Planning and climate change guidance: research report issue 3

4 Whole Life Carbon Assessment

4.1 Background

4.1.1. NPF4 Policy 2a applies to all development proposals and requires that they will be “sited and designed to minimise lifecycle carbon emissions as far as possible” to aid the achievement of Scotland’s net zero future. Assessing the whole life carbon emissions of a development at the earliest stages of the planning process is crucial to enable appropriate decision making and ensure alignment with net zero policy.

4.1.2. This section outlines available information sources, tools, methods, and approaches that can be applied in the planning process to assess whole life carbon of a variety of development types. This section also provides a view as to the pros and cons of each and an indication as to which is considered best practice. It should be noted that this section is not intended to be exhaustive and includes examples of what is currently being used and could be considered best practice in Scotland and the UK.

4.1.3. Approaches being used as the ‘status quo’ and feedback on their relative usefulness, identified from engagement with key stakeholders with roles throughout the planning process, is summarised in Section 8 of this report.

4.2 Information Sources

4.2.1. There are several authoritative information sources that can be used to inform best practice life cycle carbon assessment. This section summarises three freely available databases which can be used to assess whole life carbon of various development types.

DESNZ Greenhouse Gas Reporting: Conversion Factors

4.2.2. The Department for Energy Security and Net Zero (DESNZ) conversion factors^[5] are a set of conversion factors that can be used by UK and international organisations to calculate carbon emissions across a wide range of activities categorised by Scope 1, 2 and 3.

4.2.3. The factors are divided into three sections:

• Scope 1 (direct emissions), e.g. fuel consumption.
• Scope 2 (indirect energy emissions), e.g. electricity consumption.
• Scope 3 (indirect supply chain emissions), e.g. waste disposal, business travel, etc.

4.2.4. The DESNZ conversion factors are commonly used across various sectors in the UK as the database is accessible, free, and contains well developed factors that are updated annually by the UK Government. The factors relate to organisational emissions rather than whole life carbon emissions associated with a specific built asset or infrastructure activity or product. Therefore, the DESNZ database can be used to assess the operational emissions relevant to a specific asset only and should be used in conjunction with another database that holds factors for the other life cycle stages to provide an appropriate view of the related whole life carbon emissions.

Inventory of Carbon and Energy Database

4.2.5. The Inventory of Carbon and Energy (ICE) database (Version 3)^[6] is a comprehensive resource developed to quantify the embodied energy and carbon emissions associated with various materials and processes throughout their life cycles. It was created by researchers at the University of Bath to provide detailed and reliable data on the carbon and energy impact of a diverse range of materials and activities.

4.2.6. The database encompasses a wide range of materials, products, and processes, offering information on the energy and carbon inputs and outputs at each stage of their life cycle. It includes data from across the life cycle including related to raw material extraction, manufacturing, transportation, use, and disposal.

4.2.7. The ICE database is freely available and is widely utilised for life cycle assessment (LCA) studies, allowing researchers, policymakers, and industries to evaluate and compare the environmental impacts of different materials and processes. It aids in making informed decisions to reduce carbon emissions and energy consumption at the earliest stage in the development process.

4.2.8. Like any database, the ICE database may have limitations in terms of completeness and representativeness of data. Some specific materials or processes may not be adequately covered, and the database may require regular updates to accurately reflect the changing landscape of life cycle assessment. Additionally, effective utilisation of the database may require a certain level of expertise in life cycle assessment, potentially limiting accessibility for those without specialised knowledge.

4.2.9. However, the benefits of utilising the ICE database are clear given it is a comprehensive and reliable resource that can be used to assess the whole life carbon associated with materials and processes throughout their life cycles. Thus providing a reliable database that can be used to inform decision making around many types of development in the built environment.

Built Environment Carbon Database

4.2.10. The Built Environment Carbon Database (BECD)^[7] is a free-to-access database that launched in 2023. It was developed in partnership with organisations across the built environment with the aim to become the main source of WLC estimating and benchmarking for UK developments. The BECD collects and supplies both product-level and entity-level data to the industry through its own portal, and through interacting with existing databases and software solutions.

4.2.11. The first section of the database contains data at entity level, provides benchmark-type data points to support the feasibility, early design, and end of life stages of project development. It is suitable for buildings and infrastructure including transport, energy systems, communications, water, waste, and ecosystem support services, and is aligned with the EN15978^[8] and EN17472^[9] standards. For each type of entity, users can quantify and report WLC assessed at the early design, detailed design, and post-completion project stage. Each set of carbon figures are subdivided into entity elements (e.g. structure, finishes, etc.) as well as life cycle stages. Users can generate custom benchmarks to compare their own projects against relevant benchmarks in order to assess their options and inform decision making.

