Wayne Hemingway is not known for mincing his words and as guest speaker at the press launch of Wolseley’s Sustainable Building Center, the ex-Red or Dead man, design consultant to Taylor Wimpey and chair of Building for Life, lived up to his straight talking reputation.

“A building isn’t sustainable,” he said, “if it’s s**t to live in.”

He went on to illustrate his point with a shot of a bleakly bricky apartment block that had, apparently, knotched up a good BREEAM eco-rating score.

“What does this look like?” he asked the audience, eliciting the sheepish response of “a prison?” from the back of the Sustainable Building Center theatre. “Exactly,” Hemingway responded, pressing his PowerPoint clicker to make barbed wire sprout up around the block. “You can load a building with eco-badges,” he said, “but if people don’t like it and don’t want to put down roots, it’s a slum of the future.”

Sustainability and design, he concluded, have to go together. “We’ve got to make sustainability something everyone wants to put in their house. We need to do sexy.”

Tim Pollard, Wolseley’s Vespa-riding head of sustainability, agreed, and added another ingredient into the mix – practicality. “We need pragmatic solutions; products that can be readily supplied in commercial quantities and delivered at affordable prices,” he said. “For long-term sustainability, you need short-term availability of the right materials.”

So, enter Wolseley’s Sustainable Building Center (SBC), a ground-breaking project, it proclaims, which represents a happy eco-construction marriage between high design and pragmatism – and, interestingly for this magazine, ties the knot with plenty of timber and engineered wood products.

The 6,800ft2 building in Leamington Spa is a living, breathing demonstration of the company’s sustainable products range (which now comprises 7,000 different items, all available via each of its 1,800 branches).

The challenge the company threw down to architect ECD (Energy Conscious Design) and contractor Sol Construction was to come up with a structure that looks and feels as good as it performs. It had to demonstrate that the various products work individually and together, and provide a generally conducive environment for the guided tours and events it will host for everyone from architects to self-builders. 

What it’s definitely not about, said Pollard, is eco-bling. Renewables, including solar thermal and PV systems, a ground-source heat pump and wood-fuelled boiler all feature, but they’re only included where they can make a solid contribution and provide practical solutions. “This building stresses the importance of the interaction of materials used, the performance of the envelope and other aspects, such as orientation,” he said. “These are simple things, but often overlooked.”

“There’s plenty of greenwash out there,” said Wolseley UK managing director Nigel Sibley. “But this is a solid statement of our intent to help make the building industry more sustainable.” And it’s a statement, he added, the company was willing to back with cash – a cool £3.2m.

At first the design brief might sound pretty constraining. But Mark Elton of ECD insists it wasn’t just a case of Wolseley telling him to cook up a building from a menu of their eco-products. “The first thing I did was ask for one of their catalogues,” he said. “But we also had freedom to bring in products to suit the design and purpose of the building. They just had to fit Wolseley’s stipulation of availability and affordability.”

The result is effectively a hybrid, using a grand total of 170 different products, with half the building in timber frame, half in prefabricated concrete panel. The latter, Pollard maintains, is about as green as concrete gets. The walls are Hanson Twin Wall, comprising two slabs joined with a steel lattice. These are craned into place and concrete poured into the cavity on site.

“Twin Wall gives rapid construction and you don’t need formwork,” he said. “It also uses 40% less cement than standard concrete and includes recycled slag.”

The floor, said Elton, pushes more green buttons. “We’ve used Hanson Cobiax panels, which include layers of plastic spheres that displace concrete where it has no structural benefit. This reduces the amount of cement and cuts the weight by 35%.”

The Kerto LVL edge beam supports the roof the length of the building

But while Wolseley is impressed with the concrete elements, it’s the timber that seems to get the bigger overall billing in the SBC. “We do generally have a lot of wood and timber products and really there’s nothing more sustainable for building,” said product development manager Chris Booker. “You grow the tree, which locks in the carbon, cut it down and plant another. And everything here is PEFC or FSC certified.”

The walls in the timber-based half of the SBC comprise open-frame panels based on a framework of Finnforest Kerto laminated veneer lumber (LVL) and OSB FJI I-joists. These were constructed by Sistem Carpentry and finished with 220mm of Rockwool insulation and plywood sheathing.

“We thought the panels would be prefabricated but, because of the curve of the wall, the chippy decided it was easier to build them up on site in line with the upstand,” said Elton.

The floor and ceiling panels are a similar structure, enclosing Uponor underfloor heating, but with deeper I-joists and 300mm of Alumasc Korklite insulation. “We used the different materials partly because these ceiling panels support the green roof and also because Wolseley wanted sections cut away to show different structures,” said Elton.

A common concern with timber frame is thermal mass and the risk of overheating but, said Booker, this shouldn’t be an issue at the SBC. “In some areas we’ve used Claytec panels, which are clay over an inner core of reeds with a hessian skin. This absorbs smell and moisture as well as heat,” he said.

Other walls and ceilings, he said, feature phase-change dry lining, comprising BASF’s Micronal polymer material in a sandwich of Knauf SmartBoard. This absorbs heat when the ambient temperature is over 23OC and purges it below 19OC.

Once it’s fully grown, added Booker, the building’s budding sedum roof will add another temperature regulating feature and the timber frame wing also includes ultra-energy efficient JELD-WEN High Profile triple-glazed, krypton-filled timber windows and doors.

“We wanted windows with a U-value under 1, but most available in the UK_ranged from 1.8-2.2 and only imported ranges of the style we needed came up to our standard,” said Booker. “So we went to JELD-WEN to develop a new range and High Profile is what they came up with. It has a U-value of 0.7, and we could have achieved 0.3 with xenon gas. The certified redwood frame also has 30 year guarantee against rot and 10 years for the paint so it’s pretty much a fit and forget product.”

Timber also infiltrates the masonry section of the SBC in the form of the Seufert-Niklaus glazed façade and the roof structure. The former was prefabricated in Germany and trucked to Leamington. “It’s an impressive product, with the glulam mullions playing a structural role,” said Elton.

The roof comprises Kerto LVL beams and a deck made in a sheet form of the same material, finished with a Lindab Aluzinc standing seam outer skin. “We also used a Kerto edge beam the length of the building to support the roof,” said Elton. “This was built up in layers and there was a hold your breath moment when the formwork was taken away, but it stayed up!”
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ompleting the eco-building package, the whole SBC sits on a concrete slab foundation using 60% GGBS, lighting blends automatic LED and CFL systems with Glidevale “sun scoops” and the external finish is a mix of Finnforest thermowood cladding, lime render and Ibstock Fireborn clay blockwork. There are also areas of thermowood decking and a Kerto pergola where visitors can sit in eco-splendour and enjoy what will eventually be landscaped surroundings.

Besides a product showcase, the building will be a test bed, with the energy performance of the structure and interaction of the various materials and systems constantly monitored.

And Wolseley is confident the SBC will meet its prime objective of demonstrating that green construction can be practical and affordable. The fact that it had already been booked for 132 events from June to September hints that it has also satisfied Hemingway’s aspiration for sexy sustainability.

Kerto LVL was used for the roof beams and deck

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