The north London Council declared in May that it would be considering a “wood first” policy containing a presumption in favour of sustainable timber in new build projects. The move is backed by environmental campaigners, who wish to see it rolled out across all local councils.
But the concrete centre says design presumptions may prevent the most appropriate material being chosen. Executive director Andrew Minson said the move was based on research that “incorrectly suggests that timber is carbon negative, which in whole life terms is simply not the case”.
“It is not enough to just cherry pick sustainability benefits,” he added. “A presumptive bias at planning stage means that the benefits of each construction material are not being fully considered nor the decision made by the appropriate design professionals.”
The centre’s objections to timber centre on what they say are misconceptions about the green credentials of the building material, which they claim can produce up to 22 times as much carbon dioxide as concrete.
They cite Timber Research and Development Association figures that estimate that timber, over a 100-year lifespan, generates between 400 and 980kg of carbon dioxide per tonne. According to the centre’s own figures, concrete produces just 40-140kg per tonne.
The centre also objected to the environmental costs of importing timber from abroad, the effects of fire-proofing and sound insulation, and of preventing house vibration.
But sustainability campaign Wood for Good head of external affairs David Hopkins disputed the figures, saying they hugely exaggerated the amount of timber that ended up in landfill. He also denounced the “myths” of fire hazard and sound insulation problems, which he said were less significant in wooden buildings.
He added that “a recent study into hardwoods imported to the UK from North America found that even when transportation across the Atlantic is taken into account, the amount of C02 absorbed by trees before they are harvested more than offsets the carbon released by production and export”.
He said: “We, and Hackney, are not calling for Wood Only – just to ensure that developers have at least weighed up the options in favour of using timber in their developments.”
The council stressed that it was “keen to promote the benefits of building with wood, [but] it is not considering a policy that would exclude locally sourced building materials or prevent the use of other sustainable building materials in future developments”.
A spokesperson said: “We aren’t looking to adopt a rigid policy which disregards the use of other traditional building materials. Rather we will be seeking to inform industry leaders of the benefits of building with wood and how it can complement the national sustainability agenda.”
Hackney’s councillor for regeneration and the Olympics, Guy Nicholson, said the construction industry was “increasingly recognising the aesthetic and environmental benefits of using wood in new developments”.
The borough is home to the so-called Graphite Apartments, made entirely from wood from the second floor up. At nine storeys, the building is one of the tallest wooden residential constructions in the world. Amid speculation of legal action, the council is asking for feedback on its “Wood First” policy to be sent to email@example.com.