

Great article, Brent. I've seen the Whole Foods green wall in Vancouver (pictured in the article) in person, and it's actually very aesthetically pleasing and adds to a neighbourhood "green" feel. In the future, I can see green walls (especially in urban setting) being used for small-scale agricultural production.

Any recommendations on how to convince a client that green walls can be worthwhile? My company recently completed a large-scale green roofing project for a local private school (video of growing media distribution: http://godfreyroofing.com/commercial/education/roofing-articles/video-gr...).... but we're very interested in encouraging them to take the next step and integrate green walls, too.

Again, thanks for the article!

Regards, Markus C. Ottawa, ON

Hi Marcus. Love the video. That’s quite an operation. Pam is right; there are some real-world concerns that need to be considered for each project and location so I'm not sure how much convincing I can do. A green wall is only as good as the long-term maintenance and plant upkeep, so any client should weigh these costs and the commitment against the benefits. Talking to a reputable green wall company would be a great place to start. They should be able to give a realistic assessment of the project. I could see a green wall giving the "ivy-covered school" look without the masonry damage, and with a green roof already installed at the school, a green wall might just be a good fit.

Thanks for the reply, Brent... I agree that the green wall only makes sense if the owner can commit to the necessary long-term maintenance/upkeep. This is probably one reason that a green wall may not be feasible for a lot of companies/homeowners.

Nonetheless, as you said, a green wall over top of a 'heritage' building such as the ones at Ashbury College could really enhance the 'ivy league' feel. As you suggested, we'll look for some reputable green wall companies in our area and talk to them about a potential partnership.

Cheers, Markus C. (Ottawa, Canada)http://www.godfreyroofing.com/

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