Are you sitting sustainably?

12 November 2012

AHEC’s latest project for the London Design Festival merged design with sustainability. Sally Spencer reports

Creativity, manufacturing, further education and life cycle analysis met seamlessly at the Victoria & Albert Museum as part of the London Design Festival (LDF) in September.

It was all thanks to a groundbreaking eight-month project between the American Hardwood Export Council (AHEC), the Royal College of Art (RCA), Benchmark Furniture and sustainability consultancy PE International.

AHEC is no stranger to the international design community, or to the LDF, having worked with architects and engineers such as David Adjaye, Established & Sons, Matteo Thun, Sou Fujimoto, Arup and Amanda Levete - the latter on the now iconic Timber Wave at last year's event.

This year, however, its attention turned to the designers of the future by engaging with RCA Design Products students and challenging them to design - and make - a functional chair or seat in the American hardwood of their choice. The added twist was that the students had to record all the production data during the manufacturing process, including the quantities of the materials used and the time spent on each machine. This allowed them to create a Life Cycle Impact for each chair.

AHEC recently published an ISO-conforming report, prepared by PE International, on the life cycle assessment (LCA) of 19 American hardwood species and this project - dubbed "Out of the Woods: Adventures of 12 Hardwood Chairs" - provided "an insight into how our LCA data can be practically applied to product design and manufacturing", said David Venables, AHEC's European director.

First, of course, the chairs, which were designed under the tutelage of Sebastian Wrong and Harry Richardson, had to be made and that's where internationally renowned Benchmark Furniture, founded nearly 30 years ago by Sean Sutcliffe and Sir Terence Conran, came in.

The students camped out in Benchmark's grounds by night and hit the workshops by day, when the company's craftsmen helped them turn their ideas into reality.

The students' enthusiasm for their projects was heightened by their new-found awareness of the manufacturing process and the Life Cycle Impact.

Questioning definitions
They had come to the project with many assumptions about the best way of incorporating sustainability into their designs but the discipline of recording material and energy inputs really made them question their own definitions of the term. And this re-evaluation resulted in many different approaches.

Some, for example, used unprocessed wood to reduce energy inputs, while some increased their reliance on recycled or waste products of other processes, such as woodchips and offcuts. Others focused on creating "classical" designs that would survive the vagaries of changing fashions, reasoning that longevity was a component part of sustainability.

Nic Gardner and David Horan cut down on the volume of material used when they created their flat-pack bench "Phyllida". It can support the weight of eight people yet can easily be carried from location to location under one arm.

Its chunky legs were created by coiling two lengths of 1.5mm-thick cross-laminated veneer into double-walled cylinders and slotting them into circular grooves cut into the underside of the seat - a solid, two metre-long plank. The components required comparatively little machining and the students' choice of the plentiful species tulipwood, which possesses the highest strength-to-weight ratio of all American hardwoods, helped them achieve a bench with a low environmental impact.

Meanwhile, Nic Wallenberg avoided steam bending or press moulding in the creation of his stackable chair "Squeeze" by developing a technique to form structural bends from straight lengths of inherently flexible American hickory.

He discovered that by machining asymmetrically positioned slots through the thickness of the timber, it was possible to squeeze the outside edges together with a simple bolt that forces the wood to bend in a
predictable manner. Applying this technique to the design required placing four of these timber "pinches" around the frame of the seat and back, on which were glued thin skins of hickory-veneered plywood.

The environmental profiles generated for each design suggest that none of them are perfect in terms of their environmental impact - Squeeze, for example, was judged to have a lifespan of only 5-10 years - but the experience of matching design and manufacturing with LCA is invaluable, as is its legacy.

"We have been able to confirm the potential for wood to play a very positive role and to specifically inform the debate about how to measure accurate environmental profiles for designs in American hardwoods," said David Venables, adding that AHEC planned to build on what has been learned to help refine sustainability tools for the design community.

"We believe this pioneering, collaborative and practical demonstration is essential if we are to provide meaningful criteria for assessing true sustainability," he said. "This kind of work needs to happen across the wood sector, and in other industries, so that policy-makers can establish environmental frameworks that have real meaning and deliver real change."

? A technical publication Out of the Woods: The Creation of 12 Hardwood Chairs is available to download or order free of charge by visiting

Copies of a companion piece, Out of the Woods: Adventures of 12 Hardwood Chairs, for which some of the best writers in the UK were asked to write a poem or short story on the chairs are also available by request via the website; or to download as an iPad app by searching "Out of the Woods".

Nic Wallenberg’s Squeeze chair involved bending American hickory without using steam bending or press moulding. Source:Petr Krejci