Paul Brannen, Author at Red Brick

There is a growing awareness that using more timber in construction would be good for the climate. Using wood substitutes for materials with much larger climate footprints i.e. concrete, steel, brick and block[1]. At the same time wood stores carbon that has been removed from the atmosphere via photosynthesis while the tree was growing in the forest. After the tree is harvested a new one is planted.

Technically this process is not Carbon Capture and Storage (CCS) rather it is a Greenhouse Gas Removal (GGR). However both processes are removing carbon from the atmosphere and storing it: the former, theoretically, for centuries[2]; the latter for decades. In the battle to avert climate breakdown both are needed.

Talk of CCS can elicit strong emotions. Its detractors, particularly amongst the green NGOs, point out that to date it has proved expensive and unreliable resulting in its development being slow. On the other hand its advocates, all big players – the UN, the Committee on Climate Change and the Labour Government – insist it is a key part of the architecture that will deliver net zero.

CCS’s UK champion, Energy Secretary Ed Miliband, has secured nearly £22 billion of government funding to subsidise three projects on Teesside and Merseyside that will carry captured carbon to geological storage in Liverpool Bay and the North Sea resulting in the removal of 8.5 Mt CO₂e each year from the atmosphere.

How does GGR via carbon stored in timber construction compare to CCS in the amount of carbon it can remove from the atmosphere? The answer comes from adding together four GGR categories delivered by using more wood in buildings.

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First, we have timber framed 2 or 3 storey family homes. Currently 92% of family homes built in Scotland have timber frames. England is now following, albeit from a low starting base of 9%. This change is happening for two main reasons: timber framed homes have a lower level of embodied carbon than a brick and block equivalent and they can be erected more quickly which financially benefits the housebuilder. The timber frame is also storing carbon at a rate of 4.6 tonnes per home. Consequently if 45% of the 300,000 family homes planned to be built each year had a timber frame this would store 0.6 Mt CO₂e annually.

Second, we have carbon storing wood fibre insulation of which little is currently used in the UK unlike in Germany and Poland where figures are approaching 10% of new homes. If 20% of new homes in the UK used it this would store 0.2 Mt CO₂e annually.

[Wood fibre insulation has the potential to be a major carbon store in both new and existing buildings – picture Steico]

Third, is mass timber which delivers much larger GGR figures. Mass timber is a bigger version of plywood where layers of wood are stuck together at right angles to produce a material which has the same structural strength of steel and concrete. With it we can construct big buildings – stations, mosques, offices, apartment blocks, schools. A recent study, by architects dRMM, focused on five case studies which concluded that each mass timber building stored on average 1,032 tonnes of carbon. If 300 cities and towns were to use mass timber to build 20 new buildings per year this would deliver removals of 6.2 Mt CO₂e.

[Architects dRMM have studied five mass timber builds in the UK revealing them as major carbon stores as well as healthy buildings]

Fourth, if each of these mass timber buildings used wood fibre insulation we would have a GGR of 1.5 Mt CO₂e per year.

In total this would deliver an annual carbon removal of 8.5 Mt CO₂e – equivalent to the UK’s proposed CCS programme – and at no financial cost to the Treasury!

[Sweden is leading the way with a steady increase in the number of mid-rise apartments built for timber – picture author]

Quite why such a massive carbon removal opportunity remains essentially unrecognised by the government is a mystery. Is the technology not exciting enough? Is it because it cuts across three departmental silos (Housing, Energy and Environment) and isn’t seen as ‘belonging’ to any of them? Is it – oddly – because it doesn’t come with a significant price tag?

The government’s Timber in Construction Roadmap 2025 is its first step towards addressing the housing crisis in a sustainable way. While the government don’t need to finance GGR via more timber in buildings they do need to:

Acknowledge publicly at cabinet level that timber buildings store carbon and that such GGRs are good for the climate.
Use government procurement to boost timber construction as is in France and Japan.
Include biogenic carbon in the embodied carbon assessment within net zero whole life carbon policy in the construction sector.

When it comes to Greenhouse Gas Removal technology now is the time to see the wood from the trees.

[1] This is because their manufacture involves high levels of heat, in most cases derived from a fossil fuel energy source.

[2] Off the coast of Norway two CCS operations at Sleipner and Snohvit have been capturing a million tonnes of CO2 annually for 27 years and 15 years respectively, so not yet centuries.

Can a Labour government build more homes without exacerbating climate breakdown?

