An Everest study analyses 15,623,536 home Energy Performance Certificates (EPC) across the country to reveal the best and worst rated areas for energy efficiency. It is explained in an article on the Open Access Government website.
Revealed: The best and worst areas for energy efficiency
Britain’s houses are some of the oldest and coldest in Europe and the cost of heat that leaks from properties are leading to a rise in fuel poverty.
Because of this, experts at Everest conducted an analysis of over 15 million properties across the country revealing the areas that are the most and least energy efficient based on EPC ratings.
Despite being one of the most expensive places to live – London is home to the MOST energy efficient properties in the country (most A- & B-rated EPCs).
Tower Hamlets, Greenwich and City of London top the chart as the three most energy efficient areas according to the data. 29% of Tower Hamlet properties received an A- or B-rated EPC – which is the highest across the country. Followed by Greenwich and City of London with 20% retrospectively.
There has been significant investment in London and Tower Hamlets specifically from local governments.
Despite being one of the most economically disadvantaged areas of the UK, Tower Hamlets has been part of The London Plan and London Climate Change Action Plan strives to ensure that the area has the highest standards of energy efficiency for new build development of any city in the UK. Because of this, Tower Hamlets and areas surrounding the capital have the highest EPC ratings.
When looking outside of London, Dartford (Kent), Uttlesford (Essex), and Basingstoke and Deane (Hampshire) are amongst the top 10 best areas with the most top-rated EPCs.
Homes with an A- or B-rated EPC spend on average £1,104 on their energy bills over 3 years. And those that are benefiting from cheaper bills, are situated within or near the capital. However, the data shows that just 19,832 dwellings benefit from an A- or B-rated EPC.
Most dwellings have a D rating that has energy costs, on average, of £3,228 across 3 years.
There are 6,136,001 dwellings in England Wales with an average D-rated EPC. However, the problem lies among the lowest rated homes.
The worst rated areas for energy efficient properties
1,042,075 dwellings across the country received an F- or G-rated EPC making them the LEAST energy-efficient houses in England and Wales. Those living within these homes are paying on average £5,743.50 for their energy bills across 3 years – 3.5 times more than those with an A- or B-rated EPC.
Isles of Scilly, Gwynedd, and Ceredigion are the three WORST areas. A huge 35% of properties within the Isles of Scilly received an F- or G-rated EPC – the worst grade possible.
Most properties across the west fringes of the country are not suitable for cavity wall insulation due to the fact they are highly exposed to wind and driven rain. This can cause problems with damp and mould in the walls and affecting the health of homeowners living in the dwelling.
Energy efficiency across the UK – the average cost of each EPC grade and how many houses received each grade
Everest gathered 7 example EPCs across the performance ratings to see the estimated energy costs of a dwelling for 3 years. The analysis shows there’s a drastic cost difference, between those with a C- and D-rated EPC (52%), and those rated F or G (35%).
External link
Energy in Demand - Sustainable Energy - Rod Janssen 
A very interesting survey. But I am curious that one of the worst performing places (Cornwall ) is a county. Unlike all the others listed , that means it is NOT a housing authority. Its statistics can only have been prepared by collating information from each of the four housing authorities within Cornwall. Why on earth has Everest bracketed all of them together?
You make a good point. EiD has no answer for why they bracketed all of them together.