But buildings like these are designed pretty much exclusively for the plants. What about buildings built for people? A relentless procession of competition-winning building designs are liberally sprinkled with "green stuff" in the most unlikely places. Ralph Erskine's Greenwich Village proposal showed fully grown trees atop the medium-rise housing blocks and Foster and Partners' Commerzbank in Frankfurt virtually had forests in the four-storey cranked atrium spaces of the skyscraper. It is a similar story with Ken Yeang's eco-towers for Elephant & Castle.
The actual buildings rarely manage to capture the green essence of the planting in quite the same way as the architectural visualisations. Progressing from concept to scheme design, the Commerzbank's planted areas succumbed to reality as the soil zones were reduced to 800 mm – not enough for the large trees. Finally, at detailed design, the remaining plants were put into ungainly planters for the office workers to wander around during their lunch breaks.
When plants do make it into the more conceivable places – atriums, foyers and lobbies – they are put there like refugees, huddled together in pots and obviously anaemic from lack of light or too much light, poor humidity control and dreadful soil conditions. The plants that get to enjoy the outdoors on balconies and roof terraces soon get ripped to shreds by high winds, soil erosion and lack of irrigation. The few surviving vines end up caked in grey pollutant particles. And then we cheat: the worn out green stuff is swapped by maintenance companies at regular intervals. This is hardy sustainable design.
Fortunately, there are also some success stories. Grass roof technology is now well developed, and good examples range from the permanent roof at Chris Wilkinson's Science Museum in Bristol, to the grass pitched sedum roofing at the temporary building for the Almeida theatre in King's Cross.
Plants in atriums and lobbies sit like refugees, huddled together, anaemic from lack of light
At the cutting edge of technology, a vast amount of research into sustainable planting has been undertaken by the space agency NASA over the past few years. Experiments with fully sustainable communities of plants and people in biodomes have been undertaken to see if this is a way of establishing space stations. The less esoteric findings are useful for building design. These include autonomous self-regulated irrigation systems, artificial sunlight and even data on which plants are best suited to absorbing toxins from the air within buildings. Such toxins come from fixtures and fittings, people and external pollutants. Rubber plants and swiss cheese plants do particularly well.
These methods will shortly be put to the test when three 20 metre eco-towers are constructed next to the A13 in Barking, a particularly toxic artery in and out of east London. The towers are designed to look like pure foliage throughout the year. This idea was conceived by artist Tom de Paor and should provide valuable information that can be used in other buildings.
There is still a concern about using technology to get plants to live happily inside buildings designed for, and used by, people. The industry is now familiar with sick building syndrome, and perhaps the plants are telling us something when they wilt in our built spaces. Rather like a canary in a mine, plants are hypersensitive to dangerous conditions for humans. Building designers can inadvertently rely on the resilience of humans to survive unpleasant living and working places.
We love our parks and the countryside. Open green spaces allow us a break from stuffy buildings where we work increasingly long hours. It is time for a new approach to green buildings: if the environment works for plants, it should be able to work for people too. Even a few simple changes can help do the trick. For example, air intakes for offices are often at the polluted street level. Why not raise them and take the air through scented planted areas of a roof garden?
Postscript
Tom Barker is a director of b consultants, a building design practice specialising in technology and innovation.