By Paul Brannen, former MEP 2014-19

With 40 per cent of global climate emissions sourced from the built environment, a future Labour government will need to be alert to the danger that its welcome pledge to build 1.5 million homes could exacerbate climate breakdown. The good news is that the exact opposite is also possible: every desperately needed new home could also help address the climate crisis.

Why is the built environment such a major cause of climate breakdown? Concrete, steel, bricks and breeze blocks can only be manufactured using large amounts of energy, energy which is still predominately sourced from the burning of fossil fuels. Concrete is an acute problem because, as well as the energy needed, the manufacturing process of extracting the lime from the limestone triggers a chemical reaction resulting in the release of CO₂ into the atmosphere. In fact, concrete is responsible for a staggering eight per cent of total global carbon emissions. Steel is almost as problematic but is partly redeemed by its high recycling rates. Currently, virtually everything we build has an unnecessarily large carbon footprint.

The CO₂ emissions do not cease once construction is complete, as buildings in the UK typically need to be heated for more than half the year and, increasingly, cooled for the rest of the year due to warmer summers. Again, this is mainly done using energy sourced from fossil fuels. In this case, the solution is much better insulation but, even our newbuilds use far greater energy than those in comparable countries.

[Global CO2 emissions by sector – source UN Environmental Global Status Report 2017]

Is there then a material out there that we could use as a substitute for concrete, steel, brick and block? Yes: Timber! Scotland, Canada, the USA and the Nordic countries build 80 per cent of their family homes with timber frames. But England builds less than 20 per cent. Does it matter? Yes. Timber’s carbon footprint is considerably lower than most construction materials, plus it also stores carbon – a virtue that will be of increasing importance in achieving net zero.

Recent developments with a material known as engineered timber (or mass timber in North America) mean that it is now possible to build at height and at scale with timber in urban settings. Labour-led Hackney Council, has the largest concentration of engineered timber buildings in the world – including flats, offices, a cinema and a church.

[Murray Grove, Hackney, London – the world’s first modern engineered timber tower at nine storeys, built in 2009, Waugh Thistleton Architects]

Professor Michael Ramage of the University of Cambridge calculated that erecting a 300-square-metre, four-storey student residence in wood generated only 126 tonnes of CO₂ emissions. If it had been made with concrete the tally would have risen to 310 tonnes. If steel had been used emissions would have topped 498 tonnes. Indeed, the building can be viewed as “carbon negative” as there is the equivalent of 540 tonnes of CO₂ stored in the wood, resulting in a long-term subtraction of CO₂ from the atmosphere.

A switch to building more with wood rightly raises questions around the supply of sustainable timber, forests, biodiversity, land availability, fire risk and timber builds. I have set out to answer these questions in detail in my forthcoming book Timber! How wood can help save the world from climate breakdown. Suffice to say the construction industry can provide answers to these questions.

Hopefully a Labour government will be up for the switch to timber for the sake of the climate. If so, what should they do to encourage a greater use of timber in construction? Six specific steps should be promoted by an incoming Labour government:

1. Implement the Environmental Audit Committee’s proposal to legislate for mandatory whole-life carbon assessment of all new buildings, including the amount of stored carbon, as part of the planning permission process.

2. Set maximum standards for the carbon footprints of new builds and their energy use, which can then be tightened over time as we aim for net zero in 2050.

3. Incentivise the use of nature-based materials such as timber in construction, including insulation, in part by recognising that the storage of carbon in buildings is a climate benefit.

4. Facilitate education about the use of nature-based materials across the whole of the construction-value chain.

5. Increase the home-grown sustainable wood supply by increasing commercial forest planting.

6. Implement the current government’s 2023 Timber in Construction Roadmap which includes working with industry and academia to identify opportunities and barriers to the use of timber in retrofit and promote best practice and innovation by 2027.

Labour is right to state that there is no magic money tree. There is, however – when it comes to tackling climate breakdown – a magic timber tree. A Labour government can deliver the homes the country desperately needs, and at the same time turn the built environment into a carbon sink rather than a carbon emitter. A win-win for Labour, the country and the climate.

[There are 1,000 tonnes of carbon safely stored in the timber used to construct the new Founder’s Building at the University of Washington. This climate benefit was recognised, monetised and sold for $150,000].

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Timber! How wood can help save the world from climate breakdown will be published in June 2024 and can be pre-ordered https://www.waterstones.com/book/timber/paul-brannen/9781788217354