Sophia Ceneda and Joe Giddings                            SBE0119


Written evidence submitted by Sophia Ceneda and Joe Giddings


Sophia Ceneda, Architect, Sustainability Lead at Glenn Howells Architects, Director of Carbogno Ceneda Architects

Joe Giddings, Architect, Campaigns Coordinator for Architects Climate Action Network, Project Director at the Alliance for Sustainable Building Products


Our motivation for submitting evidence:


We are individual members of the independent and voluntary Architect’s Climate Action Network (ACAN), a mission driven unincorporated organisation established by a group of practising architects in 2019 to rapidly accelerate industry efforts to respond to the climate and ecological emergencies. We have three overarching aims; 1) Rapid decarbonisation of the built environment; 2) Embedding ecological and regenerative principles and 3) Cultural transformation of the design professions to achieve this.


We are part of ACAN’s Embodied Carbon working group focusing primarily on the first aim, Rapid Decarbonisation. Following over a year of research, we launched a report and a campaign earlier this year, outlining how the UK Government could introduce policies and regulations to minimise embodied carbon emissions from construction in the UK. Our submission will focus on these policies, regulations and standards that we think should be adopted.


What role can the planning system, permitted development and building regulations play in delivering a sustainable built environment? How can these policies incentivise developers to use low carbon materials and sustainable design?


The regulatory framework has a very significant role to play in driving reductions in emissions. Over the last decade or so, the Building Regulations have been very effective in reducing emissions from the operational carbon emissions of new buildings, but have so far failed to tackle embodied carbon emissions. Likewise, in London at least, progressive planning policies - often implemented through the GLA’s London Plan and supplementary planning guidance - have been instrumental in the delivery of a sustainable built environment e.g. in areas pertaining to minimum space standards, daylight requirements, amenity space, water management or cycle provision to name only a few. Only recently the GLA has introduced Whole Life Assessment Guidance requiring new building projects known as ‘referral developments’ (i.e. over a certain size) to both report on carbon emissions and provide evidence of reduction in carbon emissions attained through design choices. This can range from avoidance of the demolition of an existing structure, minimising waste through material reuse to material choice such as the use of bio-based materials. The GLA has not set targets as such yet, however we have already received evidence of local authorities that have ‘declared Climate Emergency’ considering the adoption of set targets for any new developments, in effect going beyond the policy currently required by the GLA. 


It is first important to understand that intervention can be taken at different scales as outlined in our report  ‘The Carbon Footprint of Construction’ published earlier this year:[1] The whole building scale and the product/material scale. We refer in particular to a report by Aecom, ‘Options for incorporating embodied carbon into the building standards framework’, which was produced for the CCC in 2019. The report concludes that the introduction of mandatory targets at either scale is likely to be the most effective driver for reductions in embodied carbon. Specifically ACAN’s position is that these targets should be aligned with Science Based Targets.[2] But it is important to note that the two approaches do not preclude each other, and indeed could be complementary. It is also our belief that the introduction of specific policies or regulations at either scale would drive innovation fit for tackling climate change within the built environment .[3]


As senior architects at leading practices and organisations of various sizes, we believe that both approaches should be taken. As architects we work at the whole building scale, and would be comfortable making reductions at this scale, but we also want to know that the materials we specify are low carbon, which in our view would necessitate action from the Government at the product scale. Time and time again, through the delivery of building projects we witness how our efforts to reduce embodied carbon are rejected by clients who revert back to the option they know best, in particular in terms of programme and cost, or as minimum the option required by building regulations, i.e. ‘business as usual’ where carbon emissions are not taken sufficiently into consideration. ‘Business as usual’ does not account for the environmental damage generated in the sector from the extraction of raw materials to manufacturing of building elements to the demolition of existing structures. Which is why we believe the adoption of measures through national regulations and planning is critical.


More detail on both approaches - whole building or product/material scale approach - is set out below, as published in our aforementioned ACAN report but drawn from the Aecom report, with additional input from a 2018 report reviewing carbon reduction approaches at local, regional and national levels  implemented globally and produced by Bionova:[4]



  1. “Whole building life-cycle carbon intensity reductions. Assessment should be targeted at the early phase of the project, through early planning processes, led by policies. Set requirements based on official standards and agreed methodologies. Agree a method for setting carbon cap values and set out incentives for making carbon reductions. Set a clear timeline for how embodied caps for common building types will be introduced, and begin to collect the data to inform these benchmarks. Set compliance requirements and ensure standards are upheld by developing the capacity of Building Control officers.  Progressively tighten targets to drive lifecycle carbon savings.


  1. Elemental (products, materials or building elements) carbon intensity reductions. Identify elements, product types and material substitutions (for new build or refurbishment) with the highest life-cycle carbon values. Set carbon intensity limits for these elements, product types and materials, initially near levels met by incumbent options to support their adoption. Set a trajectory to reduce the limits for each element. Shift to regulation based on whole building carbon intensity targets once the groundwork has been established.”


