From data overload to delivery: How Galliford Try builds Scope 3 maturity through portfolio learning

Scope 3 embodied carbon is no longer a knowledge gap. Across the construction sector, organisations understand where the majority of emissions sit. What remains unresolved is how to turn that understanding into consistent action across projects, teams, and supply chains. That challenge was addressed by Allan Smith of Galliford Try at the Carbon Experts Summit in London, outlining how a portfolio-led, data-driven methodology can move Scope 3 from measurement to delivery at scale.

“We don’t have a data problem in Scope 3 anymore — we have a decision problem. Until carbon data is structured so teams can act on it repeatedly, it won’t change outcomes.” — Allan Smith, Low-Carbon Manager at Galliford Try 

Many organisations follow the same trajectory: early confidence driven by limited metrics, followed by overload as datasets multiply faster than teams can interpret them. At that point, Scope 3 risks becoming a reporting exercise rather than a delivery tool. The organisations making measurable progress are those that treat Scope 3 as a maturity journey, not a calculation problem.

Why Scope 3 maturity matters more than perfect data

Scope 3 maturity is defined by three capabilities:

1. Alignment – targets that connect materials, buildings, and portfolios
   
   
2. Comparability – data that supports decisions, not just disclosure
   
   
3. Learning loops – the ability to improve outcomes across projects over time
   

Without these, even highly detailed carbon models struggle to influence design and procurement in meaningful ways.

This is where methodology matters. Organisations that mature fastest prioritise the biggest drivers first, apply consistent benchmarks, and accept that insight compounds through repetition, not one-off optimisation.

Aligning targets across construction materials and buildings

A defining feature of mature Scope 3 strategies is alignment across scales.

At the material level, setting explicit intensity targets creates clarity for procurement and supplier engagement. For example, a 2030 target of 0.93 tonnes CO₂e per tonne of steel provides a clear reference point for evaluating products, fabrication routes, and supply chain performance against an industry-aligned decarbonisation pathway.

At the building level, alignment with recognised embodied carbon benchmarks provides a reality check on whether material-level improvements are sufficient. Current reference points shaping UK and international expectations include:

• 600 kgCO₂e/m² – Net Zero Public Sector Building Standard (Scotland)
  
• 530 kgCO₂e/m² – UK Net Zero Carbon Buildings Standard (2025)
  
• 395 kgCO₂e/m² – UK Net Zero Carbon Buildings Standard (2030)

While largely voluntary, these benchmarks increasingly function as market compliance signals. They influence public-sector procurement, funding decisions, and client requirements, making early testing essential for managing both carbon and commercial risk.

Portfolio assessment: Where learning actually happens

Project-level optimisation alone does not build organisational capability. Scope 3 maturity emerges when performance is assessed across portfolios, using a consistent methodology.

When multiple projects are benchmarked against the same embodied carbon pathways, patterns emerge:

• Some schemes sit well above 800 kgCO₂e/m²
  
• Others approach 400 kgCO₂e/m² for comparable scopes

This spread is not a failure of consistency; it is evidence of learning in progress. It shows where design strategies, structural efficiency, specification choices, and procurement approaches materially affect outcomes. This is what allows organisations to standardise better decisions, rather than relying on exceptional teams or one-off projects.

“Single projects can look exceptional or disappointing in isolation. Portfolio assessment is where you see which decisions genuinely work — and which ones you can scale,” said Allan Smith, Low-Carbon Manager at Galliford Try

Portfolio benchmarking enables organisations to move beyond anecdotal success. Instead of asking “Which project performed best?”, mature teams ask “Which decisions consistently reduce carbon, and can we repeat them?”

Steel as a proof point for decision maturity

Steel often becomes the focus of Scope 3 discussions because it meets three critical criteria:

• It is a significant contributor to embodied carbon
  
• It has relatively mature industry benchmarks
  
• It sits at the intersection of design intent and supply chain choice
  

Across multiple projects, steel frame assessments commonly show:

• An average frame weight of 71 kg/m²
• An average frame embodied carbon intensity of 120 kgCO₂e/m²

“Targets like 0.93 tonnes of CO₂e per tonne of steel only matter if they change procurement conversations. Once teams can see the gap, they know exactly where to focus next,” said Allan Smith, Low-Carbon Manager at Galliford Try.

The critical insight is not the averages — it is the variation. Similar structural solutions can produce markedly different carbon outcomes depending on fabrication routes, electricity sources, scrap content and supplier performance.

