According to the latest data from the Office for National Statistics, the median energy efficiency score for England was 67 and 65 in Wales, equivalent to a D.
An EPC D rating is 55 to 68 points, band C is 69 to 80 points, band B is 81 to 91 points and A is 92 points or more.
The government is in the process of hammering out legislation that could mandate that new private rental tenancies in 2025 should have an EPC rating of C or higher, and this could apply to all existing private rental tenancies by 2028.
Yorkshire and the Humber had the lowest average score of 65, which compares to London and the South East that had the highest at 68.
In England, the median energy efficiency ranged from 77 in Tower Hamlets, London, to 47 in Isles of Scilly in South West.
In Wales, the highest median was 68 for Newport, Monmouthshire, Torfaen and Cardiff. The lowest was 58 for Gwynedd and Ceredigion.
The report continued that in local authority districts, 15 per cent had more than half of dwellings with an energy efficiency band of C or above. Two thirds of these local authorities were in London or South East.
Flats and maisonettes most energy efficient
Flats and maisonettes were the most efficient with average rating of 72 in England and 73 in Wales, equal to a C rating.
Detached and terraced dwellings scored the lowest in Wales at 63, compared to England where the lowest was semi-detached at 64. Both are equal to a D rating.
The report said that this could be due to external wall exposure being higher in detached properties than in flats or maisonettes.
Owner-occupied dwellings were the lowest in England and Wales at 64 and 62 respectively, equivalent to a D rating.
Social rented dwellings had the highest scores in England and Wales of 70 and 71 apiece, equal to a C rating.
Age of the property was also a factor, with properties constructed after 2021 having a median energy efficiency score of 83, equal to a band B rating.
Those constructed prior to 1930 had a media score of 59 in England and 57 in Wales, equivalent to an E rating.
The report said that around a third, 33 per cent, of properties in Wales were built prior to 1930, compared to England at 23 per cent.
