The UK’s capital city is the most energy efficient region in Britain, according to new data published on Wednesday.
The Office for National Statistics (ONS) said London had the highest median energy efficiency out of all English regions, while Yorkshire and the Humber and the West Midlands had the lowest average score.
The factors that were taken into consideration to determine energy efficiency included property type, tenure and when the building was constructed.
Energy Performance Certificates (EPCs) indicate the energy efficiency of buildings. First introduced in 2007, they are based on data about a building's energy features, for example, the building materials used, the heating systems and insulation.
These are collected by an accredited energy assessor and entered into a government-approved software to generate a score for the EPC, typically ranging from 0 to 100. Domestic EPCs are banded from A to G, where A is the most energy efficient.
EPC assessments also include an environmental impact score based on expected carbon dioxide (CO2) emissions. The higher the rating, the less impact it has on the environment.
The ONS revealed that the median energy efficiency score for dwellings in England was 66 and 64 in Wales for all records up to March 2021, which is equivalent to band D. London had an average score of 68, while the West Midlands was 65.
The data also showed that flats and maisonettes were the most energy efficient property type in both England and Wales, with a median energy efficiency score of 72, equivalent to band C. Detached dwellings scored the lowest in Wales (62), whilst in England, detached and semi-detached (63) were joint lowest.
“This may be because of external wall exposure being higher in detached properties, compared with flats and maisonettes that are more likely to be grouped in blocks,” the ONS said.
From a tenure point of view, social rented dwellings had the highest median energy efficiency score across all property types in both England and Wales. Owner-occupied dwellings scored the lowest in both England and Wales with a score of 62 and 60, respectively.
However, one of the main contributors to energy use in the home is central heating, with different sources seen as more or less energy efficient.
As of March 2021, some 79% of dwellings with an EPC analysed in England used mains gas to fuel central heating, and 78% in Wales.
Electricity was the second most common fuel type used to fuel central heating in England (12%). In Wales, oil and electricity (both around 8%) were joint second.
Among English regions and Wales, the North East had the highest estimated proportion of dwellings that used mains gas (87%) and London the lowest (69%).
London also had the highest proportion using community heating schemes (16%), around six times that of any other region.
Watch: Energy crisis could derail global economy says IEA