4.2.12. The second section of the database contains data at product level to support the evolving and detailed design, construction, and operational stages of a project, according to the EN15804 standard. Classification is available by object type and enables users to generate the typical whole life carbon emissions associated with the development. Product level data allows for comparison between material options and enables the provision for reliable entity-level carbon assessments.

4.2.13. The BECD can be used to estimate the carbon emissions of a building or infrastructure project, and to compare the carbon impact of different materials and construction methods. It can also be used to benchmark the carbon performance of a project against industry standards. The BECD’s data can be accessed through its own portal or by interacting with existing databases and software solutions. It also has an emerging asset library so would be useful at the very early stages of planning, for example when considering options for a specific type of building.

4.2.14. Due to the robustness of the approach to building the database and support from major professional institutions, the BECD is envisioned to become the main source of carbon estimating and benchmarking for the UK construction sector and a practical instrument to support the decarbonisation of the built environment as a whole.

Carbon Storage and Sequestration by Habitat

4.2.15. It may also be necessary to estimate the carbon benefits of a development, e.g. associated with tree planting or other nature based ‘blue/green infrastructure’. In 2021, Natural England published research into carbon storage and sequestration rates of different semi-natural habitats with an indication of the range of values and associated degrees of confidence^[10]. In the absence of a direct equivalent report in Scotland at the time of writing, it is reasonable to use the information contained within this report to estimate habitat-based carbon benefits.

4.3 Tools and Models

4.3.1. There are several resources that can be used to assess whole life carbon emissions from infrastructure and the built environment in Scotland to inform the planning process. The focus in this section is on tools which hold carbon data and can be used to calculate carbon emissions, and models which can present scenarios and analyse the data. The paragraphs below provide further detail on several tools currently in use across the built environment, using suitably robust data to inform whole life carbon assessments. Some of the identified resources are both tools and models in that they can both calculate the carbon emissions and present scenarios and analyse the carbon data further.

4.3.2. Most of the identified tools/models are commercially available through a paid subscription, but some are free to use for specific users; including the RSSB Rail Carbon Tool which is free to use within the rail industry. One Click Planetary, a result of collaboration between One Click LCA and partners including the UK Green Building Council, is a freely available tool for benchmarking cradle-to-gate embodied carbon. This tool is ‘IMPACT’ compliant which Zero Waste Scotland considers will enhance consistency and accuracy of results^[11].

4.3.3. Some tools provide the ability for users to update tool databases (e.g. SimaPro, Moata Carbon Portal, Supply Chain Sustainability School Carbon Calculator, RSSB Rail Carbon Tool and Umberto). Other tools, such as OneClick LCA and Cerclos eTool, allow users to update tool databases only with vender support with a commercial arrangement.

4.3.4. OneClick Planetary and OneClick LCA provide access to a global library of Environmental Project Declarations (EPD), as well as the ability to create specific EPDs for products not included in the library, which would provide useful for developers who wish to ensure the most accurate picture of their development’s carbon impact. OpenLCA, Umberto, and Spera specify the ability to support the creation of EPDs but does not specify the provision of access to a library of EPDs. The Cerclos eTool provides access to a library of EPDs but does not specify the ability to support the creation of EPDs.

4.3.5. Other identified features include the ability to provide automated reporting and graphics, to easily inform early stage decision making and to evidence WLC emission minimisation within the planning process. OneClick Planetary, OneClick LCA, Cerclos eTool, SimaPro, RSSB Rail Carbon Tool, Umberto and Sphera all have the capability to do this type of reporting.

4.3.6. Additionally, several of the assessed tools can generate and compare WLCA scenarios, including OneClick Planetary, OneClick LCA, SimaPro, Umberto and Sphera. This would allow developers to inform the siting and design of development proposals to ensure WLC emissions were minimised as far as possible in alignment with NPF4 Policy 2a). Open LCA, SimaPro and RSSB Rail Carbon Too also have the capability to quantify life cycle costs.

4.3.7. An indication as to which tools are being used most often by developers to quantify whole life carbon emissions is summarised in Section 8 of this report.

4.4 Methods and Approaches

4.4.1. Authoritative approaches to managing whole life carbon emissions from built environment projects within the UK are covered in this section, including an overview of best practice methods and guidance documents used to inform whole life carbon emissions assessments.

