Most UK contractors lack supplier carbon data for embodied carbon reporting. Here is a practical method to start measuring and improving without perfect data.
Why this matters now
In 2026, embodied carbon has shifted from voluntary reporting to a procurement requirement across public sector projects.
Two policy drivers are central:
• PPN 006 mandates carbon reduction plans including relevant Scope 3 emissions
• NHS Evergreen Level 1 requires suppliers to report Scope 1, 2, and relevant Scope 3 categories from April 2026
For contractors, this specifically includes upstream purchased goods and services, meaning materials and subcontracted work [1][2].
The issue is not willingness to report. It is lack of supplier data.
What is embodied carbon and why it is now a tender issue
Embodied carbon refers to the total lifecycle emissions associated with materials and construction activities, including:
• Raw material extraction
• Manufacturing
• Transport
• Installation
This differs from operational carbon, which relates to energy use during a building’s life.
Historically, operational carbon was the primary focus of building performance. However, as operational emissions reduce through energy efficiency and electrification, embodied carbon now represents a growing share of total lifecycle emissions. In many projects, it can account for more than half of the total carbon impact at completion.
This shift is why embodied carbon is now moving into procurement. Clients are no longer only interested in how a building performs in use. They are also assessing the carbon impact of how it is built.
Embodied carbon is now appearing in:
• Public sector tender specifications
• Carbon Reduction Plans under PPN 006
• Net zero commitments aligned with Science Based Targets initiative
For contractors, this is not theoretical. It directly affects:
• Bid scoring and competitiveness
• Framework eligibility
• Client compliance requirements
In practice, this means contractors are increasingly expected to provide a quantified embodied carbon figure at tender stage, even when supply chain data is incomplete.[3].
The data gap most contractors face
Across the UK construction supply chain:
• Environmental Product Declarations are not consistently available
• Material carbon data is rarely included in supplier quotes
• Data is fragmented across invoices and spreadsheets
This creates a critical risk during tendering:
• Leaving embodied carbon blank signals non compliance
• Providing unclear figures triggers procurement challenges
Contractors are expected to report without having the data infrastructure to do so.
Using industry average factors as a defensible baseline
Where supplier data is unavailable, the accepted starting point is industry average emission factors.
Recognised methodologies include:
• ICE database
• RICS guidance
• CIBSE frameworks
These sources provide benchmark values such as kgCO2e per tonne of material [4][5].
A defensible baseline requires:
• Clear identification of the data source
• Transparent assumptions such as transport and material type
• Explicit labelling of estimated versus actual data
This ensures your number is auditable and procurement ready, even if incomplete.
Prioritising by material impact
In most construction projects, a small number of materials dominate embodied carbon:
• Concrete
• Steel
• Insulation
These typically account for 70 to 80 percent of total embodied carbon [4].
A practical approach is to:
- Start with structural materials
- Focus on high volume items
- Target high impact components
Attempting to model every material at once often reduces accuracy rather than improving it.
Engaging suppliers to get actual data
Industry averages are a starting point, but improvement depends on supplier engagement.
A simple four question approach works effectively:
- Do you have an Environmental Product Declaration for this product
- If not, can you provide a carbon factor in kgCO2e per unit
- What methodology or standard was used
- Can this data be improved within the next 12 months
This creates a structured pathway from estimates to partial supplier data to verified EPDs.
Reporting embodied carbon in a bid or CRP
The objective is not perfection. It is credibility and transparency.
A strong submission should include:
• Total embodied carbon estimate in tonnes CO2e
• Methodology such as ICE based factors
• Scope boundary
• Data quality statement
• Improvement plan
This aligns with expectations under:
• PPN 006
• NHS Evergreen Level 1
Procurement teams are assessing whether your approach is structured, repeatable, and improving over time.
From manual effort to structured workflow
To scale this process, contractors need a consistent system that:
• Captures material quantities
• Applies industry average factors
• Integrates supplier data over time
• Maps outputs to Scope 3 categories
Platforms like SustainZone support this workflow, with outputs feeding into tools such as SustainGate for Carbon Reduction Plans.
References
[1] UK Government. PPN 006 Taking account of Carbon Reduction Plans in procurement
[2] NHS England. NHS Evergreen Level 1 Supplier requirements for net zero and Scope 3
[3] Greenhouse Gas Protocol Scope 3 Standard Category 1 Purchased Goods and Services
[4] RICS Whole Life Carbon Assessment for the Built Environment
[5] ICE database Industry average embodied carbon factors
[6] CIBSE TM65 and embodied carbon guidance