By Jane Anderson (ConstructionLCA, UK)
Although COP26 is focused on actions by state governments, their commitments are often underpinned by industry. The complexity of embodied carbon in buildings depends on regulation and standards, manufacturer compliance, professional engagement and clear methods / data. We must raise embodied carbon literacy and capabilities across the construction industry to expedite readiness for regulation. Several steps are required and some are already underway.
Embodied carbon describes the greenhouse gases (GHGs) associated with the construction materials and processes used to construct and maintain our built environment, and manage it at the end of life. Estimates vary, but globally, it is around 10% of energy related carbon dioxide emissions (UNEP 2020).
The Netherlands, Germany, France, Sweden, Finland and Denmark have regulations to start to measure and limit embodied carbon in buildings. So far, only the Netherlands has limits in force. The other countries are in the process of implementation which will happen over the next few years in order to ensure adequate training and enforcement are in place.
In the UK, there has been growing interest in assessing embodied carbon in recent years, illustrated for example, by the inclusion of embodied carbon benchmarks in the RIBA 2030 Challenge (RIBA 2021). UK Government has also acknowledged embodied carbon with mention of whole life carbon assessment in the Government’s recent Construction Playbook (HM Government 2020). The Welsh Government (2020) has required embodied carbon assessments for all new social housing and the Greater London Authority for larger developments within their jurisdiction (Mayor of London 2021). However, the UK is behind those at the forefront of national initiatives to limit the embodied impacts of construction.
Many construction product manufacturers have committed to achieving net zero by 2050 or before, but there is little recent progress, see Figure 1. Pilots have shown that both steel and cement could be produced without fossil fuels but full-scale production of fossil-free steel is not expected until 2035, and both pilot technologies rely on “green” hydrogen and carbon capture and storage to decarbonise, neither of which are yet viable at the scale required. The wide-scale transformation of existing production plants will be a formidable challenge requiring massive investment.
Regulating the embodied carbon of buildings will focus the attention of architects, engineers, contractors and manufacturers on addressing this impact. Avoiding demolition, considering building form, optimising structure and material efficiency can all make significant savings in embodied carbon, and are likely to reduce costs too. Early in the design process, different material and product options should be reviewed in terms of their embodied carbon impact, when changes are easiest to implement. Contractors must also understand the carbon impacts of changing specifications, and address their materials wastage and energy use.
Regulation at building level should also encourage manufacturers to design more resource efficient products, reduce manufacturing and supply chain impacts and market low impact products using Environmental Product Declarations (EPD). In both Germany and France, the number of EPD rapidly rose with the introduction of their national regulations.
Reviewing the approach in those countries at the forefront of embodied carbon regulation, it is clear that several steps are required. Common steps include:
The UK has already taken steps toward the first three, with the RICS Professional Statement on Whole Life Carbon (RICS 2017), the Inventory of Carbon and Energy (Jones 2019), and the RICS Building Carbon Database (RICS 2019), though all require development to ensure they are ready for use in national regulation.
It is accepted by the construction industry that rapid and significant reductions in GHG emissions are needed. Regulating embodied carbon at the building level would be one way of doing this – by targeting both the way we design and construct and the carbon intensity of products. Although I would wish for much more rapid action to regulate embodied carbon, it is encouraging that the UK’s Net Zero Strategy (HM Government 2021) states: “Government aims to support action in the construction sector by improving reporting on embodied carbon in buildings and infrastructure with a view to exploring a maximum level for new builds in the future.”
My hope is that COP26 will generate commitments from more countries to start regulating embodied carbon in the built environment. The UK must at use this opportunity to learn from the approaches overseas, in order to adopt best practice when regulation comes. We must also ensure the methodology and databases that are essential for regulation are robust and ready, and that embodied carbon literacy and capabilities across the construction industry involving are raised.
GCCA. (2021). GNR Indicator 59cAGWct – World. Gross CO2 emissions - Weighted average excluding CO2 from on-site power generation - Grey and white cementitious products. Global Cement and Concrete Association.
HM Government. (2021). Net Zero Strategy: Build Back Greener.
Mayor of London. (2021). The London Plan: The spatial development strategy for Greater London. London. Greater London Authority.
RIBA. (2021). 2030 Climate Challenge (version 2).
RICS. (2017). Whole life carbon assessment for the built environment. London: Royal Institution of Chartered Surveyors.
RICS. (2019). RICS Building Carbon Database. London: Royal Institution of Chartered Surveyors.
Welsh Government. (2021). Welsh Development Quality Requirements 2021: Creating Beautiful Homes and Places.
World Steel Association. (2021). Our Indicators.
Common sources of occupant dissatisfaction with workspace environments in 600 office buildings
T Parkinson, S Schiavon, J Kim & G Betti
Urban growth in peri- urban, rural and urban areas: Mexico City
G M Cruz-Bello, J M Galeana-Pizaña & S González-Arellano
Overcoming the incumbency and barriers to sustainable cooling
J Lizana, N D Miranda, L Gross, A Mazzone, F Cohen, G Palafox-Alcantar, P Fahr, A Jani, R Renaldi, M Mcculloch & R Khosla
Assessing climate action progress of the City of Toronto
K R Slater, J Ventura, J B Robinson, C Fernandez, S Dutfield & L King
Meeting urban GHG reduction goals with waste diversion: multi-residential buildings
V MacLaren, E Ikiz & E Alfred
Climate action in urban mobility: personal and political transformations
G Hochachka, K G Logan, J Raymond & W Mérida
Transformational climate action at the city scale: comparative South–North perspectives
D Simon, R Bellinson & W Smit
Stretching or conforming? Financing urban climate change adaptation in Copenhagen
S Whittaker & K Jespersen
Embodied carbon emissions in buildings: explanations, interpretations, recommendations
T Lützkendorf & M Balouktsi
Pathways to improving the school stock of England towards net zero
D Godoy-Shimizu, S M Hong, I Korolija, Y Schwartz, A Mavrogianni & D Mumovic
Urban encroachment in ecologically sensitive areas: drivers, impediments and consequences
M H Andreasen, J Agergaard, R Y Kofie, L Møller-Jensen & M Oteng-Ababio
Local decarbonisation opportunities and barriers: UK public procurement legislation
K Sugar, T M Mose, C Nolden, M Davis, N Eyre, A Sanchez-Graells & D Van Der Horst
Canadian cities: climate change action and plans
Y Herbert, A Dale & C Stashok
Energy, emerging technologies and gender in homes [editorial]
Y Strengers, K Gram-Hanssen, K Dahlgren & L Aagaard
Can renewable and smart energy technologies in the home avoid negative consequences for gender, power, and nature-society relations within the domestic sphere? Olufolahan Osunmuyiwa, Helene Ahlborg, Martin Hultman, Kavya Michael and Anna Åberg comment on ‘Masculine roles and practices in homes with photovoltaic systems’ (Mechlenborg & Gram-Hanssen, 2022) – published in a recent Buildings & Cities special issue ‘Energy, Emerging Tech and Gender in Homes’.
The overall outcomes of COP27 (held in Sharm El-Sheikh, Egypt) have been reported by some as disappointing. However, leading city networks such as C40 and ICLEI claim that subnational governments and cities have made a significant breakthrough with the launch of the Sustainable Urban Resilience for the Next Generation initiative (SURGe). This commentary explores how much of a breakthrough this really is.