This highlights a core maturity lesson: material quantity alone is not a reliable proxy for Scope 3 impact. Decision-ready data must capture how products are made, not just how much is used.

Turning Scope 3 assessment into improvement targets

Mature Scope 3 strategies close the loop between assessment and action.

A detailed steel package assessment for a secondary school project illustrates this clearly:

• 951.347 tonnes of steel supplied
  
• 1.037 tCO₂e per tonne (A1–A3)
  
• 1.117 tCO₂e per tonne including transport
  

Under the Construction Leadership Council scale, this corresponds to an “E” rating. A future target of <0.93 tCO₂e/t defines a clear improvement gap of at least 0.187 tCO₂e per tonne for comparable scopes.

This is where Scope 3 maturity becomes operational. Instead of broad ambition, teams gain a quantified delta that can inform future design influence, supplier engagement and procurement strategy.

A hierarchy that ensures carbon reduction

Effective Scope 3 strategies recognise that not all decisions carry equal weight. A simple hierarchy helps focus effort where it matters most:

• Avoid – reduce material demand through smarter design
  
  
• Switch – select lower-carbon products through supplier collaboration
  
  
• Improve – support innovation and share learning across projects
  
  

This hierarchy ensures that carbon reduction is addressed early, when leverage is highest, and that lessons learned on one project inform the next rather than being lost at handover.

Why this Scope 3 approach scales globally

As whole-life carbon disclosure becomes standard practice across the UK and internationally, competitive advantage will sit with organisations that can apply Scope 3 insight repeatedly, not just report it once.

Portfolio learning, aligned benchmarks, and decision-ready data allow carbon performance to improve cumulatively. Steel provides a clear illustration today, but the methodology is designed to extend across other high-impact materials as data maturity grows.

Scope 3 maturity is not about perfection. It is about building systems that learn and using carbon data to support better decisions, consistently and at scale.

Frequently asked questions — Scope 3

What are Scope 3 emissions in construction?

Scope 3 emissions are all indirect carbon emissions across the value chain, including embodied carbon in materials like steel and concrete, transport, and waste, and they often represent the largest portion of a construction project’s footprint. Galliford Try focuses on understanding and reducing Scope 3 through portfolio LCA and supplier engagement, while One Click LCA tools help quantify and compare these impacts consistently.

Why is embodied carbon important in Scope 3 reporting?

Embodied carbon — the emissions from material extraction, manufacture, transport and construction — often drives 80 – 95 % of Scope 3 in built assets. Accurately measuring it is critical for real reduction rather than reporting alone. One Click LCA tools support consistent embodied carbon accounting, and Galliford Try’s methodology integrates these results into decision-making across projects.

How do industry benchmarks like 600, 530 and 395 kgCO₂e/m² relate to compliance?

These figures represent embodied carbon intensity pathways used in UK practice: 600 kgCO₂e/m² (Net Zero Public Sector Standard), 530 (UK NZCBS 2025) and 395 kgCO₂e/m² (UK NZCBS 2030). While not all are statutory, they act as market compliance signals and planning or procurement expectations. Galliford Try uses benchmarks like these in portfolio LCA, with One Click LCA enabling consistent comparison.

How can contractors reduce Scope 3 carbon in materials like steel?

Contractors reduce Scope 3 by prioritising design decisions and supplier engagement: set clear targets (e.g., 0.93 tCO₂e/t steel), use supplier-specific EPDs, and compare product options early. Galliford Try’s methodology demonstrates this, and One Click LCA allows teams to model different material scenarios and track improvement across projects.

What role does portfolio LCA play in mature Scope 3 strategies?

Portfolio LCA compares embodied carbon outcomes across multiple projects to identify what decisions consistently reduce impact. This helps organisations like Galliford Try move from isolated success to company-wide learning. One Click LCA provides Portfolio Analytics tools for standardised data and benchmarks, enabling organisations to scale carbon literacy and improvement.

Are there regulatory drivers for Scope 3 carbon reporting in the UK and globally?

Yes. UK and EU frameworks, e.g., Corporate Sustainability Reporting Directive (CSRD), are increasingly requiring Scope 3 disclosure, pushing comprehensive carbon reporting beyond voluntary practice. National guidance, such as UKGBC’s Scope 3/embodied carbon guidance, emphasises aligning project LCAs with organisational reporting. Galliford Try aligns its internal targets with these expectations, and One Click LCA helps clients prepare for evolving standards.