PAS 2080:2023 Carbon Management in Buildings and Infrastructure

4.4.2. PAS 2080:2023^[12] is a best practice approach for managing carbon in buildings and infrastructure. The standard covers the whole value chain of the project and aims to reduce carbon and add value through intelligent design, construction, and use. It was developed by a key group of relevant professional bodies and technical authors and is aimed for use by anyone involved in the delivery of buildings and infrastructure including:

• Infrastructure asset owners and managers
• Designers and architects
• Constructors
• Material and product suppliers
• Regulators, financiers and governments

4.4.3. PAS 2080 emphasises the importance of all parties involved across the value chain working collaboratively towards a common carbon reduction goal and the achievement of the following outcomes:

• More collaborative ways of working that promote innovation, delivering benefit to society and communities served by new buildings and economic infrastructure;
• Effective carbon management in buildings and infrastructure that makes an important contribution to tackling climate change and leaves a positive legacy for future generations; and,
• The delivery of more sustainable solutions, at lower cost, that will enhance the reputation of the buildings and infrastructure industry, generating pride for those who work in it and attracting new people and skills.

4.4.4. PAS 2080 enables consistency in the approach stakeholders take to manage whole life carbon in buildings and infrastructure, and across supply chains, in line with the net zero carbon transition. It can be applied to asset, network, or system level programmes of work. Buildings and infrastructure providers can become PAS 2080 certified, which demonstrates adherence to industry best practice and commitment to lead sector climate action. Being PAS 2080 certified also provides a competitive advantage. Major infrastructure providers in the UK are now required to be PAS 2080 certified, which means that many of their suppliers also need to demonstrate compliance with PAS 2080 guidance.

4.4.5. PAS 2080 has received accolades for being the best practice approach to assess whole life carbon of developments within the built environment and is being utilised more often by developers across in the UK.

4.4.6. Aligning to PAS 2080 has also been signalled by government agencies in the UK. For example, in the regulated electricity industry, there is expectation from Ofgem for network operators to improve whole life carbon reporting and to align to PAS 2080 for all major infrastructure projects across the transmission and distribution networks^[13]. Additionally, the UK Department for Transport has also mandated that all Arm’s Length Bodies (e.g. Network Rail and National Highways) must assess the WLC impacts of their projects as of 2023 and encourages them to seek formal accreditation to PAS 2080. Therefore, aligning to PAS 2080 would ensure a consistent approach to manage whole life carbon in buildings and infrastructure in line with Scotland’s net zero goals.

Royal Institution of Chartered Surveyors - Whole Life Carbon Assessment for the Built Environment

4.4.7. The Royal Institution of Chartered Surveyors (RICS) ‘Whole Life Carbon Assessment (WLCA) for the Built Environment’^[14] standard allows for consistent and accurate carbon measurement in buildings and infrastructure throughout the built environment life cycle.

4.4.8. The standard enables developers to estimate carbon emissions of a constructed asset from the early development stages through to end of life. It gives visibility the carbon cost of different design options, which is a unique and useful feature of the RICS standard.

4.4.9. It can be used by a range of professionals in the built environment, including contractors, developers, quantity surveyors, cost consultants and building surveyors to designers, engineers and environmental, social, and governance (ESG) consultants. The standard aids decision making during the design, procurement, construction and use phases of a project, by providing WLC assessors with data to inform decision making in line with evolving national and local legislation on WLCAs.

4.4.10. The standard sets out a framework for conducting WLCAs, including how to determine material quantities, assumptions, scenario setting, and carbon data sources for each life cycle stage. It also provides reporting templates for buildings and infrastructure projects, which can be used to report carbon emissions from each life cycle stage.

Institute of Environmental Management and Assessment Guidance

4.4.11. The Institute of Environmental Management & Assessment (IEMA) ‘Guide for Assessing Greenhouse Gas Emissions and Evaluating their Significance’^[15] assists carbon practitioners in conducting carbon assessments, mitigation and reporting in statutory and non-statutory Environmental Impact Assessment (EIA).

4.4.12. The Guide sets the assessment methodology that greenhouse gas (GHG) emissions assessments within EIA should use to quantify the whole life net GHG emissions associated with proposed project and baseline scenarios. It also sets criteria for evaluating the significance of whole life carbon emissions impact.

4.4.13. The GHG quantification principles set out in the IEMA Guide follow other best practice standards including PAS 2080, the GHG Protocol Corporate Standard^[16] and BS EN ISO 14064-2^[17].

Low Energy Transformation Initiative Guidance

4.4.14. The Low Energy Transformation Initiative (LETI) Climate Emergency Design Guide^[18] outlines the requirements for new buildings to ensure national climate change targets are met and to support a net zero carbon future. The guide was developed by over 100 LETI volunteers over a period of 12 months.

