Embodied carbon and whole life cycle assessment – progress towards net zero and the construction industry

Introduction

An important but currently absent aspect of the Government’s response to ‘net zero by 2050’ is ‘embodied carbon’. Embodied carbon is a term which identifies carbon emissions related to the creation of anything in the built environment[1]. In this way, it is distinct from operational carbon emissions – it concerns construction rather than use. For example, the carbon emissions involved in mining of raw resources, processing raw resources, and use of processed resources in construction could be embodied carbon. Depending on the methodology used, embodied carbon might also extend to decommissioning emissions too[2]. A ‘whole life cycle’ assessment of carbon emissions would be one which takes into account both the embodied, operational, and decommissioning carbon emissions.

Progress towards whole life cycle assessment

Whole life cycle assessments of carbon emissions are not currently standardised nor mandated. However, Government policy and legal obligations means that addressing embodied carbon is something that the Government is unlikely to let lie much longer. The UK built environment is responsible for approximately 25% of total UK greenhouse gas emissions[3]. Certainly, some big players[4] in the construction industry are moving towards proposals which measure and limit embodied carbon in construction and decommissioning. ‘Part Z’ is a scheme with considerable industry support which proposes an amendment to The Building Regulations 2010 (SI 2010/2214) which implements requirements to measure and minimise carbon emissions as part of the whole life cycle of a building[5]. The proposal is aligned with professional statements and guidance from various institutes including RICS (‘Whole life carbon assessment for the built environment’) and BS EN 15978 (‘Sustainability of construction works: Assessment of environmental performance of buildings calculation method’)[6].

The House of Commons Environmental Audit Committee

In response to these developments, the House of Commons Environmental Audit Committee produced a report of its first session on costing carbon in construction in May 2022[7]. The report identifies that the approach to date has been a focus on operational emissions and that current policy does not require the carbon cost of construction to be assessed or controlled. The Committee recognised that, broadly, the industry is willing to progress the issue, and that other countries (and even local authorities in the UK) are already moving towards requiring whole life cycle assessment of construction. Indeed, one of the crucial conclusions reached in the report is ‘[i]f the UK continues to drag its feet on embodied carbon, it will not meet net zero or its carbon budgets’[8]. Various recommendations on whole life cycle assessments are were then made, broadly in line with the Part Z scheme. The Committee recommended:

1. That BEIS undertake monitoring of international policy developments on embodied carbon, with a view to such policy developments being taken into account in decisions on the UK approach.
2. That the Government introduce by December 2023 regulations to mandate whole life carbon assessment for buildings above a gross internal area of 1000 m3 or which create more than 10 dwellings. It was suggested this be established in The Building Regulations.
3. That the Government develop progressively ratcheted carbon targets for the built environment to match the pathway to net zero.
4. That the Government set a clear timetable for the introduction of mandatory whole life carbon assessment and ratcheting of targets by the end of 2022.

Government response

On 30 September 2022 a Government response was published welcoming the Committee report[9]. The response proposes a consultation to commence in 2023. Considering the timescales involved in such consultation and processing amendments to regulations, it is likely the 2023 timescale advanced by the Part Z scheme and adopted by the Committee is unlikely to be met. However, once commenced, the consultation will be an important part of the progress towards management of embedded carbon that industry actors will wish to engage with.

Comment

The importance of carbon emissions in construction is ever-increasing. Whether or not the consultation proposed for 2023 commences then, it is likely that a move to managing whole life cycle carbon emissions will be shortly arrive in any event. Once whole life cycle assessment is mandated with a standardised approach to measurement, it will significantly change approaches to construction and threaten disputes related to failures to meet carbon emission limits. Also, for practitioners involved in the increasing number of ‘greenwashing’ cases, it will be a further area of risk for companies wishing to express positive environmental credentials. With various national policy statements in the planning sphere also currently in draft, whole life cycle assessments may also become an important aspect of consenting development[10]. Thus, those in the construction industry would be well advised to be aware of these changes, the voluntary approach to whole life assessments already being undertaken, and to consider whether to respond to any consultations undertaken by the Government. Once implemented, it is likely these changes will be very significant for the construction industry.