Seb Laan Lomas and Rachael Owens                            SBE00095


Written evidence submitted by Seb Laan Lomas and Rachael Owens


Rachael Owens is an Architect at Buckley Gray Yeoman, and specialises in the reuse and refurbishment of existing buildings, finding the potential in what is undervalued, unloved and overlooked. Rachael is driving the sustainability agenda at BGY and is calling for embodied carbon to be taken seriously within the built environment sector.

Seb Laan Lomas is an Architect, Certified Passivhaus Designer, and Head of Sustainability at Hopkins Architects, with a postgraduate degree in environmental design and energy performance and experience delivering low-impact, long-lasting, high-performance buildings.


We are individual members of the independent and voluntary Architects Climate Action Network, 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 the Embodied Carbon working group focusing primarily on the first aim, Rapid Decarbonisation. Following almost 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 believe need to be adopted.


This submission is formatted in response to the Environmental Audit Committee’s first question: To what extent have the Climate Change Committee’s recommendations on decarbonising the structural fabric of new homes been met? - but expands to address the other interrelated questions.





0.1 Executive Summary


        There is industry consensus that the significant climate impacts and associated embodied carbon emissions from construction and construction materials need to, and can; be measured, understood, reported, and reduced.

        There are international examples of comparative countries having developed and implemented embodied carbon regulations at national and city levels.

        There is significant research to demonstrate that these regulations and policies can generate significant opportunities and co-benefits for the economy through green job creation and increased delivery of new homes, and society through the retention and improvement of existing built environments.

        We believe that the continued failure to introduce embodied carbon regulations for the construction sector will pose a significant barrier to the UK’s successful pathway to its legal obligations for decarbonisation.


0.2 Key Recommendations:

        The Government should adopt the RICS “Whole Life Carbon Assessment for the Built Environment” professional statement as the nationally agreed methodology for measuring embodied carbon emissions and urgently undertake any work it perceives as necessary to bolster and develop this standard to enable regulation on whole-life carbon emissions.

        A new part of the Building Regulations tackling embodied carbon emissions should be phased in, with mandatory reporting of whole life carbon emissions coming first in 2022, followed by the introduction of limit values in 2025, which must then be reduced over time.

        Policy SI 2 within the Greater London Authority’s new London Plan for the measurement and reporting of whole life carbon emissions should be incorporated within national and local planning requirements as a priority.

        The Government should mandate Environmental Product Declarations to be submitted from construction material suppliers above a certain size, with trade bodies assisting smaller organisations, to a freely accessible UK database.

        The Government should introduce planning policy including revised demolition permission fees, mandatory planning permission for demolition, revised VAT rates, improved public procurement rules, and reversed permitted development rights in order to incentivise and drive the retention and retrofit of existing buildings to become the norm in the UK, and to deter demolition.




1.1              We  refer to two key documents produced by the Climate Change Committee (CCC): the ‘6th Carbon budget’ and ‘UK housing: Fit for the future?’, we also make reference to ‘Wood in Construction in the UK: An Analysis of Carbon Abatement Potential’ produced by the BioComposites Centre for the CCC. The 6th Carbon budget sets out a ‘balanced pathway’ to reach the Government’s target of net zero greenhouse gas emissions by 2050, which identifies emissions reductions required in each sector and provides recommendations to achieve these reductions. ‘UK housing: Fit for the future?’ also identifies routes to reduce greenhouse gas emissions from housing, in order to meet the UK Government’s climate objectives. We will consider specifically the recommendations on Embodied Carbon emissions, and the carbon footprint of construction. Direct quotes from the CCC’s reports are given in italics.


1.2              Within the response the following terms are used, the authors define these terms as follows:

Whole-life carbon (WLC): the sum total of all asset related greenhouse gas emissions, both operational and embodied over the whole life cycle of the asset, including construction, maintenance, operation, demolition and future reuse or recycling.

Embodied carbon: the greenhouse gas emissions associated with the materials and construction processes throughout the whole life cycle of an asset, including: material extraction, transport to manufacturer, manufacture, transport to site, construction, maintenance, repair, replacement, refurbishment, deconstruction, transport to end of life facilities, processing and disposal.




2.1              The 6th Carbon budget and accompanying Policy Report acknowledge that there are few policies in place to “improve resource efficiency and incentivise material substitution within construction of assets such as buildings and infrastructure” and that the Government must rapidly develop policy, as part of a clear strategic vision, to ensure that it pays for companies to implement measures that reduce embodied carbon emissions. The CCC report ‘UK housing: Fit for the future?’ specifically recommends “standards such as whole-life carbon intensity targets in Building Regulations,” and a large part of the required policy vision will be the introduction of mandatory disclosure of whole-life carbon emissions for buildings and infrastructure and a subsequent “mandatory minimum whole-life carbon standard…which strengthens over time, with differentiated targets by function and usage.”


