Trust and transparency
Data sources
This page sets out exactly which official material EPC Benchmark uses, how it is licensed, what it covers, and which parts of the site are our own analysis rather than official record.
Last reviewed: 23 August 2026
Official source material versus EPC Benchmark analysis
Official source material
- Domestic EPC certificate records, including efficiency scores and bands.
- Recorded property attributes: type, built form, age band, floor area.
- Recommendation records, their recorded order and indicative cost ranges.
EPC Benchmark analysis
- Usable-record filtering and latest-certificate deduplication.
- Peer-group definition, the minimum cohort target and the widening order.
- Median comparison, approximate percentile and all plain-English wording.
EPC Benchmark is independently operated. The full method is set out on the methodology page.
What this release uses
The comparison figures come from the official England and Wales domestic certificate-history export (27,654,564 rows) drawn from the bulk-data service, reduced to 19,324,312 current properties. Recommendations come from the separate domestic recommendations export (102,824,532 rows), summarised by national property type and construction age band.
Recommendation figures are associations with a certificate's total potential SAP gap, not item-specific causal uplifts. The average shown is the average total current-to-potential certificate gap for properties carrying that recommendation. It is not the point uplift of that measure, and it does not show cause and effect. No cost estimates are shown, because this release does not contain validated current costs.
What the official data covers
The government bulk-data service covers England and Wales. It includes certificates registered since 2012, and records remain published after a certificate has expired or been replaced by a newer assessment, so an individual record may not describe a home as it stands today.
It is a register, not a census
The data is event-driven: a building appears when an EPC is lodged, usually on sale, letting, construction or certain grant work. Buildings that have never had a certificate lodged, records with missing values, and properties covered by exemptions are simply not represented. Absence from the data does not mean a property does not exist, and the register is not a complete picture of every building.
Scotland is out of scope
Scotland operates a separate energy performance register under its own arrangements. Scottish certificates are not part of the England and Wales bulk data and are outside EPC Benchmark’s current coverage.
Licence and attribution
Contains public sector information licensed under the Open Government Licence v3.0.
© Crown copyright and database right. Crown copyright material is used under the Open Government Licence v3.0. This acknowledgement does not imply that the licensor endorses EPC Benchmark, its analysis or its interpretation in any way.
Official sources
These links open official government and National Archives pages. Guidance changes, so always check the current version.
- Get energy performance of buildings data
The official bulk-data service for England and Wales domestic certificate records and recommendation records.
- Find an energy certificate
The official register for looking up the current certificate for an individual property.
- Technical notes and limitations
Government guidance on how the certificate data is compiled and what it can and cannot be used to say.
- Open Government Licence v3.0
The licence under which the public sector information used here is made available.
How often this is updated
This is not live data and it does not update automatically. EPC Benchmark does not query an official service in real time and has no automated, fixed refresh cadence. This release is based on a source snapshot ending 31 July 2026 and was generated on 23 August 2026. When a new bulk-data analysis is published, the release will be versioned and dated and this page will be updated to match.