Could Labour build us out of the climate crisis?

This post is by Paul Brannen of Timber Development UK and former MEP.

The law of unintended consequences is always lying in wait for the unsuspecting politician. For instance, will Labour’s worthy commitment to build 1.5 million homes end up exacerbating climate breakdown?

Let’s begin with a salutary reminder. Concrete alone as a construction material is responsible for eight per cent of global carbon emissions. That is more than the whole of the EU’s emissions. Add in steel, insulation, bricks, breeze blocks and glass and we are looking at blowing all of England’s carbon budget on construction before 2050. Why? Because all these materials are energy intensive to manufacture which means – in an energy market still dominated by fossil fuels – that they all come with high levels of embodied carbon.

Building materials should be bio-materials
We need to shift from fossil fuel sourced materials to nature-based bio-materials. For instance, England needs to become more like Scotland, where currently 90 per cent of family homes are built using a timber frame; unlike south of the border where less than 20 per cent are. Likewise, insulation, which is currently 95 per cent+ fossil fuel based, needs to shift to wood fibre, hemp, straw, sheep’s wool, mycelium etc. Such nature-based products not only substitute for carbon intensive alternatives (reducing emissions) they also store carbon which they absorbed as CO₂ during their growth (removing emissions).

Calculations by Professor Michael Ramage at Cambridge University estimate that the construction of a 300m² four storey timber student residence would generate 126 tonnes of CO_2.  In comparison, the same building in concrete would result in 310 tonnes of CO₂ or 498 tonnes, if built from steel. Substituting the concrete or the steel for timber would ‘save’ 184 tonnes and 372 tonnes of CO₂ respectively. If you then factor in the 540 tonnes of carbon stored in the timber, you can argue the overall build is carbon neutral and results in the net storage of 394 tonnes of carbon.

Construction could become a climate solution
These figures enable us to see how we can turn the construction of homes from a climate problem into a climate solution. Some will question whether we need to build quite so many homes but, with the global population set to grow by a further two billion by 2050, the answer is self-evident. Most of these extra two billion people will live in mid to high rise blocks in cities. For the last 150 years, wood has not been a construction option for high rise, but that has changed due to the arrival of engineered or mass timbers with the structural strength of steel and concrete. This has led to the emergence of tall timber buildings, such as the world’s tallest at 85.4m in Norway. (All the evidence points to timber buildings being as fire safe as those made from any other material). That we can build mid rise housing with timber also means it can be used to enable greater urban densification, the primary way to avoid urban sprawl into the green belt.

Is there enough sustainable wood to enable this? Yes, is the simple answer. A combination of the following will deliver the timber needed to decarbonise the built environment: increased material efficiency (making better use of what we already have), improved forest management (to increase timber output and store more carbon), some forest expansion, more trees grown on farms (agroforestry) and a move towards harvesting a greater percentage of the net annual increment of trees growing across Europe (using over 100 per cent is not sustainable, and is not happening, but using less than 80 per cent is a missed opportunity).

Building regulations should drive the change
This change will not happen voluntarily and will need to be regulated. Existing building regulations (covering thermal performance, energy efficiency etc) are already driving many housebuilders, including Barratt, Taylor Wimpey, Vistry and Bellway, towards timber frames. This should be complemented with others to regulate and cap embodied carbon to help cut energy use during manufacture and drive changes throughout supply chains.

Actions Labour should take, if it comes to power, are to implement the Environmental Audit Committee’s proposal to legislate for mandatory whole life carbon assessment of all new buildings, as part of the planning permission process. This should include the amount of stored carbon. The next government should set maximum standards for the carbon footprints of new builds and their energy use and introduce incentives to use nature-based materials in construction, including insulation, recognising that carbon stored in buildings is a climate benefit. Education about the use of nature-based materials will be needed across the construction value chain. More commercial forest planting in the UK should increase sustainable wood supplies. Finally, the current government’s 2023 Timber in Construction Roadmap should be implemented.

If an incoming Labour government were to do all of that we should be able to turn the UK’s built environment from a carbon emitter into a carbon sink.

Paul Brannen is the author of  Timber! How wood can help save the world from climate breakdown which will be published in June 2024 and can be pre-ordered.