2.2              Currently the national government has made no public progress towards this recommendation, despite making progress to review regulation of operational energy through the Future Building / Homes Standard consultations. At a local level cities such as London and Manchester have started to introduce planning policy on whole-life carbon emissions. This local action shows awareness of the problem, political willingness to address it, and acknowledgement of the industry’s ability to begin tackling it. However, to tackle this significant source of emissions nation-wide, the industry requires the UK Government to set out what the next steps will be towards the introduction of policy to limit whole-life carbon emissions across all works for new and existing buildings. Clarity of the policies and regulations will provide the confidence to those investing in tackling this issue, give consistency for those reporting, and establish the scope of guidance and training required across the Industry.


2.3              In order to increase professional knowledge and capability, a timeline should be set out for the adoption of whole building carbon calculations as a mandatory requirement.


2.4              ACAN’s report ‘The Carbon Footprint of Construction’[1] sets out clear timeline recommendations, based on cross-industry consultation and international precedents. This report recommends the phased introduction of regulation, with mandatory reporting of WLC emissions coming first in 2022, followed by the introduction of limit values in 2025, which will then be reduced over time. This will allow data to be gathered nationally, and benchmarks set over a three year period, and provide time and incentive for the industry to up-skill. The timeline set out is therefore in line with the CCC recommendation to “Undertake low-regrets action to support the assessment and benchmarking of whole-life carbon in buildings with a view to informing the future policy framework.” Mandatory reporting of WLC emissions is one of the measures urgently needed to support the CCC’s recommendation to drive resource efficiency, reduce material use and optimised building design to “reduce emissions by 5 MtCO2e per year in 2035.”


2.5              Building regulations provide the best tool for limiting embodied carbon emissions at a national level, as these are applied to all construction projects for new and existing buildings, and will not allow schemes that do not require planning permission to be left unregulated. There are a number of options for incorporating embodied carbon into the building regulations, set out in ACAN’s report, which recommends the creation of a new ‘Part Z.’ Refer to p26 of the report for further details.1




3.1              In order to introduce regulation on whole-life carbon emissions the 6th carbon budget recommends that the Government must “work with industry to agree a standard for the ‘whole-life’ carbon footprint of buildings and infrastructure”.


3.2              It is important for the Committee to acknowledge that the majority of the work to define this standard has already been carried out: in 2011 the framework by which a building’s environmental footprint, over its lifetime, should be calculated and communicated using a Life Cycle Assessment was set out by the British Standard BS EN 15978:2011.76.[2] This standard is applicable to all new and refurbishment building projects, and provides the standard methodology that can be used to cover the building’s operational and embodied carbon emissions. In 2017 the RICS defined the scope and methodology for carrying out WLCA in accordance with this BS EN with the publication of “Whole Life Carbon Assessment for the Built Environment.”[3] Contrary to views by some that insufficient guidance exists to tackle the challenge of embodied carbon in construction , this document is already widely used by professionals within the industry, and is the basis for many WLC calculation tools used by designers already in pioneering instances, such as H\B:ERT, PHRibbon and ECCOlab. Using this document professionals can understand, consistently measure and report the carbon impact of construction projects, allowing results to be compared with one another.


3.3              In 2019 & 2020, RIBA[4] and IStructE[5] published embodied and whole life carbon assessment guidance for architects and structural engineers respectively. At the start of 2021 CIBSE published guidance for its members on the embodied carbon in building services.[6] These documents complement one another and are all based on the British Standard BS EN 15978:2011. These documents are all under cyclical review from industry experts show a pan-industry acknowledgment, readiness, and competency..


3.4              The next step is for The Government to adopt the RICS “Whole Life Carbon Assessment for the Built Environment” professional statement as the nationally agreed methodology for measuring embodied carbon emissions, as set out by BS EN 15978. The Government should have faith in this British Standard as the underlying European Standard is widely used. If, however, The Government perceives this British Standards inadequate, they must urgently take inspiration from governments around the world, who have demonstrated leadership to develop methodologies and standards applicable to their national circumstances, and work with industry specialists to provide the industry with a Standard to rapidly enable regulation on whole-life carbon emissions.


3.5              The ‘UK housing: Fit for the future?’ report recommends “Action to support the assessment and benchmarking of whole-life carbon over the next 3-5 years, with a view to informing a decision on a future mandatory framework” currently little action has been taken, but the steps set out above can address this recommendation.




