Akey statistic that came out at the recent American Hardwood Export Council (AHEC) European Convention held positives and negatives.

Delivered by AHEC executive director Mike Snow to the audience of 120 US suppliers and their European customers gathered in Budapest, it was the fact that the American hardwood forest, having seen a growth-to-removal ratio of two trees to one for 50 years, could sustainably support a harvest four times current levels.

The good news is that the US can use this figure to lay claim to having some of the most renewable hardwood around. Less good is that it also highlights the global market failing to make the most of this abundant resource, with potential downsides for the US hardwood forest.

"In fact, the UN Forest Products review expresses concern that it is now severely under-utilised," said Mr Snow.

One danger in once managed forest being left unharvested, he explained, was that it became less diverse and dynamic.

"A healthy, profitable timber industry is also vital to keeping forest land as forest land. Without it, there’s more incentive to convert to other uses."

AHEC is under no illusion about the scale of the challenge this poses and sees it as threefold. To fully exploit the capabilities of its resource demands development of new markets and new timber applications. Faced with increasingly bold environmental claims for rival materials, plus increasingly stringent proof of timber legality requirements worldwide, it also requires ever-stronger evidence of its green credentials. Over the two days of the Convention, however, speakers highlighted progress being made on all these fronts, with more to come.

Why US forest growth is so out of kilter with timber harvest is mainly because of a contraction in sawmilling, with 40% of plants going in five years and capacity now down 50% on 2005.

"The US housing crash and recession contributed to this, but they compounded an existing trend caused by overseas migration of US timber products manufacture," said Mr Snow. "This, plus the effect of the downturn, is also reflected in the timber we’re producing. Eight years ago the graded to industrial lumber ratio was 60/40. Today it’s the opposite."

The industry has not, however, stood idly by as domestic graded lumber demand has contracted and its key adaptation has been to reorient overseas.

"We now export 18% of production and that total includes 46% of graded output and 60% of No 2 common and above," said Mr Snow. "And we’ve seen growth for the last four years, giving us a market-leading 20% of global trade."

Biggest growth has, predictably, come in China, now importing around 1.2 million m³ of US hardwood annually, and Mr Snow doesn’t expect its demand to "top out any time soon".

"China’s rising costs mean it’s no longer just the big screwdriver, sucking in raw materials for re-export as cheap finished goods," he said. "Instead, it’s become a massive consumer market. We estimate 80% of its US hardwood imports are already for domestic consumption and latest forecasts are for a 234 million rise in Chinese middle class households by 2020."

AHEC also sees increasing upward social mobility benefiting US hardwoods in other emerging industrial powers; hence such marketing projects as its competition for Indonesian furniture design students.

Europe remains key market

And as these economies step up, the US hardwood sector is also focusing on latest ‘screwdriver’ markets, like Vietnam and Mexico. But at the same time, it is far from turning its back on western Europe.

"Europe may have suffered in the downturn, with construction 25% down on 2008, and US hardwood sales down in value a further 3% in the first six months at U$129m," said Mr Snow, "but it’s still among our most valuable markets and we’re now seeing growth and improving economic sentiment, notably in the UK and Germany, but with signs of recovery even in southern markets."

Among the industry’s efforts to expand US hardwoods’ potential through improved technical capability, and to underpin this and environmental performance with science, the convention heard that thermal and other modification is showing increasing promise.

"It’s a growing market, with European annual heat treatment production now around 300,000m³ and global 400,000m³," said Neil Summers of Timber Dimension, which is researching the field with AHEC. "And we’ve shown it is applicable to a range of US species, including ash, tulipwood, soft maple, red oak, yellow birch, hickory and pecan."

Trials with Teknos coatings had further enhanced the material’s potential, added Mr Summers, and tests at Italy’s CATAS labs showed a range of thermally modified species, including tulipwood, achieving durability class 1.

Scott Seyler of Northland Forest Products, which supplies various heat-treated hardwoods under the Cambia brand, acknowledged the US still lagged in heat-treatment capacity, with just 10 producers. "But we’re seeing it specified increasingly," he said.