4.4.15. It is aimed at developers/landowners, designers, policy makers, and the supply chain, and provides guidance for assessing whole life carbon emissions associated with new buildings. It also aims to help to define ‘good’ and to set clear and achievable targets for new buildings.

4.4.16. The LETI guidance sets out the requirements of four key building archetypes (small scale residential, medium/large scale residential, commercial offices, and schools).

4.4.17. Design teams are able to register their projects as LETI Pioneer projects, promoting the sharing of knowledge and lessons learned with other design teams assessing the aiming to reduce whole life carbon emissions associated with their projects.

Greater London Authority Guidance

4.4.18. The ‘Whole Life-Cycle Carbon Assessments Guidance’^[19] produced by Greater London Authority (GLA) in 2022 is a comprehensive guidance document that sets out the principles for carrying out whole life carbon assessments in line with London Plan Policy SI 2 ‘minimising greenhouse gas emissions’. The Guidance is aimed at developers, planning applicants, designers, and local government officials.

4.4.19. The Guidance provides an overview of what WLC emissions are and explains how to prepare a quantitative assessment using a proposed assessment template. It also includes information on design principles and WLC benchmarks to support developers in designing low carbon projects from the outset.

4.4.20. WLC principles included in the Guidance reflect other best practice standards such as PAS 2080:2023 by encouraging reuse and retrofit of existing structures in the first instance, using repurposed or recycled materials, deploying low carbon alternatives, minimising operational energy and water usage, and giving consideration to circular end-of-life solutions. Additionally, it encourages efficient and regenerative design and construction methods as well as “designing for durability and flexibility” to reduce repair and replacement costs and emissions.

4.4.21. The Guidance provides a comprehensive set of steps to assess WLC and report this to GLA with instructions of what to expect for each stage of the project life cycle and how to address this within the planning process. It also outlines a specified methodology for quantification including alignment to BS EN 15978:2011^[20] and the RICS Professional Statement and encourages the use of other relevant best practice guidance such as PAS 2080 (explored in Section 4 of this report above).

4.5 Guidance for Planning Officials

4.5.1. The information sources, tools, methods, and approaches outlined above are useful references for stakeholders across the planning and development process including developers and planning officials making decisions on individual planning applications. However, there are some guidance documents developed specifically for planning officials as explored below. It should be noted that whilst these are not Scotland specific, they can be used to inform the decision making process.

4.5.2. Additional guidance documents referenced by stakeholders through our engagement process (detailed in Section 8 of this report) include the Scottish City Region & Growth Deals ‘Carbon Management Guidance for Projects and Programmes’^[21] and the Moray Council ‘Carbon Guidance for Planning Applications and S36 and S37 Consents’^[22]. These are explored in more detail in Section 5 and Section 9 of this report respectively.

Royal Town Planning Institute Guidance

4.5.3. The ‘Climate Crisis – A Guide for Local Authorities on Planning for Climate Change’ is a comprehensive guide written by the Royal Town Planning Institute and the Town and Country Planning Association. It provides an accessible introduction to the broad issues involved in planning for climate change and is designed to help planners and politicians play their full part in tackling the climate crisis.

4.5.4. The guide is intended to inform the preparation of l development plans by local and combined authorities in the UK and provides a broad understanding of how to reduce carbon emissions while also managing climate impacts such as flooding and overheating which enables for understanding the broader climate impacts of planning decisions.

UK Green Building Council Whole Life Carbon Roadmap

4.5.5. The UK Green Building Council’s ‘Net Zero Whole Life Carbon Roadmap for the Built Environment’ was developed in collaboration with more than 100 organisations including the World Green Building Council and BuildingLife^[23]. The roadmap provides a common vision with agreed actions to enable net zero through the effective whole life carbon management of buildings and infrastructure.

4.5.6. The roadmap is split into four key outputs:

• The Main Trajectory Report: Provides an overview of the project, key findings, and the steps industry must take to achieve net zero by 2050.
• The Technical Report: Goes into more depth into the numbers behind the roadmap and how the team arrived at the conclusions.
• The Stakeholder Action Plans: Gives clear guidance for a range of built environment stakeholders as they work to meet these targets.
• The Summary for Policy Makers: Recommends the key policies government should implement to enable industry to meet these targets.

4.5.7. The roadmap informs assessing the significance of whole life carbon emissions of a proposal within the planning process as it provides a clear trajectory to net zero by 2050 for the built environment, setting out step-by-step actions for different stakeholders to take. It highlights a carbon budget specific to the built environment and presents a view of the specific actions and steps needed throughout the sector in order to reduce whole life carbon.