RFP Magazine

Verdant Living: Forget potted plants, the new trend in city greening is to make the buildings from the plants themselves. It’s vertical greening, inside and out.

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The latest fashion in buildings is covering our cities like a cosy green blanket. This fashion continues to grow quite literally, without human intervention. It started with green roofs and trickled down to greener balconies and the odd terraced affair until suddenly walls, indoors and out, are resplendent in leafy, frond covered goodness. It is no longer just an aesthetic trend, buildings managers are saving money this way, developers are selling units this way and some future thinkers see green walls, roofs and vertical farms are the solution to the future urban food crisis

New technology controversy

New green walls, ceilings and roofs differ from traditional landscaping or trellis arrangements. Landscapers or architects specify three broad format types: • Traditional trellises have given way to state of the art mounting systems that cling to and curve around structures up to any height. Designers train creepers and vines to grow around these systems. • Forget the ivy covered mansions of old, technically advanced products allow other plants to grow on or into the hard fabric of the building.

Examples include organic concrete structures such as the award winning forms created by French/Brazilian firm Tripytique. Its Edifício Harmonia//57, in São Paulo is an office building created with perforated organic concrete where plants have been inserted up and down the walls with the eventual goal of turning the entire building into a bushy mass. A misting system of pipes that snake a foot away from the surface of the façade waters the plants. • Wall coverings of organic substances (earth or a substitute) or completely hydroponic systems have appeared in array of styles and designs that can accept many more varieties of plants and allow for indoor and out door wall art that Jeff Koons would be proud of.

Aesthetic vs. engineering vs. FM benefits

Many of the now legion of green wall product suppliers were previously engineering or non-landscape product related. S3i for example used to make stainless steel rigging for yachts, which they developed into a green wall system. Nick Arrowsmith of S3i says his existing rigging product made of steel wire affixed by brackets work well for architects who wanted a structure that plants could grow on that affixed to the building exterior. Any size walls could use this solution, he explains, though architects and buildings owners should watch out for the impact on building snow, wind and water load because when used extensively the system could “act like a sail”. Likewise finding a planting solution on super tall structures like sky scrapers would present landscapers with a challenge, he notes.

All systems come with their own engineering challenges but in the aesthetic area green walling designers are confronted with their greatest, though often overlooked, opportunities. Arrowsmith says his system winds around buildings and walls and can be made into any shape or design, citing a recent project at Heathrow Airport where they sheathed and beautified a car park building. He encourages designers to be inventive with the system capabilities: “we would like people to take our product and do something daft with it” he says.

Like S3i, many companies in the field started as product or engineering companies says Mark Lawrence, a landscape architect who became so enthusiastic about green walling that he developed his own product. In his case, he launched BioTecture, a company dedicated to designing and implementing green wall systems for buildings and the built environment. Using his system, plants are grown vertically in a modular, hydroponic-fed system. Close groups of bushes can be grown to create amazing shapes and designs. From a design perspective Lawrence has a palette of plants that he likes to work with, while other designers using the same or different systems might choose others. He says design often comes as the final consideration while technical issues are of primary concern to building owners.

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Lawrence has worked in partnership with one of the most famous green wall designers, Patrick Blanc, a scientist who developed a light weight hydroponic system that can be attached to large and small walls, pillars and even ceilings. He is responsible for some of the most spectacular green walls all over the world. Beautiful designs that meld both engineering and sensitivity to horticultural aesthetics means people now know him as one of the first ‘designers’ of this artform while others grapple with technological issues. However, as one horticultualist points out, olfactory beauty and practical usage such as for shade can be created using simple trellis designs and the right species. Though spiky, bougainvillea makes a beautiful choice in warmer climes as do choices such as red or white manevilla, clematis and jasmine, which has the added advantage of no spikes, does not drop fruit and attracts birds, it does however have a tendency to grow woody with age so levels close to the planting area will need to be supplemented with other plants.

But are they actually green?

According to Lawrence the benefits of green walling include reduced thermal loading on buildings, water and air filtration, reduced heat island effect, sound and storm water attenuation, creation of urban ecological habitat, plus exciting and uplifting human urban environments. With so many product crepping into the market buys beware of unknown long-term management pitfalls, he warns. For example, some soil or compost based systems will see a degradation of the quality of the material over time and other cell based systems may build up deposits of fer ilising minerals, but no one knows. Likewise those systems based on porous or perforated material might find the holes clog up and require extra maintenance. Finally, some systems are ‘greener’ than others, he notes, with water usage and management being the key concern. Some hydroponic systems he says use up to 10 times as much water as his own, making them unsuitable or even irresponsible in arid districts.

The edible wall

The 2008 Chelsea Flower Show was awash with green walls and roofs this year. Lawrence already has plans to exhibit a prototype edible wall in 2009.  hile this prototype currently only displays salad greens, he hopes that in the future it can provide a future solution to the urban food crisis. Urban farming is a popular notion, with more radical proponents believing that the whole food production cycle could be moved into multi-storey buildings in cities that would both save space and food transportation dilemmas.  

Advocates of urban farming point to more sustainable production helping to produce more crops while reducing the transportation, land use and use of pesticides and fossil fuels required by many other farming systems. One of the downsides is that vertical farms require artificial light and heat, especially on the lower floors and there is still debate over whether the seemingly obvious gains would be outweighed by the environmental cost of building and maintaining the structures. However with the idea only having been seriously proposed in 1999 by a Professor Dickinson Despommier of Public Health at Colubia University, it still has some way to go.

The advantage of vertical farming over Lawrence’s edible wall is that they are, or can be, more easily protected from the elements and the extreme weather events that plague farmers now and are expected with global warming to increase dramatically in number. But they could easily have crops and plants outdoors and in. And it’s not just food that can be farmed downtown, one of the most recent developments is the discovery of the high oil content of green algae, hitherto unfairly referred to as ‘pond scum’, that can be grown on arterial cells vertically and many people, including major global governments are putting significant research into its cultivation for biodiesel. This can be done in similar conditions to other types of vertical farming and could be used to create biodiesel in situ. While the market for algae biodiesel now is not driven by aesthetics, but whose to say that in the future the Patrick Blanc of iceberg lettuce and pond scum won’t be creating works of art that both feed us and power the cities of the future.

DIY?
For the creative facility manager you can even learn how to replace fossil fuels currently used to run machinery with biodiesel from substances as rich in oil as algae. Huge research dollars are being poured into this field by some of the world’s biggest energy companie such as Shell, but the savvy property manager or even home owner can even make it on their premises. See making-biodiesel-books.com. Note that the website warns this is not a ‘simple afternoon venture’.