Every single new building that we design must meet Building Regulations, so if the Government wants to intervene in a way that covers all new buildings, it must legislate for changes to the Building Regulations. That is why we propose the most effective route to driving the necessary reductions in embodied carbon emissions, across the entire lifespan of a building, to be the phased introduction of embodied carbon limits as part of whole-life cycle limits for new buildings, facilitated by the use of low carbon materials incentivised through either the banning of carbon intensive materials or tax relief on use of bio-based materials, and specific policies and regulations to minimise waste e.g. through the introduction of minimum levels of material upcycling and/or a substantial increase in demolition fees when the independent case for demolition cannot be presented on grounds other than safety issues.


As architects we follow projects through stages from feasibility to handover, these are set out by RIBA in their plan of work. More detail is included at each stage, but we believe that assessment of embodied carbon emissions should be required at a number of stages, to capture the changing nature of the design. Across professionals in our industry - incl. architects but also engineers and surveyors, etc. -  there has been an increased awareness of how we can design to help minimise carbon emissions in construction. Many engineers in particular have developed carbon calculating tools (in accordance with BS EN 15978 and based on RICS professional methodology)[5] to that effect, some of which are ‘open source’ to help all members of the design team work towards this shared goal. We might develop design options to reduce carbon emissions through structure, facade and material choices. Using these carbon calculation tools, we provide an estimate of the carbon impact of our design and present the options to our clients accordingly. However as the project develops further, ‘value engineering’ and/or current reluctance of using low carbon materials like engineer timber post-Grenfell results in these options being dismissed on the whole to a ‘business as usual’ design. In case of the use of timber, clients usually refract due to their own insurers’ position - in relation to perceived risk associated with moisture ingress and fire resistance - despite the fact that there are design solutions to using timber in structure with comparable if not better safety conditions than traditional structures made of steel. Furthermore the Committee on Climate Change has estimated that the carbon ‘savings’ from building 270,000 homes in timber would be 3M tonnes per year demonstrating that the use of timber in construction is one of the most effective ways to reduce carbon emissions.


In a recent correspondence with ACAN dated 7 May 2021, in response to our demand to regulate carbon emissions in the UK through British Regulations, the government has indicated it is looking at low carbon materials but we feel this is not going far enough. Lord Greenhalgh, Minister of State for Building Safety, Fire and Communities, wrote on behalf of the Ministry of Housing, Communities and Local Government:


The Department is (...) carrying out wider work to consider the future of energy efficient and low carbon buildings, looking beyond the scope of Building Regulations and including the role of low-carbon materials, such as timber, in delivering low-carbon construction. DEFRA’s forthcoming Tree Action Plan will also outline the next steps Government is taking to support the use of timber, where safe to do so and with a focus on low-rise homes.’


We feel that it is crucial that Building Regulations are addressed as part of the national solutions and whilst we are very much looking forward to seeing DEFRA’s Tree Action Plan, the use of timber should not be limited to low-rise homes but also encouraged if not mandated in medium and high-rise buildings of all types including residential that deliver thousands of homes every year as in the case in London. A well-publicised example of such policy from France has been the requirement that all buildings over 8 storeys to be delivered as part of the 2024 Paris Olympics be made of timber; in addition to the requirement for all new public buildings to use at least 50% in their construction.


The case for regulating embodied carbon is not limited to the use of timber. As architects we might also suggest to retain an existing structure - providing it is safe - for which we can find an adequate design solution which would save tonnes of carbon emissions and minimise a huge amount of waste too as waste from demolition and construction is said to represent the largest single waste stream in many countries. Retaining existing structures - depending on structure size and condition - can typically result in up to 60% of carbon savings as the construction of a new structure in a building constitutes the bulk of carbon emissions.[6] Yet the systematic approach would be to demolish for a new flagship building instead. Whilst there is clear evidence that largest developers are embracing low carbon (or ‘net zero’) construction, this is not always the case and our experience demonstrates that for most construction companies it might take regulatory and/or planning incentives to make that decision.  In a recent article by British Land Project Director Charles Horne, commenting on the completion of a large office building at 100 Liverpool Street, stated: 


‘As a construction professional, if you’d asked me five years ago, “Do you want to leave that structure there or take it down?”, I would always have said, “Take it down,” because to build from new is easy; to build with existing is more complicated. Today, cutting carbon is one of the highest items on the agenda for British Land projects, along with profitability’.[7]


Elsewhere in the same article, Charles Horne writes:


Some of this is due to fortunate opportunities – it won’t be possible to achieve this on every project in the coming years (...).  The biggest impact on embodied carbon at 100 Liverpool Street came from retaining 50% of the existing structure. Here, sustainability went hand in hand with the commercial case. Looking at the four project fundamentals – cost, programme, value and risk – retaining the structure benefited all these, while dramatically cutting embodied carbon.’


This is currently an exception rather than the rule. Without incentives and/or punitive measures to make the commercial case for low carbon design and low carbon material uses, companies will always look at the commercial case prior to the environmental case. Due to this lack of regulations, the cost of construction to the environment and climate change remains unaccounted for.


So we think that Whole Life-cycle Carbon Assessments should be mandated, and reported - as is now the case for all public works projects and programmes, as stipulated in the Government’s Construction Playbook since December 2020[8] - within Building Regulations, National Planning Policy Framework & Local Planning Policy. This would bring embodied carbon emissions into the UK’s building standards framework and in-line with considerations of operational energy use that already exist.


