With the energy price cap due to rise in January 2024, we have explored who might find it more difficult to heat their homes. To do this, we have used data from energy performance certificates (EPCs) and household information from Census 2021.

Of homes with an EPC, around 8 million homes in England (58%) and 460,000 in Wales (62%) were rated below band C. We have used this as a threshold for a low energy efficiency home, in line with UK government targets for fuel-poor homes to meet this standard by 2030.

We found that households with older adults and those with multiple generations living in them were disproportionately likely to be living in these lower energy efficiency homes. A home with lower energy efficiency may be harder to keep warm and more expensive to heat.

Keeping homes warm enough is particularly important for certain groups, including older people.

However, living in a low energy efficiency home is not automatically a sign of financial vulnerability over winter, with owner-occupied homes and detached homes both more likely to have lower energy efficiency.

People aged 65 years and over were less likely than other age groups to report finding it difficult to afford energy bill payments, according to data from our Opinions and Lifestyle Survey collected between July and October 2023. However, they were more likely than some younger age groups to report cutting back on gas and electricity usage because of the rising cost of living.

Around 40% of all properties across England and Wales did not have an EPC by 2021, meaning they haven’t been included in this article. As EPCs are only required when a house is let or sold, certain types of homes are more likely to fall into this category.

Other breakdowns of homes' energy efficiency by household characteristics such as employment type, ethnicity, religion, and vehicle ownership are included in our associated data tables.

What is an energy performance certificate?

A domestic energy performance certificate (EPC) provides a snapshot of your property’s overall energy efficiency and carbon dioxide (CO2) emissions. It can give an indication of how much your heating, lighting, and use of various common appliances might cost.

EPCs are based on data and assumptions about properties collected by approved domestic energy assessors, who then use government-approved modelling software to produce a score typically ranging from 0 to 100. This normally ranks a property from A to G, with A being the most energy efficient. Homes with lower energy efficiency scores may be harder to keep warm and more expensive to heat, particularly during the winter months.

Homes are only legally required to have an EPC if they are being sold or rented out, so many properties (over 11 million) across England and Wales do not have one, and a home’s energy efficiency may have changed since its latest EPC. Households with no EPC are an unknown quantity and do not necessarily have lower energy efficiency.

An EPC is valid for 10 years. Our data include the latest EPC a property has, even if it is more than 10 years old.

Homes with people aged 65 years and above more likely to have lower energy efficiency

Census 2021 data contain information on the ages of people living in homes, as well as household composition. These data, when matched with energy performance certificate (EPC) data, showed homes with older age groups tended to have lower energy efficiency.

Of homes with EPCs, those where at least one, but not all residents were aged 65 and over were more likely to have lower energy efficiency than homes where all residents were aged 65 years or over.

Around 7 in 10 homes where at least one, but not all, people were aged 65 and over across England and Wales had lower energy efficiency (67.7% in England and 69.6% in Wales).

By contrast, this reduced to about 6 in 10 homes where all residents were aged 65 years or over (59.4% in England and 62.8% in Wales).

Homes where all occupants were aged under 65 years were the least likely to have lower energy efficiency (57.3% in England, and 60.8% in Wales).

People aged 65 years and over more likely to live in homes with lower energy efficiency

Proportion of homes with EPC rated below band C, and age of residents in 2021

Embed code

Download the data for homes with EPC C or below and age of residents (XLSX, 21KB)

Census 2021 data shows older people are more likely to own their own home. This also related to energy efficiency, with owner-occupied homes more likely to have lower EPC ratings. More research is needed to confirm the extent of this relationship.

Multi-generational homes more likely to have lower energy efficiency

We can look more closely at each of these groups, by looking at the ages of the rest of the household occupants. Overall, multi-generational households (those with members across at least three different generations) were most likely to live in homes rated below band C.

Around 7 in 10 multi-generational households (69.3% in England and 70.2% in Wales), with a mixture of children (aged 0 to 15 years), people of working age (aged 16 to 64 years), and people aged 65 and above lived in homes with lower energy efficiency.

Among households with some people aged 65 years and over, those whose other members were all aged 15 years or younger were the least likely to live in homes with lower energy efficiency (63.1% of these households in England, and 61.4% in Wales).

In England, homes where people were all working age were the least likely to have lower energy efficiency (56.2% of homes). In Wales, homes with people of working age and children were the least likely to have poor energy efficiency (60.5%).

Homes with three generations living in them most likely to have lower energy efficiency

Proportion of homes with EPCs rated below band C and household composition in 2021

Embed code

Download the data for homes with EPC C or below and age of residents showing generational breakdowns (XLSX, 21KB)

We also used information gathered in Census 2021 on household composition to create a similar snapshot of the types of families living in homes on census day that have different EPC ratings.

Homes with people who were all aged 66 years and above more likely have lower energy efficiency

Over 700,000 homes in England and more than 45,000 homes in Wales with energy performance certificates (EPCs) were single-family households where everyone was aged 66 years and over.

These households were more likely to have lower energy efficiency on census day compared with other household types, with two thirds of these households in England (65.9%) and almost 7 in 10 in Wales (69.2%) living in homes rated below band C.

Although households known to have exclusively older occupants account for a minority of the population in England and Wales (close to one in five households in both countries), they are disproportionately likely to have lower energy efficiency compared with other household types.

