Net zero carbon in construction procurement: the official guidance, explained

The key facts

• The guidance note (September 2022) applies to all central government departments, executive agencies and non-departmental public bodies on a comply or explain basis. Wider public sector authorities are encouraged to apply it.
• The UK legislated on 27 June 2019 for at least a 100 per cent reduction in greenhouse gas emissions by 2050 against 1990 levels, with interim targets of a 68 per cent cut by 2030 and 78 per cent by 2035.
• Around 40 per cent of UK carbon emissions are linked to the built environment, construction activity accounts for around 50 million tonnes of CO2, and the sector generates around 60 per cent of UK waste.
• Under PPN 06/21, bidders for central government contracts over 5 million pounds a year must publish a Carbon Reduction Plan covering Scope 1, Scope 2 and a subset of Scope 3 emissions. Failure is likely to lead to exclusion at selection.
• Contracting authorities should require a Whole Life Carbon Assessment as part of the tender for new built assets and large-scale refurbishments.
• Requiring bidders to hold accreditation to a particular standard is likely not justifiable under procurement regulations, but accreditation can be accepted as evidence of ability to deliver.
• The Environment Act 2021 introduced biodiversity net gain: a minimum 10 per cent gain with habitat secured for at least 30 years, which the note anticipated becoming mandatory in 2023.
• The Construction Innovation Hub Value Toolkit defines value across four capitals: natural, human, social and produced.

What this guidance note is and who it applies to

Promoting Net Zero Carbon and Sustainability in Construction is a Cabinet Office guidance note, published in September 2022 as part of the Construction Playbook suite. It collates practical resources on decarbonisation for anyone procuring construction and infrastructure projects and programmes, and walks through the procurement lifecycle: pipelines and longer term contracting, early market engagement and specification, delivery models and contracting, and delivery through to operation, supported by case studies including Foleshill Health Centre, SEISMIC, HS2 and TEAM2100.

It applies to all central government departments, their executive agencies and non-departmental public bodies from publication, on the same comply or explain basis as the Playbooks. Contracting authorities in the wider public sector are encouraged to apply it too. Proportionality and relevance remain the guiding concepts: the note does not override the separate scope and qualifying criteria of the policies and standards it references.

The policy backdrop: statutory targets and why construction matters

The UK legislated in June 2019 for at least a 100 per cent reduction in net greenhouse gas emissions by 2050 against 1990 levels. The target is managed through five-year carbon budgets set by the Climate Change Committee, with intermediate targets of a 68 per cent reduction by 2030 and 78 per cent by 2035. Net zero covers all seven Kyoto Protocol gases, reported in carbon dioxide equivalent (CO2e), and the Climate Change Committee has also stressed climate adaptation and the resilience of the built environment.

Construction sits at the centre of that challenge. Around 40 per cent of UK carbon emissions are linked to the built environment, construction activity accounts for around 50 million tonnes of CO2 (over half from product and materials production, with steel and cement alone around 15 per cent of global emissions), and the sector generates around 60 per cent of UK waste. The note is blunt that the most effective way to reduce carbon is to design it out, rethinking whether traditional infrastructure is needed at all, and getting the thinking right at the outset.

The note also flags the direction of travel on value: at the time of writing, authorities had to pursue the Most Economically Advantageous Tender, but the government had signalled its intention through the Procurement Reform Bill to move to the Most Advantageous Tender, to make clear that buying on lowest up-front capital cost is unlikely to deliver best value. The National Procurement Policy Statement makes tackling climate change and reducing waste a national priority outcome.

What it asks of procurement: whole life carbon from strategy to specification

Every contracting authority should have a strategy to reach net zero across its estate and infrastructure by 2050, developed as part of a Strategic Asset Management Plan, and that strategy should create a clear line of sight into outcome specifications, delivery model decisions, contract terms, KPIs and reporting. Whole life carbon, the sum of embodied, operational and end of life emissions, should be embedded from business case into design.

Practically, the note asks authorities to resource net zero within the project team, include sustainability in pre-procurement market engagement, design on a fabric first basis to maximise heat efficiency, consider climate resilience over the asset's design life, select a whole life carbon methodology early (such as PAS 2080 for infrastructure), build carbon outcomes into the Should Cost Model, and require a Whole Life Carbon Assessment in tender documentation for new builds and major refurbishments, run to consistent guidelines so results can be benchmarked.

