Embodied carbon and the planning system

What is embodied carbon and why is it important?

There is no standard definition of "embodied carbon" in planning legislation or policy.  However, it is generally understood to mean the greenhouse gas emissions associated with constructing a building (and depending on the scope of the assessment also taking it down at the end of its life) as opposed to the "operational carbon" associated with using the building. The embodied carbon and operational carbon together form part of the building's whole of life carbon emissions.

While there is still much to do, the real estate industry has made significant strides in reducing operational carbon through everything from energy efficient lighting to onsite solar PV. This means that the relative significance of embodied carbon is increasing. Although embodied carbon has not had the same level of focus as operational carbon to date, there is now widespread agreement that embodied carbon needs to be effectively measured and assessed if the built environment is to play its part in meeting the Government's legal binding target of achieving net zero by 2050. 

How is embodied carbon assessed in the planning system?

It is more of a debate perhaps than a pure methodical assessment. At a national level, there is no specific requirement for embodied carbon to be addressed in planning policies or planning decision-making. It would, however, fall within the wider planning considerations relating to climate change. In this regard, the Planning and Compulsory Purchase Act 2004 (as amended by the Planning Act 2008) imposes a statutory requirement for development plans to include policies designed to ensure that the development and use of land contributes to climate change mitigation and adaption.

The National Planning Policy Framework similarly provides that strategic policies must address climate change mitigation and adaption, with the more detailed paragraphs on meeting the challenge of climate change  recognising that the planning system should, among other things, encourage the reuse of existing resources and the conversion of existing buildings. Any local requirements for the sustainability of buildings are required to reflect Government policy. 

Local plans must conform to the statutory duty and also reflect the NPPF. However, the specific policies addressing embodied carbon in developments vary from local authority to local authority. The London Plan provides one of the most robust examples, with whole life cycle carbon assessments, including an assessment of embodied carbon, required for developments that are referable to the Mayor and encouraged for all other developments.  Local authorities such as Westminster City Council (through its "retrofit first" policies in the partial review of its City Plan) and the City of London Corporation (through its draft embodied carbon planning guidance) are taking a similar approach. This demonstrates that requiring embodied carbon to be assessed and limited at the planning stage is feasible, although some local authorities are further along this road than others. 

Even where local authorities do not have express planning policies requiring embodied carbon to be assessed, it is increasingly expected that the overall carbon impact of a development will be considered at the planning stage. This may be encouraged by local authorities under the wider umbrella of climate change planning policies or driven by industry initiatives such as the UK Net Zero Carbon Buildings Standard; RICS and RIBA guidance, and the UKGBC's Net Zero Whole Life Carbon Roadmap. This trend is set to continue.

Are planning reforms to address embodied carbon expected or as an industry should we demand such reforms?

While the direction of travel at local authority level is towards requiring embodied carbon to be assessed as part of the planning process, the absence of nationally agreed standards and regulation is a source of uncertainty for developers and communities. This has played out in high profile planning appeals where the embodied carbon consequences of demolition vs retrofitting have been up for debate, as well as in calls for a new "Grade III listing" status to protect buildings from being demolished if they are capable of re-use.

Although Grade III listing does not seem imminent, it is likely that national policies for assessing embodied carbon will come forward. The House of Commons Environmental Audit Committee found that the "single most significant" policy the Government could introduce to improve the sustainability of the built environment would be a mandatory requirement to undertake whole-life carbon assessments for buildings, set within building regulations and the planning system.  

In its response, the Government has committed to consulting on the measurement and reduction of embodied carbon.  Further changes to address embodied carbon were also trailed in the government's December 2022 consultation on changes to the NPPF, with the government seeking views on how carbon assessments should be deployed in planning policy and decision-making. The government's response to this consultation is currently awaited.

The question for many is therefore not whether changes to the planning system will be forthcoming but whether such changes will happen soon enough and go far enough to have a meaningful impact on tackling the climate crisis. In February 2023, the Rt Honourable Chris Skidmore’s Mission Zero: Independent Review of Net Zero made 129 recommendations and overall the message from that body of work can be summed up as go harder, go faster with reforms to deliver Net Zero.  

Standardised methodologies for calculating and assessing the carbon impacts of a development (including embodied carbon) and guidance on taking this into account in planning decision making would be a welcome start. However, recent calls by industry leaders for plan-making and planning decisions to explicitly align with the UK's carbon budgets, driven by concerns that the planning system is not currently fit for purpose,  illustrate a wider school of thought that a more fundamental overhaul of the planning system is required. 

This article was first published in LexisNexis.