Measuring embodied carbon – how the South West is leading the way

We all know that reducing emissions from the construction sector is critical to the UK reaching net zero and with zero carbon targets fast approaching, policy is coming forward to meet the embodied carbon challenge.

The Environmental Audit Committee has recommended all local authorities adopt measures by 2025, and some authorities have brought, or are bringing, requirements forward. The Greater London Authority has already adopted embodied carbon rules. Now, Bath and North East Somerset Council (B&NES) has become the first council outside London to introduce embodied carbon limits for new build projects.

B&NES has set a new limit of 900kgCO2e/m² for large residential and commercial developments. It is an ambitious target but is realistic for developers to meet if they work together with their design team and contractors. The local authority is also the first in England to have an adopted local plan policy requiring a net zero energy balance for new housing.

Measuring embodied carbon is complicated, however, and there is no one standard approach in terms of what to include and what assumptions to make.

Enacting new rules in the B&NES area has been a steep learning curve for all involved. The council first had to agree a consistent methodology for calculating embodied carbon. This required a collaborative approach involving a number of partners with the right expertise. In this case, for example, the team also worked with the University of Bath and has subsequently partnered with it so the university can use its expertise to monitor, analyse and investigate the policy’s implementation.

What developers need to know

With these new requirements in place, it’s more important than ever that developers have the right team of experts in place to design projects. For some, this could mean bringing engineers into their discussions with architects much earlier on. These experts are essential to ensuring designs submitted for planning don’t inadvertently ‘lock in’ high embodied carbon design decisions.

It’s also important that developers look to open a dialogue with the council as soon as possible, to ensure targets are met and, critically, calculations are accurate and transparent.

As other councils begin to adopt requirements, what’s needed may vary. Checking with each council on what calculations they’re expecting to see will be key to avoiding miscommunication and delays to projects.

A change in culture

Applicants and decision makers must be upskilled to ensure at least a basic understanding of how calculating embodied carbon works. There are a number of resources available for upskilling, such as through discipline institutions, the UKGBC website and the Buro Happold website.

Project teams must also be more flexible with project designs earlier in their development processes, and engineers, for instance, will need to be comfortable working with uncertainty. At the very early stage of planning processes, there are more unknowns. For example, the team may not know where building materials are being sourced from, or the exact reinforcement quantities required in the concrete elements. But this should not stop a rough assessment of the embodied carbon costs being calculated.

If you are building outside of the B&NES area and London, you may think these new rules don’t affect you, but ultimately, calculating embodied carbon limits looks set to become the industry standard. Understanding these new requirements, and how they might differ between authorities, will soon be critical for developers and consultant teams across the country.