EPC Register — Energy Performance of Buildings Data API
The MHCLG-operated public API for England and Wales covers three
certificate types and exposes capabilities for searching them, fetching
the full record by certificate number, decoding the numeric fields
inside a certificate, sync'ing against a change-feed, and downloading
the bulk datasets.
Certificate types
- Domestic EPC — residential properties.
- Non-domestic EPC — commercial and public buildings. Search rows
carry a relatedRrn linking to a recommendations report.
- Display Energy Certificate (DEC) — operational ratings for public
buildings.
All three search the same way: by postcode, free-text partial address,
UPRN, one or more council names, one or more parliamentary constituency
names, one or more efficiency bands (A–G), and/or a registration
date window.
Search behaviour
- At least one filter is required: postcode, address, UPRN, councils,
constituencies, efficiency bands, or a date_start/date_end window.
- date_end defaults to yesterday. The date range cannot include today.
- Pagination uses current_page (1-indexed) and page_size (max 5000,
default 100). The response carries pagination.totalRecords,
totalPages, nextPage, and prevPage.
- Search rows are summaries: addressLine1..4, postcode, postTown,
council, constituency, currentEnergyEfficiencyBand, uprn,
certificateNumber, registrationDate. Non-domestic and display rows
also include relatedRrn.
- Use efficiency_ratings to filter by band(s) such as ["A","B","C"].
Single certificate
Once a certificate number is known (from a search row's
certificateNumber, or a 9999-9999-9999-9999-9999-style lookup),
fetch the full certificate to get the underlying SAP / RdSAP / SBEM
record — fabric, heating, lighting, ventilation, address detail, and
assessor information.
Decoding numeric fields in a full certificate (do not skip this)
The full certificate document is dominated by integer codes —
built_form: 4, property_type: 2, main_fuel: 39,
transaction_type: 6, report_type: 3, construction_age_band,
tenure, etc. These are meaningless on their own.
The certificate carries a schema_type field (e.g. "SAP-Schema-18.0.0",
"RdSAP-Schema-21.0.1"). Pass that as schema_version when decoding so
the correct label table is used — the same code can map to different
labels under different schema versions.
Workflow when interpreting a certificate:
- List the available code-lookup tables once to discover which fields
are decodable (the available tables include built_form,
property_type, main_fuel, transaction_type,
construction_age_band, tenure, glazed_type, glazed_area,
mechanical_ventilation, ventilation_type, energy_tariff,
water_heating_fuel, cylinder_insulation_thickness,
heat_loss_corridor, improvement_description,
improvement_summary, and energy_efficiency_rating).
- For each integer field of interest, decode the value by passing the
field name, the integer value as a string, and the certificate's
schema_type.
Change feed
A change-feed capability returns a list of certificate events of types
removed and uprn_updated between two dates. Use it to reconcile a
cached set of certificate numbers against the live register. The window
cannot include today.
Bulk datasets
For loading the full register into a warehouse, two read-only
capabilities wrap the bulk-file endpoints:
- A "file info" capability returns fileSize and lastUpdated for an
archive without downloading it. Use it to decide whether the upstream
has refreshed since your last sync.
- A "download URL" capability returns a pre-signed S3 URL with a
~30-second expiry. Start the download immediately; the URL cannot be
reused or shared.
The bulk datasets are: domestic, non-domestic,
non-domestic-recommendations, display, display-recommendations.
Format is json or csv. The two -recommendations datasets are
JSON-only.
Gotchas
- HTTP 404 on a search means "no certificates match", not an auth
failure.
- Postcodes must be valid; partial postcodes are rejected with HTTP 400.
- Council and constituency filters use full names ("Manchester",
"Chelsea and Fulham"), not ONS or constituency codes.
- Address is a partial-match free-text field; combine it with postcode
for precise lookups.
- Bulk-file pre-signed URLs expire in ~30 seconds — they are not a
stable link the user can click later.