4.1              For professionals to calculate the whole-life carbon emissions of their projects, there must be agreement and information on the carbon footprint of building products.  BS EN 15804:2012[7] sets out the standard methodology by which the environmental impact of products should be measured and reported. This standard defines the format of Environmental Product Declarations (EPD), documents that communicate this information to industry professionals. There are international databases of available EPDs across supply chains, such as EcoPlatform,[8] and as of 2021, there are over 10,000 compliant and independently verified EPDs. 


4.2              A briefing paper by the Alliance for Sustainable Building Products (ASBP)[9] recently surveyed that there are only 360 EPDs using this BS EN for UK-produced products across 60 manufacturers. Research by Life Cycle Assessment expert Jane Anderson[10] demonstrates that our supply-side is behind the curve of this important topic in contrast to other countries, with the highest number of EPDs available for French products where Whole Life Carbon regulation already exists.




5.1              Both the ‘Sixth Carbon Budget’ and ‘UK housing: Fit for the future?’ make specific recommendations on reducing the carbon impact of construction at the product / material level. The ‘balanced pathway’ relies on “partial substitution of clinker in cement and the use of wood in construction… increas(ing) steadily over the period to 2050.” Although the concrete industry has gone some way to reduce the embodied carbon of concrete using additives such as Fly Ash and GGBS/GBFS to replace cement, the carbon footprint of concrete remains high, and the global supply of these additives is finite. Fly Ash is a by-product of coal-fired power plants, and as the UK’s reliance on coal power declines so will UK supplies. GBFS is a by-product of steel produced with Basic Oxygen Furnaces and as the industry moves towards lower emission steel production using Electric Arc Furnaces, national supply of GBFS will also decline,[11] Therefore substituting the use of concrete where viable is also required to ensure the construction industry decarbonises in line with national targets.


5.2              The use of structural timber is acknowledged to offer numerous benefits; increased construction speed, reduced constructional dust and noise pollution, locking away carbon for long periods through sequestration, investment in forestry and green jobs, reduced foundations, and offering circular opportunities. Bangor University found that “At the individual building level, the reduction in embodied emissions for substituting timber frame for masonry is approx. 20%. A greater reduction (~60%) is seen for CLT and concrete structures.”[12] However, rather than becoming the material of choice for construction in many scenarios it has been discouraged and prevented by The Government’s combustible cladding ban, with developers and insurers losing confidence in the material.  If The Government is to meet the CCC’s recommendations to “support a substantial increase in the use of wood in construction.” it needs to introduce specific policy to support the appropriate use of safe timber, alongside the work and testing that the STA, TDUK, and leading developers are currently undertaking to provide sufficient acceptable test data of the fire performance of modern mass timber structures.


5.3              At the highest level, there are two overall strategies to reduce carbon emissions by material use:

        Material substitution: replacing a high embodied carbon material with a lower carbon material in a construction project, such as replacing steel with wood.

        Material improvement: reducing the embodied carbon of a specific material or product, by, for example, using renewable energy sources in production, or reducing the proportion of cement in concrete.


5.4              To our knowledge and as informed by our daily practice, the Government has made some progress to regulate the steel and cement industries in an effort to lower emission, however policy must go much further to incentivise these practices. ACAN’s report sets out a number of policy recommendations to achieve this in ‘The Carbon Footprint of Construction,’[13].These policies are informed by work from the Carbon Neutral Cities Alliance report[14], and summarised specifically for the UK context for specifically reducing emissions at a product / material level:

        Carbon limits for key materials

        Bio-based materials for designated areas of development

        Limiting the environmental damage from concrete                                         

        Salvaged, reused or recycled material minimums


6.1              The 6th Carbon Budget identifies that emission reduction measures can “support and create jobs, especially in regions with reliance on industrial jobs. Prompt award of existing funding can help the recovery” through policy. The Government has made little progress toward the introduction of policy to decarbonise construction, and should urgently act to introduce policies, to cut emissions and seize the opportunity of creating green jobs.


6.2              A report by the EAC published this year recognises the link between embodied carbon targets and the creation of green jobs, with the recommendation “that the Government introduce embodied carbon targets for the construction of new homes, so as to increase demand for low carbon materials, thereby stimulating growth in low- emission manufacturing of traditional, local materials and promoting the use of new low carbon materials.”[15] - a recommendation we welcome and hope The Government adopts as a priority.


