The spread of vegetal facades

Mar 4, 2015 by


Responding to concern over the loss of green space in cities, architects are exploring ways of making plant elements an integral part of their buildings

Imagine the office of the future. Remember that most of us spend more than a third of our lives at work. That equates to 90,360 hours, according to Sean Cassidy and Joe Wilson, architects of the Organic Grid, the winning entry to NYC-based Metropolis Magazine’s recent Workplace of the Future competition. Organic Grid is Cassidy and Wilson’s vision of how today’s offices can be transformed into destinations that benefit our health. They propose plants, moveable walls, meeting rooms and food-growing pods that can be built on to retrofitted buildings.

Until recently, vegetal facades usually meant a green wall by Patrick Blanc or landscaped balustrades by Ken Yeang – well-intentioned though largely symbolic gestures to introduce planting into buildings. Now, in response to ever-mounting concern about loss of green space in cities, several architects are exploring new approaches.

Architect Stefano Boeri’s Bosco Verticale in Milan incorporates almost 17,000 trees, shrubs and plants into the facades of two residential towers. Three years of research went into the choice of species, specifically selected to suit different orientations and exposures. The trees and shrubs are planted in relatively conventional balcony containers reinforced to resist winds, yet the thoroughness of the research and the ambition of the project are considerable. Who wouldn’t enjoy living with a balcony full of plants?

Collaborating with Patrick Blanc, Atelier Jean Nouvel has pushed the approach one step further at One Central Park in Sydney, where approximately 50 per cent of the facades of two residential towers are covered with plants. Climbing and hanging plants are supported on hydroponic walls consisting of felt pouches anchored within a steel mesh. At the ZAC St Just project in Marseilles, a mixed-income housing project of close to 500 units, set to go on site late this year, Nouvel is proposing a south-west courtyard elevation invaded with pines and cactuses, evoking the region’s rocky inlets, the calanques.

Until recently, most vegetal facades were well-intentioned symbolic gestures

Due to complete later this year, M6B2 (named after the project’s lot number) is a social housing project by Edouard Francois, another Parisian architect, currently on site in the city’s 13th arrondissement. Its four blocks include an 18-storey titanium-clad Tower of Biodiversity, which will be covered with plants grown in 3.5m-long stainless steel tubes fixed to the facade. Test plants were grown in trial tubes at the Paris botanical gardens during 2012/13 to check the approach’s viability.

Here in the UK, BDP’s £288 million Alder Hey Children’s Hospital in Liverpool, expected to complete in June, features undulating wildflower meadow roofs. Comprised of three wards, which form fingers extending into the park, the hospital is built into the slope of the site, making the green roofs appear to merge into the parkland setting. The edge of the hospital site incorporates a ha-ha to further blur the boundary with the adjacent park.

ARUP is monitoring bioresponsive algae facdes at the BIQ building in Hamburg

ARUP is monitoring bioresponsive algae facdes at the BIQ building in Hamburg

Introduction of algae is another approach to vegetal facades. Arup has been involved in trialling bioresponsive algae facades as part of a double-skin facade in the BIQ building, constructed as part of the International Building Exhibition (IBA) in Hamburg in 2013. According to Arup associate director Jan Wurm, preliminary monitoring results demonstrate that the BIQ building is net zero energy. The current goal is to find a commercial use for the building’s algae biomass byproduct, perhaps in the food or cosmetics industry, in order to secure a business plan for this technology. A prototype for a building-integrated algae panel is under development and would reduce costs by eliminating the need for a double-skin facade.

Also exploring the application of algae in buildings, S333 Architects is working with engineer Battle McCarthy, the University of Greenwich and University College London to incorporate algae bioreactors and aquaponic walls into a 46-unit residential tower in Lagos, Nigeria. In association with the University of Greenwich, Battle McCarthy also leads Greenworks, a biotechnology and city farming ideas hub, which develops affordable solutions for leasehold properties and community groups.

Who wouldn’t enjoy living with a balcony full of plants?

So what does this motley array of approaches – from containers on balconies to algae tubes – say about the way forward for vegetal facades? While it’s early days, to see clients such as Hines Italia in Milan and social housing provider Paris Habitat back these approaches is significant. Initiatives of other progressive clients provide further clues. Both Google in its Central St Giles offices and WWF-UK its Hopkins-designed headquarters in Woking have created workspaces that open on to balconies with allotments, recognising the health and community-building benefits in this approach.

Cassidy and Wilson set out to produce their Organic Grid as a blueprint for 2050. ‘We always felt the concept could be applied to a skyscraper, individual office or even a warehouse,’ says Cassidy. ‘At this point, it is of course conceptual; however, some of the best inventions in history must have started out as the craziest of ideas.’ We need more approaches with the boldness of Wilson and Cassidy’s Organic Grid. And hopefully we won’t have to wait until 2050.

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