The Construction Innovation Hub Value Toolkit supports this by helping authorities define value across four capitals: natural, human, social and produced. Its five streams, value definition, client approach, risk, measurement and evaluation, and appointments, give a structured way to carry that definition of value from business case through to contract.

Carbon Reduction Plans, reporting and standards

At supplier selection, PPN 06/21 requires organisations bidding for major government contracts, over 5 million pounds a year where relevant and proportionate, to commit to net zero by 2050 and publish a Carbon Reduction Plan on their website, updated at least annually. The plan must report Scope 1 and Scope 2 emissions and a defined subset of Scope 3, in CO2e, and set out the environmental management measures in effect. Failure to comply is likely to lead to exclusion at the selection stage.

For reporting, the note points to recognised standards such as the Greenhouse Gas Protocol, and to verification standards ISO 14064-3 and ISAE 3410. Authorities should not prescribe particular carbon calculation tools, but can seek assurance that supplier approaches are consistent with the project's chosen standards. On standards generally, the note is careful: requiring accreditation to a named standard in a tender is likely not justifiable under the procurement regulations, but evidence of accreditation can be accepted as evidence of capability. It also encourages engagement with industry initiatives such as the UK Green Building Council's net zero framework, the Carbon Reduction Code, CO2nstruct Zero, the Low Carbon Concrete Routemap and the steel decarbonisation roadmap.

Beyond carbon: biodiversity, circular economy and the Environment Act principles

Net zero sits within a wider set of environmental obligations. The Environment Act 2021 established five principles for policymakers, integration, prevention, rectification at source, polluter pays and precaution, and authorities should have regard to them when designing projects and specifications. The Act also introduced biodiversity net gain: a minimum 10 per cent gain calculated with the Biodiversity Metric, habitat secured for at least 30 years, delivery on-site, off-site or through statutory credits, and application to Nationally Significant Infrastructure Projects. The note anticipated this becoming mandatory in 2023, supported by BS 8683:2021.

On the circular economy, with construction generating around 60 per cent of UK waste, authorities should promote reuse and recycling through tender requirements, specifications and standards such as BES 6001 for responsibly sourced construction products. Digital technologies and Modern Methods of Construction are treated as essential enablers throughout: better designs that need fewer materials, precision manufacture that cuts waste, and accurate monitoring and reporting of emissions.

How eSourcing Data helps

The guidance note turns net zero from an aspiration into a set of procurement artefacts: market engagement records, outcome specifications, Whole Life Carbon Assessment requirements in tender packs, Carbon Reduction Plan checks at selection, and carbon KPIs in contracts. eSourcing Data lets contracting authorities build those artefacts into the procurement itself, publishing requirements in structured tender documents, collecting supplier responses and Carbon Reduction Plan evidence through the platform, and holding it all in one auditable record.

Selection and evaluation workflows support consistent, proportionate checks, so a qualifying procurement never goes out without the PPN 06/21 question set, and evaluation of carbon and sustainability criteria is scored and documented alongside price and quality. Reporting tools help teams evidence their comply or explain position across a portfolio rather than one project at a time.

For the high volume of smaller and below-threshold works where full whole life carbon assessment would be disproportionate, below-threshold workflows keep a lighter set of sustainability questions in play, so the organisation's net zero strategy reaches every purchase, not just the flagship schemes.

What to do about it

1. 1Put a net zero strategy covering construction and operational emissions into your Strategic Asset Management Plan, and map it into procurement documents.
2. 2Require a Whole Life Carbon Assessment, run to consistent published guidelines, in tenders for new builds and large refurbishments.
3. 3Include carbon and sustainability in pre-procurement market engagement so the supply chain can propose innovative options early.
4. 4Apply the PPN 06/21 Carbon Reduction Plan check at selection on qualifying contracts over 5 million pounds a year.
5. 5Define value using the Value Toolkit's four capitals and reflect it in evaluation criteria and weightings.
6. 6Accept accreditation to standards as evidence of capability, but do not make accreditation itself a tender requirement.
7. 7Plan now for biodiversity net gain and circular economy requirements, including the minimum 10 per cent gain and 30-year habitat commitments.