All political parties should make a manifesto commitment to move to reduce embodied carbon emissions in construction within two years of starting government, Will Arnold writes

If you were building a new house, and you wanted to enter the record books for “deepest foundation ever”, you could dig a hole to the centre of the Earth, and fill it with concrete. Provided there was nothing of interest directly below your construction site, there would be no regulation preventing you from doing this.

You would need to excavate about 10,000m3 of earth from the hole, buy many thousands of tonnes of cement, gravel, sand and water, make 3,000 journeys in a concrete wagon, and there would be some pretty interesting technical challenges along the way to ensure safe construction… but you would be within your legal rights to try.

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Your impact on the environment would be the emission of at least 2,000 tonnes of greenhouse gas into the atmosphere – more than 250 times the annual carbon footprint of that house’s owner. But don’t worry, that would not cause any legal challenges to your quest to go down in history for deepest foundation.

>> Also read: Building The Future Commission: Powering down the road to net-zero

The lack of regulation in this area means that one in 10 of the UK’s emissions now result from our use of construction materials and their resulting “embodied carbon” emissions.

Contrast this with UK regulation on energy efficiency. Since 2002, the Building Regulations have limited the amount of energy that a new home can use.

Over time, embodied carbon will become the majority of all emissions in construction

The Future Homes Standard promises to reduce this energy consumption further, and is set against a backdrop of an ever-greening electricity grid. Because of this, the Future Homes Hub released a report last year showing that, for new homes, more than 50% of each home’s lifetime emissions are embodied carbon emissions.

And, as the screws tighten on the use of energy and its associated carbon footprint, the ratio will grow and, over time, embodied carbon will become the majority of all emissions in construction.

That is not to say that industry has not been asking for change. In 2007, a report was published for the Department of Communities and Local Government which analysed a series of public consultations in this area.

The report was explicit, arguing that “the embodied energy of materials should be made part of Building Regulations.” However no significant action was taken by the DCLG in response to this, and similar subsequent industry advice over the past 17 years has likewise not been heard.

Half a generation after that report was published, you can still fill a hole to the centre of the Earth with concrete and no one will stop you on environmental grounds.

>> Also read: What the Future Homes Standard means for net zero

>> Also read: The UK is setting the standard for energy-efficient homes but there is still some way to go

Three years ago, I took on the challenge of trying to renew interest in such a cause, bringing together the UK’s leading embodied carbon experts, and creating Part Z, an “oven-ready” proposal of how embodied carbon could be regulated. We hoped that, by demonstrating the simplicity of such regulation (our proposal for an associated “approved document Z” was a mere seven pages long), we would galvanise interest in Westminster for tackling this area.

Since then, the proposal has gained the support of more than 200 companies, including household names such as Barratt Homes, Natwest and Wilmott Dixon. In their statements of support, these firms all say the same thing – they are trying to act on embodied carbon, but a lack of regulation is hampering them.

At the end of last year, I met with representatives from the UK Green Building Council and Built Environment Declares (wearing both my Institution of Structural Engineers and Part Z hats), who have been campaigning for embodied carbon regulation with vigour, particularly in recent years. We agreed that, with 2024 being an election year, the time was right to renew this call for embodied carbon regulation.

All polls are suggesting that the Labour Party will be in power by this time next year, and the three of us were agreed on the importance of embodied carbon finally making it onto the agenda for political leaders such as Kier Starmer.

Often, such a cross-industry collaboration on political asks would take time, but it only took a couple of weeks for our group to agree the text that we would all commit to asking for. It turns out that, despite the nuances of this topic, we agreed unanimously that it should be feasible for the government to regulate the measurement and reporting of embodied carbon (within the broader catch-all of “whole life carbon” that includes energy use) within two years of taking office, and introduce supporting limits two years later.

Of course, such regulation would start by only applying to large projects, with limits that most projects could meet comfortably, but this would finally get the UK on a road to tackling this 10% of its carbon footprint.

Another month later, and our small group had tripled in size, with the UK’s leading built environment institutions joining this renewed call for regulation. And, at the end of January, we published our one-page joint policy paper with its simple ask.

What the industry is asking for is no different to what other countries have already introduced as formal regulation

All 11 organisations are now asking for party leaders, including Starmer, to make the following manifesto commitment: “Our government will move to reduce embodied carbon emissions in building construction within two years of taking office”.

The following are specific steps:

  • Within six months of taking office: Policy signalled confirming the dates and interventions below.
  • By 2026: Mandate the measurement and reporting of whole-life carbon emissions for all projects with a gross internal area of more than 1000m2 or that create more than 10 dwellings.
  • By 2028: Introduce legal limits on the upfront embodied carbon emissions of such projects, with a view to future revision and tightening as required.

>> Read in full: Industry experts demand policy action in election year

Let’s be honest, there are still people out there who say that such an ask from industry is too difficult to fulfil. They argue that embodied carbon calculation methods are too immature and inconsistent, that it costs money for a design team to look at the emissions of their design, and that this will have too much of an impact on SMEs.

But what the industry is asking for is no different to what other countries have already introduced as formal regulation. France, the Netherlands, Sweden, Norway and Denmark have regulated embodied carbon already – as has California, which is the world’s fifth largest economy.

And the EU is now set to introduce similar rules if it passes the final stages of review in the next months (likely a formality). Surely the UK should be able to tackle this topic more quickly than the furthest corners of the EU?

Whichever political party next takes office in the UK, they need to have a robust plan for getting the country on track for net zero by 2050, and at a pace that is aligned with a 1.5°C future

And to those shouting about “the costs”, I would argue that they need to look at how much is currently being spent around the country due to individual developers and local authorities each trying to implement their own versions of embodied carbon limits while they wait for central action. The Greater London Authority and many other local councils are each developing their own approach to planning limits, and many private developers are requesting something different again. Responding to the variations between projects costs money – this is the cost of inaction, and one that is ultimately passed onto the public.

Whichever political party next takes office in the UK, they need to have a robust plan for getting the country on track for net zero by 2050, and at a pace that is aligned with a 1.5°C future. The science, and society, is clear as to that much.

Embodied carbon may not be a glamorous topic, and may not determine the swing of this year’s vote, but at 10% of the country’s emissions, it must be taken seriously if the next government is sincere about tackling climate change.

Will Arnold is head of climate action at IStructE