EPC Atlas Research - UK Data Book 2026 Volume One v0.3

Wales EPC Research: Lower Ratings, Solar Evidence and Off-Gas Geography

The Welsh evidence is not one-dimensional: lower EPC ratings coexist with comparatively strong Solar PV evidence and some of the most off-gas local authorities in the study.

Download aggregate data (CSV)Full Data Book (PDF)Methodology

902,603Wales searchable records

54.09%current D-or-below - highest region

2.106%Solar PV: Yes - highest region

69.64%Ceredigion explicit off-gas among known

A two-sided regional picture

Wales has the highest regional D-or-below share at 54.09% and the highest Solar PV: Yes share at 2.106%.

Large recorded improvement gap

30.03% of Welsh records are D-or-below + potential A/B. That is 271,024 records, including 160,361 that are also classified owner occupied and Houses.

Off-gas geography

Ceredigion has 69.64% explicit off-gas among records with known mains-gas status, the strongest qualifying local-authority result in the analysis. Powys records 54.50%.

Heat-pump and renewable evidence

Ceredigion has heat-pump evidence on 9.51% of searchable records. Wales as a region records heat-pump evidence on 2.10%.

Why this is not a league table

The book does not describe Wales simply as “worst” or “best”. Older housing, rurality, off-gas status, renewable evidence and certificate mix coexist. The purpose is to expose overlaps rather than turn the data into a council-performance ranking.

Evidence boundary

The figures describe searchable EPC Atlas records and source fields. They do not automatically identify a current dwelling population, current legal ownership, current occupancy, live equipment condition, installation date, a building survey, a costed retrofit plan or measured energy use.

Source

EPC Atlas UK Data Book 2026, Volume One v0.3, dated 28 August 2026. The full corpus contains 17,624,989 searchable records across ten England-and-Wales regional datasets. Scotland and Northern Ireland are outside the corpus.