The Government’s roadmap for increasing timber use in construction is here, but how is the industry tackling the obstacles? James Parker spoke to Andrew Carpenter, chief executive of the Structural Timber Association.
How can structural timber, the ultimate sustainable material option, regain its place on the specification agenda? Facing a combination of a long-standing stigma around fire safety on sites, misconceptions around moisture issues and buildability, and recently supply, inflation and the post-Grenfell war on combustible materials, the timber industry was feeling somewhat unloved.
There has been widespread cynicism from homeowners since media coverage in the late 1980s of poor practice in masonry plus timber housebuilding. The timber industry has been repairing its reputation ever since, such as Barratt Homes (the subject of a seminal 80s World in Action timber exposé) doing an internal exercise among its younger staff to look at the appetite for timber frame. With the 1980s now a distant memory but the climate crisis now front of mind, those staff advocated a return to timber frame.
The Roadmap
Having spent months lobbying government, the Structural Timber Association (STA) celebrated when Defra launched the Timber in Construction (TiC) Policy Roadmap in December; a practical framework for increasing the use of timber in construction. It was the result of close collaboration between the industry and the Government to identify the steps needed to drastically increase adoption in the race to net zero 2050.
The working group behind the document included DLUHC, the Department of Business and Trade, and the Forestry Commission. The construction and supply chain sectors had passionate advocates in Andrew Carpenter, chief executive of the STA, plus Timber Development UK’s Dave Hopkins, and Andy Leitch of the Confederation of Forest Industries. Augmented by industry associations like the HBF, the wide-ranging and influential voices on the panel meant the issues were vocally expressed, and ownership guaranteed.
With 2050 net zero looming ever larger, and the Future Homes Standard 2025 imminent, the STA contributed research and data to the working group to help understand the impact its widespread use could have on reducing CO2 in housebuilding. However the group also looked at barriers to adoption, and ways to overcome them. Seven key recommendations emerged to make up the roadmap, labelled Supply, Demand, Building Safety, Labour & Skills, Carbon, Insurance, and Innovation.
Carpenter said that with the recommendations now in place, the roadmap gives “clarity and reassurances to stakeholders throughout the construction industry.” However, have we made any progress down the road?
The agenda behind the roadmap, which traces back to COP26 in Glasgow, was to “safely use more timber in construction.” The two major drivers were the climate crisis and the safety agenda following the Hackitt report on building safety, post-Grenfell. Andrew Carpenter of the STA says that within the working group, the imperative was that “you don’t choose a net zero solution that’s not safe, and you don’t have a safe solution that’s not net zero.” Carpenter praises the Government’s approach to grappling with the need to pursue ways to enable timber to form part of the specification agenda: “They have played a blinder.”
Supply & Demand
Andrew Carpenter says that the working group identified the need for the UK industry to use more homegrown timber. He says that according to the STA’s research, around 50% of the carbon emitted from timber supply in the UK is from transportation. “It’s still considerably less than steel and concrete, but if we want to improve, it’s the transport side that’s the biggest problem.”
Carpenter believes that “quite an education process” was required to meet the group’s goals – firstly the Forestry Commission needed to grow the right species, and increase forestry from its current 14.5% cover to 16.5% in the UK. However, to enable this to occur, he says “we need to create a market, and the Government has recognised that that market is construction.” However, Carpenter added that the construction industry needed to understand that it is acceptable to use softer timber varieties than received wisdom may suggest, to benefit UK sourced timber. “We need to educate the sector that they can use C16 timber rather than C24; that is a big stumbling block.”
“The other question mark,” says Carpenter, is around the capacity of the industry to deliver, which “will not be overnight,” meaning many suppliers will still need to import the majority of their timber. He says that the Environmental Audit Committee has asked for a minimum of 40% of housing to be timber frame, nearly doubling the current 23% figure; “ideally they’d like it to be 80%” (the target in Scotland). Carpenter asserts: “If we get 40% my sector would be quite happy.”
The second priority for the roadmap was looking at “how are we going to create that demand in the industry, what’s the incentive,” says Carpenter. He asserts that the major housebuilders are driving it “to a degree,” citing how Barratt purchased STA member Oregon Timber Frame around three years ago. They “have invested heavily” in a new £40m-plus factory in the Midlands, and Taylor Wimpey’s new £45m Peterborough factory building timber-framed homes.
He adds: “Persimmon has had Space4 in their supply chain for ages, Cala Homes has bought Taylor Lane, Vistry has just bought Countryside with its three factories.” He says that this shows that commercially “it stacks up,” but adds “we need to fill in the gaps,” giving one example of how the STA was that day meeting the leading group of London housing associations G15 to hear their views and drive forward the agenda. England, where the big potential currently is for timber, is “behind the curve” on growing compared with UK devolved governments, admits Carpenter.
Timber’s sustainability is a given, but the roadmap working group is “interrogating it far more than just embodied carbon to look at whole life, end of life, and EPDs (Environmental Product Declarations). Carpenter said “at the moment we seem to be fixated on a 60 year building life, but we think it should be double that,” but admitted that degree of shift would be unlikely.
Fire safety agenda forms one of the key priorities, and the STA has worked for many years to bring rigour to timber design and specification (collected in its ‘16 steps to fire safety and the STA Assure fire safety audit scheme). Post-Building Safety Act, Carpenter says that allied to “early involvement of all the key players,” dangerous specification switching is far less likely. Although ostensibly for over 18 metres, the “culture has cascaded down through the industry,” he asserts.
Persuading the insurance sector remains a major nut to crack, of course. With the post-Grenfell environment seeing a ban on all combustible materials over 18 metres, we are a long way from seeing the innovation in sustainable high-rise timber buildings many hoped for, in the short term. A working group has been set up with the insurance industry via the Association of British Insurers to “try and look at their issues and concerns.”
Skills, Cost & Innovation
Carpenter says the skills issue is “probably the elephant in the room,” even questioning whether architects have the skills to design in timber. Many may assume that designers love timber, but there’s a lack of specific timber-oriented training currently, says Carpenter, so he is working with the RIBA currently on developing a technical helpline, alongside the STA’s existing training scheme for contractors assembling timber frames.
The final part of the puzzle is innovation: Homes England now requires 55% of MMC-oriented projects to provide ‘premanufactured value’ ie factory assembly, as a prerequisite for funding. STA members are innovating further in response, adding more elements such as doors and windows offsite.
Cost may continue to be a stumbling block here, and STA is producing an “extensive” cross-sector cost comparison with other materials like masonry, with consultant Rider Levitt Bucknall. And, with a greater push towards controlled, innovative offsite methods, unforeseen costs should be reduced.
The timber ‘roadmap’ is just a start, and the Election may see a shift in priorities, but you’d expect such a key piece of thinking to survive the political upheaval. Could we soon see a step change in specification of timber across the industry, but also, long term, from UK sources? The biggest immediate question is whether the construction industry can supply the necessary demand to support the investment and innovation.
In terms of the impetus for tackling climate change, “the direction we are on as a society is unstoppable,” says Carpenter. For now, industry and Government have finally seen the sense in pursuing the answers collaboratively.