How raw evidence becomes a score
The benchmark is evidence-led. Every company score traces back to public sustainability evidence, scored against a fixed rubric, weighted by metric importance and rolled up into pillar and final scores.
Sustainability reports, TCFD/CSRD filings, websites and disclosures.
Evidence is mapped to the relevant metric and pillar.
Each metric is scored against an evidence-quality rubric.
Score × (weight ÷ 5). E.g. weight 7 × score 4 = 5.6 pts.
Weighted points sum into Future Commitments / Env. Action / Governance.
Three pillar scores combined into the headline benchmark score.
Worked example
Water withdrawal carries a weight of 6 points. A company scoring 4 / 5 on evidence quality contributes 4.8 points toward the Environmental Action pillar.
All 15 metric contributions are then summed into pillar scores (25 + 55 + 20) to produce the final score out of 100.
Score → % of metric weight
| Score | % of weight | Meaning |
|---|---|---|
| 5/5 | 100% | Full credit, strong quantified evidence |
| 4/5 | 80% | Good quantified evidence; minor gaps |
| 3/5 | 60% | Partial / intensity-only disclosure |
| 2/5 | 40% | Policy-level evidence only |
| 1/5 | 20% | Limited public disclosure |
| 0/5 | 0% | Not clearly disclosed in reviewed public materials |
Pillar architecture
Future Commitments
Forward-looking climate targets, interim milestones and value-chain emissions scope.
Environmental Action
Operational performance: emissions intensity, water, biodiversity, habitat, rehabilitation, residue and circular resource use.
Governance & Accountability
Environmental compliance, permit and incident discipline, supplier and contractor environmental due diligence.
Per-metric rubric (0–5)
- 5Full quantified disclosure with assurance or progress vs baseline
- 4Strong quantified disclosure; minor gaps
- 3Partial / intensity-only disclosure
- 2Policy-level evidence only
- 1Limited public disclosure identified
- 0Not clearly disclosed in reviewed public materials
Treatment of missing or non-applicable evidence
Scored 0 where the metric is material but evidence is not clearly disclosed in reviewed public materials. Weight remains in the denominator.
A sector-relevant substitute is used (e.g. sediment management for marine contractors in lieu of tailings). Where no substitute applies, the metric weight is removed from the denominator.
Reporting boundary and proxy evidence
Some companies have strong Group-level disclosure, while smaller entities do not publish standalone reports. Where this happens, parent-company or proxy evidence is used and is clearly labelled.
Brett Aggregates' 2024 report is used as Brett-level evidence and is a strong proxy for Britannia Aggregates as Brett is the sole owner. For Volker Dredging it is used as Brett-linked operating-context evidence, not direct Volker-only performance.
Boskalis Group disclosure is used as group-level proxy evidence where Westminster-Gravels-specific sustainability metrics are unavailable.
Group-level disclosure is strong, but marine-asset-specific evidence may be only partially available; scores reflect the Group lens.
Project-level and permitting evidence is available, but operational KPIs are limited because the asset is pre-production.
Benchmark caveat
Scores are based on reviewed public sustainability evidence and are intended for comparative benchmarking. They should not be read as a definitive ESG rating. Higher scores generally indicate stronger quantified disclosure, clearer targets and more mature sustainability systems. Lower scores may reflect limited public disclosure, proxy reporting boundaries, smaller company scale or development-stage assets rather than weaker sustainability performance.
The same 15-metric framework is applied across all companies for comparability, but each metric is interpreted through a sector-relevant lens.