by John Gendall

Summary: Though often consigned in perception to countryside lodges and single-family suburban homes, wood is gaining renewed credibility as a structural material among a growing group of contemporary designers. Owing to its sustainability virtues, structural possibilities, and low cost relative to steel, wood is cropping up in new markets. Take London, for example, where, at nine stories, the world’s tallest timber residential building opened at the end of February. There, in a dense urban setting, Murray Grove is challenging traditional ideas of wood construction.

Waugh Thistleton, a young London-based firm that designed the 29-unit building, called for wood to be used in load-bearing walls, floor slabs, stairwells, and elevator cores.

“As a practice, we’ve always been concerned with the environmental impact of building material,” explains Waugh Thistleton principal Andrew Waugh. “We’ve been looking at ways of reducing the impact of a building in terms of energy use, including the emissions caused by the actual production of materials themselves.”

“When you’re looking at doing a concrete or steel building, you have to consider the emissions created during the manufacturing process, which can be quite staggering,” according to Waugh. He then set out to find a wood system that would perform in a nine-story urban building.

He turned to KLH, an Austrian manufacturer of engineered wood products. He chose a cross-laminated timber, made by adhering a series of wood members perpendicularly, giving it a robust strength. KLH uses a solvent-free, formaldehyde-free adhesive, an important criteria for Waugh. He was further drawn to the company since it uses wood off-cuts generated in the manufacturing process to power its factory with biomass.

“The structural performance is fantastic,” exclaims Waugh. “The tolerances are great, it doesn’t move under compression, and it weighs a quarter of what a concrete structure would weigh.”

“Murray Grove is a brilliant structure,” says Vahik Enjily, international director of Building Resource Establishment (BRE), a London-based organization that provides testing, certification, and research services for the building industry. “It overcomes the problems of connecting different members together,” he adds. “This building would easily compete with concrete and steel.”

BRE has recently performed a major timber research initiative, the TF2000, in which it submitted trial six-story timber structures to a battery of performance tests, demonstrating the effectiveness of timber structures in fire protection, durability, and acoustic performance.

“There are many advantages to using timber,” explains Enjily. “The material itself is renewable and sustainable, provided it is from a certified forest; you can do anything you want with it architecturally; the overall cost of building is cheaper; you don’t need massive foundations for a timber frame because of its lightness; and you can incorporate and change technologies into timber buildings very easily.”

Wood itself is undergoing significant changes of its own, with a new generation of material scientists and fabricators identifying emerging possibilities for wood. “Much of the innovation with wood now comes by rethinking wood, taking it from a traditional to a more advanced material,” explains Naree Phinyawatana, of Atelier Ten, a New York-based environmental design consultant. “Many of the emerging trends in wood involve cutting it down, breaking it up, and reconstituting it as a way to make it structurally stronger,” she adds. These advances in reclaimed and recycled wood products—such as KLH’s cross-laminated timber panels—are redefining the material.

Atelier Ten often calls for wood. Along with Hopkins Architects, from London, it recently completed Kroon Hall for Yale’s School of Forestry & Environmental Studies, which employs wood as both structure and cladding. As a renewable material, the environmental benefits are manifold. Pointing out that wood stores carbon, Waugh explains that the amount of carbon stored in Murray Grove’s material and saved from not using concrete is equivalent to 21 years worth of carbon emissions from an equivalent building of this size.

Phinyawatana also highlights the environmental benefits of using wood. “Be mindful of the FSC-label,” she cautions, referring to the designation of timber cut from responsibly managed forests, which is administered by the Forest Stewardship Council (FSC). “When using reclaimed and recycled wood, always check that product’s percentage of FSC-certified wood,” she adds. “And, as always, make sure it’s a regional material—that its production and extraction comes from within 500 miles of the building.”

Ben Travel, Gensler’s regional technical leader in San Francisco, suggests one of wood’s most salient roles is as a conveyer of meaning. “Wood is used now not so much for structure as it is for the cladding in order to communicate greenness,” states Travel. “People want to advertise a building’s sustainability, so we turn to wood, often in the superstructure or the cladding, as a way to do that.”

Waugh, however, took a different approach with Murray Grove, concealing its wood, with a taut gray, black and white skin that blends into the urban context. He called for 5,000 individual panels made with 70 percent waste timber to clad the building. These form a pixilated pattern, animating the building’s surface and giving a decidedly contemporary and urban appeal.

Regardless of message, the medium is the focus of renewed attention. “Working with wood was such a simple and straightforward process,” says Waugh. “The only thing we did not anticipate was the ease of using it.”