6.3              Policy to promote the use of timber in construction would support the creation of green jobs in the UK’s sustainably managed timber and bio-based materials industry. This has been explored in the CCC’s report on the UK’s bioeconomy[16] and by the Green Finance Institute[17] with further benefits to the UK’s housing market highlighted by the All Party Parliamentary Group for the Timber Industries in 2019.[18]


6.4              The Government should also introduce policy to set minimum limits for salvaged, reused or recycled material, for example, with public projects required to meet minimum levels. This type of policy would boost the construction materials recycling industry. Analysis by WRAP has estimated that 500,000 jobs could be created in the UK through the transition to a more resource efficient circular economy.[19] Policy to limit the whole life carbon emissions of buildings and infrastructure would help to promote locally made products, as emissions from transportation, which are required to be included within a WLC assessment, are likely to be lower than for imported products. Policy that supports the use of EPDs can also lead to innovation and product development, as less destructive methods are sought to produce and use materials and products (e.g. designing for deconstruction and re-use), and would “develop the capacity of skills and supply chains.”


6.5              In ‘UK housing: Fit for the future?’ the CCC recommends “Minimising the need for new build (e.g. through measures to reduce under occupation in existing buildings) could also play a role in delivering carbon savings where those buildings can be decarbonised cost-effectively.” Currently the UK’s VAT rules incentivise demolition and new build development, as developers are required to pay 20% VAT on refurbishment, retrofit and extension projects, whereas new build is zero rated for VAT. In our own professional experience we have seen this application of VAT alone resulting in buildings being ear-marked for demolition when their owners had initially sought to refurbish them. In London alone there are over 100 council and housing association estates under threat of demolition[20] and this demolition is set to cause the loss of over 13,500 council homes, if currently approved projects are completed.[21]


6.6              The UK can learn international examples, such as Lacaton & Vassal’s work in France. The practice, a recent recipient of the Pritzker Prize, have completed schemes such as la Tour Bois le Prêtre in Paris, where an existing 1960s apartment block was carefully refurbished and extended to provide residents with extended living space, balconies while thermally upgrading the block, and keeping residents in place throughout the construction programme.[22] The Government must introduce policy to require retention and retrofit of existing buildings becomes the norm in the UK, rather than demolition, such as to:


        Increase demolition permission fees[23]

        Require planning permission for building demolition23

        Cut the rate of VAT on refurbishment projects to the same or less than the rate on new-build projects[24]

        Ensure that all publicly funded projects consider refurbishment and retention first

        Reverse permitted development rights that allow vacant commercial buildings to be demolished to create new residential units, without full planning permission


6.7              We believe that it is through these important collective actions, regulations, and policies, that the significant climate impacts and carbon emissions caused by the construction industry could be rapidly and significantly reduced, to assist the UK’s essential decarbonisation, whilst contributing to economic and societal progress.


May 2021

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

[2] The British Standards Institution (2011); BS EN 15978:2011 Sustainability of construction works - Assessment of environmental performance of buildings - Calculation method

[3] RICS, (2017); “Whole life carbon assessment for the built environment” Link

[4] RIBA, (2019); “Embodied and Whole Life Carbon Assessment for Architects.” Link

[5] IStructE, (2020); “How to calculate embodied carbon” Link

[6] CIBSE, (2021); “TM65: Embodied carbon in building services: A calculation methodology Link

[7] BS EN 15804:2012+A2:2019 (2019) “Sustainability of construction works. Environmental product declarations. Core rules for the product category of construction productsLink

[8] ECO-Platform, (2021); EPD Database Link 

[9] ASPB, (2021);”Environmental Product Declarations (EPD) for UK products”  Link

[10] Anderson, J (2021) “ConstructionLCALink

[11] BEIS (2017) “Fly ash and blast furnace slag for cement manufacturing” Link

[12] The BioComposites Centre (2019) “Wood in Construction in the UK: An Analysis of Carbon Abatement Potential” Link

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

[14] Carbon Neutral Cities Alliance & Bionova Ltd (2020) “City Policy Framework for Dramatically Reducing Embodied Carbon” Link

[15] House of Commons Environmental Audit Committee (2021) “Growing back better: putting nature and net zero at the heart of the economic recovery” Link

[16] Committee on Climate Change (2018) “Biomass in a low carbon economy

[17] Green finance Institute (2020) “Stimulus actions for a greener and more resilient property sector Link

[18] All Party Parliamentary Group for the Timber Industries (2019), “How the timber industries can help solve the housing crisis

[19] Julian Morgan & Peter Mitchell, for Wrap & Green Alliance (2015) “Employment and the circular economy; Job creation in a more resource efficient Britain”.

[20] Estate Watch (2021) “Estates under threat” Link

[21] Sian Berry (2021) “Social housing loss hits 13,500” Link

[22] Lacaton & Vassal (2011) la Tour Bois le Prêtre Link

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

[24] Architects Journal (2019) “Introducing RetroFirstLink