Methodology
A reproducible basis for every assessment.
Carbon Proof assesses each asset against the CRREM decarbonisation pathway for its use and market. This establishes the asset's misalignment year on each pathway assessed and, where misaligned, sets out the interventions required to defer that year, and the latest year to which it can be deferred at all.
GHGe intensity (kgCO₂e/m²/yr)
- CRREM 1.5°C Pathway
- Baseline (no intervention)
- Post-intervention
- Misalignment year
- Misalignment risk
- Energy Conservation Measure (ECM)
Scope of assessment
Assessment covers both energy consumption by carrier and refrigerant-related emissions. Refrigerant charge, leak rate and global warming potential are assessed separately from energy-based carbon intensity; wherever fluorinated gases are present, this data enables the GHGe pathway assessment.
Evidence base
Every figure in an assessment falls into one of two categories: the asset's own data, or a cited external source. Energy consumption and refrigerant data are the building's metered records for the reporting period, never modelled or benchmarked. All other inputs – emission factors, retrofit costs, performance data – are sourced to primary literature, authoritative datasets or recognised industry guidance, with each source recorded against the figure it supports.
Net-zero carbon alignment
Assessment is conducted against the CRREM pathway – the Carbon Risk Real Estate Monitor framework, developed in partnership with the Science Based Targets initiative (SBTi) to provide the real estate sector's 1.5°C-aligned decarbonisation pathways. Each asset is assessed against independent pathway variants: energy and CO₂-only in every case, and GHGe wherever refrigerant emissions are present and assessed.
Building profile
Retrofit planning begins with a review of the asset's fabric, building services and geometry. This determines which interventions apply to the asset, and brings the relevant measure forward where fabric or plant is approaching the end of its service life. Where the data a measure depends on is absent, that measure is excluded rather than assumed. The profile persists as part of the record, tying each recommendation to the specific building features that produced it.
Roadmap engine
The engine identifies the lowest-cost set of measures that holds the asset on its CRREM pathway to a target year. Each candidate set is verified against the same physics model used to produce the baseline assessment before it is accepted. The first set to clear that check is the minimum-cost set – a claim grounded in the process, not asserted from a solver output. The engine also certifies the alignment ceiling: the latest year to which alignment can be held at all for that asset, independent of any budget constraint.
Selected measures are sequenced to the building's capital cycle and costed against published benchmarks. The roadmap is built around expenditure that is already committed, with measures timed to coincide with fabric and plant replacement.
Abatement is calculated on a residual basis: each measure is credited only for the demand it directly addresses, so the roadmap does not overstate the combined effect of measures acting on the same end use.
Verification
Every input is reviewed before it reaches a calculation. Energy consumption is accepted only as raw, per-carrier metered data – never a pre-calculated intensity – with the reporting boundary and any material vacancy declared explicitly. Refrigerant service records are confirmed by the assessor where required, and GHGe assessment cannot proceed while a record remains unconfirmed. Each completed calculation then carries a cryptographic fingerprint of its exact inputs and outputs, recomputed from the stored record and matched before the result is released.
Reproducibility
Every assessment and roadmap retains the exact basis on which it was calculated – not only its own figures, but the reference data and methodology version applied to produce them. A result can be reconstructed and defended on that same basis years later – at refinancing, at sale, or under audit – unaffected by anything published or changed since.