For plants, it seems, indoors is the new outdoors. While the benefits of accessible, well-maintained exterior green space are now well established, interior landscaping can have at least as great a role in health and productivity. And this means significant opportunities for interior landscapers across the world, heard delegates at the first ever European Interior Landscaping Organisation (EILO) congress in the Netherlands last week.
According to EILO chairman Jon Lans: "As an industry, we have been around for several decades, yet are still quite unknown. But by exchanging information, we can build a bigger industry. A lot of research has been done since NASA first started looking at the effect of plants on the atmosphere back in 1989. EILO aims to be the central source of research on the benefits of interior landscapes, and that can be used to lobby for standards in building, including accreditation schemes."
The Flower Council of Holland (FCH) promotes plants in the workplace through its pan-European initiative, Plants for People. UK director Jonathon Read told congress delegates: "There are increasing numbers of arguments why plants are persuasive for your customers. You can contribute to their health - and their wealth."
To back up this claim, FCH has published a guide, Pots of Health, which summarises research findings in an accessible way that can be put before potential customers.
"Indoor plants don't just look pretty, they are good for you, for several reasons - cleaner air, improved humidity, fewer headaches and minor ailments, lower stress, reduced absenteeism, improved concentration and creativity and higher productivity," says Read. "All these are supported by independent research. Suppliers should be using these arguments with their customers - don't let them take it for granted. They probably don't care much about horticulture, but there are sound financial reasons to have plants in your workplace. Talk their language."
US researcher Dr Bill Wolverton was principal investigator on NASA's pioneering study on the role of plants in air pollution reduction in the 1980s. Last month, a work he co-authored, Plants: Why You Can't Live Without Them, was published in the UK. "The mere presence of plants has been proved to lessen environmental pollution, increase labour productivity and reduce the cost of health care," he says.
Interior planting consultant Bob Capel, who has over 20 years of experience in the sector, says: "I think it's about to take off again as people become more aware of the benefits. Health benefits lead to financial benefits through lower absenteeism."
Green Fortune, which has headquarters in Sweden, is an urban greening specialist responsible for around 100 sites in 12 countries. Among these is Amsterdam's Conscious Hotel Vondelpark, in which the company has installed interior green wall panels as part of a recent refurbishment. According to the company's Netherlands representative Eelco Schutter: "Companies want to show they are green-minded. This communicates their green aspirations, as well as creating a nice atmosphere."
Green wall formats are as relevant to indoor landscaping as outdoor landscaping, according to Modulogreen operations manager Hans van Cooten. "They can be an integral part of the building - you can even make a facade that starts outside and continues inside. When we show this to architects, they go crazy. Last week I met one who is designing a restaurant that will have herbs and salads growing on the wall - you can even pick out the one you want for your plate."
But while interior greening is already popular among pioneering organisations, several speakers at the conference said the trend will take a major step towards the mainstream thanks to environmental accreditation schemes, which are becoming more prevalent across the developed world.
"At the moment, plants don't feature in the green building standards - you can have a fantastically green office without any plants," says Indoor Garden Design joint managing director David Grace.
Creative director Ian Drummond adds: "It's a message that European Federation of Interior Landscapers Group (EFIG) is pushing heavily, though it will take time to produce results."
Key among these accreditation schemes in the UK and also the Dutch construction sector is BREEAM, the most widely used environmental assessment method for buildings, which is administered by consultancy BRE Group. According to EFIG chairman Thomas Palfreyman: "BREEAM is currently being revised and they have confirmed the inclusion of interior planting and maintenance, as part of the recommendations which will be decided on in January."
Former EFIG chairman Alan Page adds: "It's important that plants should be professionally maintained if they are to provide the full benefit to the users of a building and we have pushed for that in the BREEAM review."
However, a BREEAM representative claims otherwise, saying: "BREEAM 2011 will be released early next year in line with changes in legislation. But while we have taken on various recommendations, the inclusion of plants within buildings is unlikely to form part of the new assessment standards."
Mike Lewis is president of US industry lobby Green Plants for Green Buildings, which has campaigned for inclusion of interior planting in standards for the Leadership in Energy & Environmental Design (LEED) system, the North American equivalent of BREEAM. "We have focused on their role in improving indoor air quality because that's where the research is," says Lewis.
Jonathon Read points to the success of the Green Star accreditation system in Australia, New Zealand and South Africa, which already include credits for indoor planting. "Eleven per cent of Australian offices are now Green Star certified, and that's only in the last 10 years," he says.
Many countries now have Green Building Councils and an international umbrella group, the World Green Building Council, says it "supports the adoption and ongoing development of market-based green building transformation systems that meet local needs for each country" - though it "does not promote any particular system or methodology as a global standard".
Mike Lewis adds: "Globally, we are at the tipping point. If we can push this through now, we can make historic changes."
IN AT THE GROUND FLOOR
Designers and their clients should include provision for indoor planting at the earliest stages of building design, according to a building consultant to the Dutch Government.
SIGN consultancy programme director Peter Oei told the EILO conference: "No one thinks about plants when they start building. But you can work with architects at an early stage - they are generalists who require specialist help."
He urged interior landscapers to think big. "Architects don't like one plant in one pot. You have to sell them a landscape of maybe 200 plants," he said.
Large modern glass structures greatly extend the scope for indoor planting, he added, but this increases the need for specialist input from the plant world. "Light is good for people and plants," he said. "But in a recent development in Frankfurt, the plants died because the wrong sort of glass was used."
Expertise from the Dutch glasshouse sector also shows how heat exchangers can balance out temperature through the year in other sorts of buildings, he added. "We need buildings that produce, rather than consume, energy."
Glassed-in play areas in schools - already a feature of several schemes in the Netherlands - would also allow year-round use, he suggested, "and planting would improve air quality in schools, which has been found to be worse than in prisons." But he said of green walls: "We have to be able to provide at an affordable cost. They are still quite expensive."
According to Indoor Garden Design creative director Ian Drummond: "All our work comes from architects and designers and they have picked up on what we did at Chelsea this year. But don't want leave it till they're moving the desks in."
Joint managing director David Grace added: "People are thinking about plants in the office environment as being more than just a pot plant stuck in the corner."
INDOOR LANDSCAPE SECTOR
The UK indoor landscape installation and maintenance sector accounts consist of 350 to 400 companies whose annual turnover amounts to over £80m, according to European Federation of Interior Landscape Groups (EFIG) chairman Thomas Palfreyman.
Nine out of 10 clients opt for rental-and-maintenance deals, rather than outright ownership of the plants. And around 90 per cent of UK indoor plants are soil-grown, unlike on the Continent, where close to half of indoor plants are grown hydroponically.
EFIG was one of five founding organisations of EILO in 2006. Last week's event organiser Sander Kroll points out that the wait for this year's congress has been worth it.
"I would have been happy with 200 delegates," she says, "but we got 250, from 20 countries, not just Europe. We might have it every second year from now on - it will depend on feedback."