Global expansion

5 April 2014


Advances in engineered timber include the development of UK-manufactured products. Peter Wilson reports.

The last few years have seen the global market for engineered timber expanding dramatically, not only in the volumes of material used, but also in the range of products.

The UK has been one of the readiest markets for products such as cross-laminated timber (CLT) but other products, such as laminated veneered lumber (LVL), are now beginning to create their own niche as architects, engineers and other construction professionals begin to recognise the value of timber products that can be used individually, in combination or in hybrid form with other materials to achieve new design solutions capable of meeting existing and forthcoming legislation.

The psychological move away from concrete and steel solutions and towards engineered timber has certainly been driven by low carbon and environmental imperatives, but also by the opportunities offered by these products.

The ability to build taller in timber is one that has struck a chord internationally with architects and engineers. The Stadthaus in Hackney's Murray Grove by Waugh Thistleton Architects and engineers Techniker pioneered the route to higher and denser urban housing constructed from solid timber, and provided the exemplar for others in Melbourne, Bergen and Vancouver to follow. London has undoubtedly been leading this charge, with several very large housing projects now being built from CLT in the capital's east end and at Elephant and Castle.

Where London leads, other cities follow and it is not only in the world of new build that engineered timber scores, but also in the potentially huge retrofit market. Densification of the urban landscape is attractive to developers and politicians alike and is leading to fresh thinking on existing regulations that have, to date, mitigated against the use of timber in town centre locations. In Aberdeen, for example, proposals are afoot to build five storeys of accommodation on top of a threestorey city centre bar and restaurant, the lighter weight timber structure capable of being carried on existing foundations.

Rethinking urban life
Other engineered timbers have stepped up to the plate in this rethinking of urban life in the 21st century, the most notable example being the Metropol Parasol by German architect Jürgen Mayer-Hermann in Seville's La Encarnación square, a vast covered market place constructed entirely from LVL. Currently the largest timber structure anywhere in the world, the project has taken this particular engineered timber product into new territory and stimulated an exponential growth in interest in LVL's structural potential, The product can now be found on projects in the UK such as the retrofit Edinburgh Centre for Carbon Innovation or the external and internal portals of the new visitor centre at Abbotsford, Sir Walter Scott's Scottish borders' house.

To date almost all CLT, glulam and LVL has been manufactured from softwoods, but Grupo Gamiz produces hardwood glulam in Spain's Basque country, while Pollmeier is bringing Germany's vast European beech resource into use in the manufacture of hardwood LVL. Both products offer extremely high strength and thus smaller section sizes, both benefits in structural design, while the use of hardwoods increases the potential for external, visible use.

The UK currently imports almost all of the products mentioned above, there being no domestic manufacturer yet of CLT or LVL. While glulam has been a construction staple since the 1960s, it is only relatively recently that its manufacture from UK-grown softwood has been available from Buckland Timber and in bespoke form from Inwood. And the possibility of CLT being manufactured from home-grown material draws ever nearer, with three years of R&D work at Edinburgh Napier University providing the objective, generic information on the available timber resource, manufacture, market and commercial viability necessary to attract the required investment in large-scale manufacturing facilities.

At the other end of the spectrum, the Wood Products Innovation Gateway, an ERDF-supported project at Edinburgh Napier University's Institute for Sustainable Construction, has been working with SMEs around the country to develop dowelled laminated timber, known as Dowel-Lam (Brettstapel) and nailed stacked plank systems, known as Nail-Lam. Both products are relatively unknown in the UK market, although the former has been used in imported form in several projects in Scotland. Small-scale, localised manufacture that brings sawmill and production close together is the key here, reducing transport costs and supporting (mostly) rural employment and thereby sustaining communities. Engineered timber not only has environmental benefits, it can have a social purpose too.

  • Peter Wilson is an architect and director of the Wood Studio research centre within Edinburgh Napier University's Institute for Sustainable Construction.

The Metropol Parasol in Seville
LVL was used in the new Abbotsford visitor centre