The convention also heard that AHEC’s environmental life cycle analysis (LCA) work continues to gain momentum. Rupert Oliver of Forest Industries Intelligence described LCA as a "real and current science", with growing commercial relevance. It was being built into Environmental Product Declarations (EPDs), which were becoming key to the competitiveness of building products, and was a vital element in the rapidly developing field of Building Information Modelling (BIM).

The major cradle-to-gate LCA study of US hardwoods by PE International commissioned by AHEC, said Mr Oliver, had now been turned into a practical i-report tool.

"This can be used to dynamically generate environmental profiles for 19 species, with the ability to adapt to different parameters." David Hopkins, head of communications at the UK Timber Trade Federation and marketing campaign Wood for Good, underlined the growing international "market mainstreaming" of EPDs, LCA and BIM, and their increasing dovetailing with green building codes. Under its Wood First Plus initiative, he added, Wood for Good was also creating an online timber LCA resource, including AHEC’s data, as a tool for use with BIM and for developing EPDs.

"This information is becoming commercially critical, as in ‘no data, no sale’," he said.

An equally powerful case for timber LCA was made in an impassioned presentation from Sean Sutcliffe of UK furniture maker Benchmark. His company was involved in AHEC’s "Out of the Woods" project, which challenged UK Royal College of Art students to design chairs that scored on aesthetics and performance, but were also informed by full LCA, covering the timber and all other materials and inputs.

"The process turned the students into design ambassadors for the environmental and technical performance of US hardwood, and opened their eyes to the value of LCA, as it did ours," said Mr Sutcliffe. "In fact, Benchmark is now working on its first commercial furniture range in American cherry with full LCA."

Equally passionate were the speakers presenting AHEC’s Endless Stair project, a showcase initiative which even more clearly and powerfully combined its efforts to prove and communicate US hardwoods’ environmental credentials and technical potential, in this case in the form of an engineered product for structural applications.

This comprised a 7.7m-high structure of interlocking flights of stairs made entirely in US tulipwood cross-laminated timber (CLT). It formed the central showpiece of the London Design Festival in September, erected outside the iconic Tate Modern Museum and followed in the footsteps of previous AHEC headlining projects for the event: the tulipwood Sclera pavilion and laminated red oak Timber Wave.

Engineered timber triumph

"But this was our most technically demanding and ground-breaking Festival project to date – hence the huge media coverage," said AHEC European director David Venables. "It demonstrated the structural potential of engineered US hardwood, and using No 2 common tulipwood highlighted the opportunities for using lower grades in high specification projects. And it was also backed with full LCA."

Endless Stair was an international venture; designed by architects dRMM and engineered by Arup, both of the UK, with the CLT sections fabricated by Imola Legno of Italy, the finished stair built by Nüssli of Switzerland – and AHEC members, of course, supplying the timber.

Chad Cole of Imola Legno described how it had developed an approach to further maximise use of the raw material.

"Instead of ripping to standard sizes, we selected and bonded random-width boards to the required dimensions, hiding less attractive material in the inner layers," he said.

Project engineer Andrew Lawrence was clearly impressed with the performance of the material and said Endless Stair could lead to further engineered hardwood structural projects.

"In fact, it’s already produced two real enquiries for using hardwood CLT," he said.

Dramatic though the Endless Stair project was, the AHEC convention saved probably its biggest news splash to last. Following comments that widespread certification of US hardwood remained unlikely because of forest ownership fragmentation and that, as the EUTR became more embedded, EU buyers might demand additional detail on timber origin and other green issues, it was announced that a new form of evidence of US hardwoods’ environmental credentials rolls out in months.

The American Hardwood Environmental Profile, explained Mr Snow, coalesced other AHEC environmental validation initiatives into a single tool for creating an environmental profile shipping document for each hardwood consignment. These include PE International’s LCA work and the Seneca Creek national risk assessment study – to be updated in 2014. It incorporates FSC Risk Register data and is aligned to EUTR proof of legality requirements, and it also uses PE International LCA software, enabling suppliers to automatically calculate a range of other environmental impacts.

It would, said Mr Snow, prove an invaluable marketing aid for US hardwoods worldwide. "And it will highlight that other materials now have to stand up and provide equivalent information," he said.