The energy efficiency of new build homes
The home building industry is adapting at pace to support the country’s net zero targets and deliver increasing energy and thermal efficient homes.
In 2022, The Home Builders Federation released its first 'Watt a Save'
report comparing the energy performance of new build homes with older properties.
The report found that the home building industry collectively reduced household carbon emissions by 500,000 tonnes and help to save households up to £2,200 in annual energy costs.
HBF continues to examine the potential cost savings and energy efficiency of new build homes in line with quarterly government EPC data and changes to national energy costs.
The latest energy efficiency figures
Last updated: January 2024
Calculations are based on the Ofgem price cap from January 2024, using data from EPC registrations of new and existing properties in the year to 30 December 2023.
New build homes emit 61% less carbon a year
The average new build home emits 1.39 tonnes of carbon per year, just 39% of that of the average older property, which emits an average of 3.53 tonnes per year.
85% of new builds have an A or B EPC rating
New build homes are increasingly more energy efficient. Less than 5% of existing older properties achieve an A or B Energy Performance Certificate rating (EPC).
Making energy bills 55% cheaper
The average new build home is powered by 55% less energy, cutting energy bills by up to £184 a month. That's an annual saving of more than £2,200.
Energy usage per property type
Average reduction in energy usage
New build homes use 57% less energy than older counterparts, cutting the average energy bill by £137 a month. The average new build house uses 66% less energy than older houses.
Under the new Part L regulations, new build homes built from June 2023 will use just 31% of the amount of energy that the average existing property uses.
Calculations are based on Government's EPC registrations data of new and existing properties in the year to 30 December 2023.
| Existing | New build | Part L | |
|---|---|---|---|
| All properties | 20547 |
9156 | 6409 |
| Houses | 24195 | 8869 | 6209 |
| Flats | 13535 | 8199 | 5684 |
| Maisonettes |
17443 | 7643 | 5350 |
| Bungalows | 20153 | 9895 | 6927 |
Average annual energy use (KwH/PA)
Average energy use per m2
Critics of new build homes often suggest new properties are more energy efficient as they are smaller. EPC data evidences that this isn't the case, with new build homes using significantly less energy per m2.
| Existing | New build | % Saving | |
|---|---|---|---|
| All properties | 241.6 |
102.8; | 57% |
| Houses | 239.3 | 81.1 | 66% |
| Flats | 240.5 | 132.5 | 45% |
| Maisonettes |
235.2 | 103.3 | 56% |
| Bungalows | 272.4 | 104.6 | 62% |
Average carbon savings
New build homes emit 61% less carbon than older counterparts, cutting annual emissions by 2.16 tonnes per property.
The average new build house emits 65% less carbon than older houses. Buyers of new build homes in 2023 reduced carbon emissions by 500,000 tonnes.
New homes built from June 2023 under Part L will emit 73% less carbon than older homes, a saving of over 2.5 tonnes per property each year.
Energy bill savings by property type
Average monthly energy bill savings
The average new build home buyer saves £137 a month on energy bills, amounting to £1,640 a year, compared with purchasers of equivalent older properties. This saving rises to £184 per month for purchasers of houses, rather than flats or bungalows, totalling £2,200 a year.
Properties built from June 2023 onwards - to Part L regulations - will see an average saving of over £2,000, rising to £2,600 for houses specifically.
Prices are based on Ofgem’s price cap for January 2024, using Government's EPC registrations data of new and existing properties in the year to 30 December 2023.
| Existing | New build | Annual saving | Monthly saving | % saving | Part L | Part L annual saving | Part L % saving | |
|---|---|---|---|---|---|---|---|---|
| All properties | £2,958.70 |
£1,318.45 | £1,640.31 | £136.69 | 55% | £922.92 | £2,035.85 | 69% |
| Houses | £3,484.02 | £1,277.18 | £2,206.84 | £183.90 | 63% | £894.03 | £2,589.99 | 74% |
| Flats | £1,949.08 | £1,169.19 | £779.89 | £64.99 | 40% | £894.03 | £2,589.99 | 74% |
| Maisonettes |
£2,511.76 | £1,100.62 | £1,411.14 | £117.60 | 56% | £770.43 | £1,741.33 | 69% |
| Bungalows | £2,902.09 |
£1,424.95 | £1,477.14 | £123.10 | 51% | £997.46 | £1,904.63 | 66% |
Average annual energy costs (£)
Watt a Save reports
HBF issued Watt a Save reports from October 2022 to July 2023. Now, we maintain and update figures in line with statistical data releases. These updates are available in real time, on this page.
HBF's July 2023 Watt a Save report found new build homebuyers were saving over £400 million a year in energy bills, as well as collectively reducing carbon emissions by over 500,000 tonnes.
It showed the average new build homebuyer could save £135 a month on energy bills, amounting to more than £1,600 a year, compared with purchasers of equivalent older properties. This saving rose to over £180 per month for purchasers of houses, rather than flats or bungalows, totalling £2,200 a year.
Our February 2023 Watt a Save Report found new build properties are significantly more environmentally friendly than older equivalent properties, emitting just 1.4 tonnes of carbon a year, compared to the 3.6 tonnes that existing properties emit.
Download the reportOur first Watt a Save report found new build home buyers were saving an average of more than £2,000 on household bills per property each year, equivalent to £173 a month. For buyers of houses, as opposed to flats the savings were even greater at £220 per month.
Download the reportMember resources
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