People aged 66 years and over most likely to live in homes with lower energy efficiency

Proportion of homes with EPCs by rating and household composition in 2021

Embed code

Download the data for homes with EPC C or below and household composition (XLSX, 21KB)

Just over half (52.8%) of the 3.8 million single person homes with EPCs had lower energy efficiency, making this the household type least likely to live in a home with an EPC rating of below band C.

In Wales the households least likely to live in homes with low energy efficiency were those occupied by a single person or lone parents. This accounted for over 330,000 households, of which around 57% were living in homes rated below band C.

It is important to note that Census 2021 household composition data does not tell us the precise age ranges of people in these other household types, and people aged 66 years and over might live in them, alongside people in other age groups.

Older people most likely to report cutting energy usage amid cost-of-living pressures

Homes with lower energy efficiency may be harder to keep warm making them more expensive to heat, which has a direct impact on households struggling with the cost of living. As the winter weather starts to bite, rising living costs leave many people with difficult choices to make.

Around two-thirds (69%) of adults in Great Britain who said their cost of living had increased in the last month reported their gas and electricity bills had increased, according to data from the latest Opinions and Lifestyle Survey (15 to 26 November 2023).

Further analysis of Opinions and Lifestyle Survey data from 12 July to 1 October 2023 allowed us to look in more detail at which groups have been most affected by the rising cost of living across Great Britain. We found that groups including lone parents (75%), renters (60%), disabled adults (54%), and Black, African, Caribbean or Black British adults (58%) were more likely to report it was difficult (very difficult or somewhat difficult) to afford their energy payments.

Notably, though people aged 65 years and above were less likely than those in other age groups to report finding it difficult to afford their energy payments, around 6 in 10 people (59%) aged 65 years and above did report cutting back on household fuel like gas or electricity. This appeared higher than in younger age groups with around a quarter (27%) of those aged 16 to 29 years, around 4 in 10 (42%) of those aged 30 to 49 years and 56% of those aged 50 to 64 years reporting this.

Analysis of Census 2021 health data and Census 2021 disability data has already shown the proportion of people across England and Wales who said they had bad or very bad health, or were considered disabled, increases with age. This means that some people in these older age groups who live in less energy efficient homes and are using less fuel to cope with the cost of living, may be at greater risk of various adverse outcomes associated with colder homes.

Homes should ideally remain at a constant temperature of at least 18 degrees Celsius to reduce the risk of adverse outcomes like various health problems associated with the cold, according to advice published by the Met Office. Some of these outcomes can include “a wide range of health conditions, especially respiratory and cardiovascular, as well as poor mental health and unintentional injury”, according to a report by the Institute for Health Equity.

Reducing energy use to cope with increasing living costs in homes with poorer energy efficiency may be particularly dangerous for vulnerable groups like young children, people aged 65 years and over, and people with reduced mobility or underlying health conditions.

People living in flats and socially rented accommodation less likely to have hard-to-heat homes

Not all people in these vulnerable groups live in homes with lower energy performance certificate (EPC) ratings. We know factors such as age, tenure, construction, and size are important in the energy efficiency of a home, and previous research has also found that the age of a property is the biggest factor in its energy efficiency.

For example, some of these people may live in properties like flats, maisonettes, and apartments which are known to typically have better energy efficiency. A substantially smaller proportion of people lived in homes like these which had ratings below band C.

Flats, maisonettes, and apartments most likely to have better energy efficiency

Proportion of homes with EPCs rated below band C and accommodation type in 2021

Embed code

Download the data for homes with EPCs below band C by accommodation type (XLSX, 14KB)

Homeowners and private renters are also far more likely to live in homes with lower energy efficiency than people living in social rented properties.

Around 7 in 10 homes whose residents own their properties outright (68.0% in England and 73.0% in Wales) lived in properties with lower energy efficiency.

Though people aged 65 years and over are more likely to own their homes outright, some may live in these more energy efficient homes, including social rented properties.

Social rented accommodation far more likely to have better energy efficiency

Proportion of homes with EPCs rated below band C and tenure in 2021

Embed code

Download the data for homes with EPCs rated below band C by tenure (XLSX, 17KB)

Homes with multiple ethnicities or religions more likely to have lower energy efficiency

Our data tables include information on energy performance certificate (EPC) ratings of homes by a range of other household characteristics.

Homes with a mixture of three or more ethnic groups were most likely to have lower energy efficiency, as were homes with any combination of three or more religions.

Homes with multiple vehicles were more likely to have lower energy efficiency.

Larger proportions of homes with a mixture of people who were employed, unemployed, or economically inactive were less energy efficient.

Homes heated by solid fuel (including coal) were highly likely to have lower energy efficiency, yet homes heated by district or communal heat networks were far more likely to have better energy efficiency.

Further breakdowns of energy efficiency ratings by characteristics such as household size, heating type, occupation, and occupancy are included in our associated data tables.

To find out more about energy efficiency read the GOV.UK guidance on saving energy in your home. You can also phone the Energy Saving Advice Service on 0300 123 1234 or Home Energy Scotland on 0808 808 2282.

You can find out more about support from government, including support with energy bills and household costs this winter, on the Help for Households webpage.

View all data used in this article