International & Municipal Examples of Policy


In the last few years alone,  a number of countries and cities have introduced policies and regulations to tackle the embodied carbon of new buildings and construction to ensure that an industry that greatly contributes to the release of carbon emissions in the atmosphere can become part of the shift towards a low carbon economy whilst meeting their commitments under The Paris Agreement. These different approaches taken internationally can be found in the resources listed below. We also present a small selection of these measures as outline in our own ACAN report - outlining their benefits and shortcomings - and which we believe can shape an approach suitable to the UK. Further readings on policies and regulations can also be found in the report by the Carbon Neutral Cities Alliance/OneClick LCA ‘City Framework For Dramatically Reducing Embodied Carbon - 52 detailed policies to reduce embodied carbon’.[9]


Since 2013 in The Netherlands, all new residential and office buildings in excess of 100m2 must have their embodied carbon emissions calculated and reported, with limits brought in 2018 and tightened 2021. Further reading can be found;

        On the Netherlands Enterprise Agency website (in Dutch) accessed via this link

        In the Aecom report for the CCC, ‘Options for incorporating embodied carbon into the building standards framework’, accessed via this link


In France, a new environmental regulation for buildings has been announced this year (2021), referred to as ‘RE2020’, which will require whole life-cycle carbon assessments to be carried out for all new development. Limits will be placed on whole life-cycle carbon emissions from 2024, being reduced first in 2027 and again in 2030, at which point all new buildings in France will be required to have 58% lower embodied carbon emissions over today’s baseline. Further reading can be found;

        In a 2021 publication from the Ministère de la Transition Ecologique, ‘RE2020: Éco-construire pour le confort de tous’ (in French), accessed via this link

        Summarised in an article on the French website Construction 21, accessed via this link

        Summarised in English in our ACAN report ‘The Carbon Footprint of Construction’, accessed via this link


In Finland all new buildings will be required to measure whole life-cycle carbon emissions and meet strict limit values from 2025. This is summarised in an article in English, from two of the architects and Finnish Government employees responsible for the new law, Matti Kuittinen & Tarja Hakkinen, ‘Reduced Carbon Footprints of Buildings: new Finnish Standards and Assessments’ accessed via this link.


In Denmark all new buildings will be required to measure whole life-cycle carbon emissions from 2023, with limits brought in at the same time for large developments, and limits for all buildings brought in from 2025. Further reading can be found;

        On the Danish Housing & Planning Agency website (in Danish), accessed via this link

        This was summarised in an article on page 14 of issue 37 of the Passivehouse Plus magazine, accessed via this link (with the below table extracted for ease of reference):

In the United States of America, there are numerous efforts being proposed to address embodied carbon at the federal level, but these are yet to be set. Multiple initiatives have however been introduced across 10 states, the first of which to have been signed into law was the Buy Clean California Act (BCCA),[10] which specifically focuses on addressing the Global Warming Potential (GWP) of embodied carbon through regulating procurement to only those that have a GWP below targets set by the State.[11] It is limited only to infrastructure projects, but this can include public buildings.   Further reading can be found;

        On the Carbon Leadership Forum’s ‘Tracking Federal Action’ page via this link and via their policy toolkit page via this link

        Summarised in our ACAN report ‘The Carbon Footprint of Construction’, accessed via this link


It is our position that these limited examples already implemented demonstrate both a strong case for using planning policies at local level and Building Regulations at national level; and a breadth of measures available to account for and reduce the impact of embodied carbon emissions in the environment generated by the construction sector.


May 2021

[1] The Carbon Footprint of Construction, 2021, Architects Climate Action Network, available via:

[2] Science Based Targets represent the scientific community’s understanding of what the global ecosystem can tolerate without triggering climatic tipping points that would result in catastrophic global changes to our ecosphere.

[3] Aecom, for the Committee on Climate Change, (2019) “Options for incorporating embodied and sequestered carbon into the building standards framework

[4] Bionova Ltd, (2018) “The Embodied Carbon Review. Embodied Carbon Reduction in 100+ Regulations & Rating Systems Globally”

[5] The British Standards Institution (2011); BS EN 15978:2011 Sustainability of construction works - Assessment of environmental performance of buildings and RICS, (2017); “Whole life carbon assessment for the built environment” Link


[6] See Dave Cheschire, Mark Burton, ‘The carbon and business case for choosing refurbishment over new build’ at (last accessed on 14 May 202).

[7] ‘Lessons on net zero offices from 100 Liverpool Street’, Building, 7 April 2021 at (last checked on 10 May 2021)

[8] HM Government, ‘The Construction Playbook. Government guidance on sourcing and contracting public works projects and programmes’, Version 1.0, December 2020.

[9] CNCA/OneClick LCA at (last checked on 14 May 2021)

[10] ‘Buy Clean California Act’ [online] Department of General Services. Available at: Link [Accessed 13th Dec. 2020]

[11] Washington State has also since enacted a similar bill: International Living Future Institute (2019) “Embodied carbon in new construction guidanceLink