The Isles of Scilly is the local authority with the least energy efficient homes in England and Wales, with a median score of 49, reveals analysis of 23 million EPC certificates by Uswitch.com, the comparison service.

Uswitch’s ranking of 331 local authorities revealed that Wales makes up five of the ten of the local authorities with the least efficient homes. All of the areas with the hardest to heat homes have scores of 62 or below.

Single-glazed windows, uninsulated walls and roofs, and electric room heaters are common problems that push up the cost of heating inefficient homes.

Table: Ten local authorities with least energy efficient homes

Rank

Local Authority

Number of addresses

Median energy efficiency score

1

Isles of Scilly

649

49

2=

Gwynedd

32,068

58

2=

Ceredigion

20,915

58

4

Isle of Anglesey

19,706

60

5

Pendle

24,383

61

5=

Eden

16,134

61

5=

Carmarthenshire

45,020

61

8

West Devon

14,674

62

8=

Southend-on-Sea

47,650

62

8=

Powys

35,276

62

Source: Uswitch.com.

Flats and maisonettes are the most energy-efficient homes in general, with park homes and bungalows commonly seeing greater heat loss. New-build homes are much more likely to have a higher EPC rating due to good insulation, and some even have solar panels and heat pumps pre-installed.

Five of the best-performing local authorities in the country are in London, led by Tower Hamlets, with homes scoring 74 on average for energy efficiency. New flats have been built in many parts of the capital in recent years, which may have pushed up the average score in those areas.

Table: Ten local authorities with most energy efficient homes

Rank

Local Authority

Number of addresses

Median energy efficiency score

1

Tower Hamlets

102,340

77

2

City of London

4,545

74

3=

Salford

92,126

72

3=

Southwark

86,598

72

5=

Cambridge

36,738

71

5=

Greenwich

75,853

71

5=

Hackney

75,877

71

5=

Milton Keynes

75,101

71

9=

Knowsley

46,339

70

9=

Basingstoke and Deane

43,195

70

Source: Uswitch.com.

Uswitch.com encourages households to check their home’s EPC certificate online, and see what improvements they could make to save money and energy.

Natalie Mathie, energy expert at Uswitch.com, comments: “The Isles of Scilly is a beautiful part of the UK, but its older housing stock unfortunately means residents are losing a lot of heat through uninsulated walls and roofs.

“Modern new-build properties need to meet more stringent efficiency standards, which may be why London boroughs have scored highly in the ranking. Every bit of heat that escapes your home will cost you money, so it’s worth knowing how efficient your home is.

“Take a moment to look up your home’s EPC certificate online and see where your property could be improved – the reports are incredibly detailed and will give you estimated costs for all the energy-saving measures. You can’t always tell if these changes are making a difference until you see your bill – unless you track your usage.

“People using the Utrack app can see the impact on their bills with hourly graphs, comparing gas and electricity use by day, week, month and year.”