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.
We continue to examine the energy efficiency of new build homes in line with quarterly government EPC data and changes to national energy costs.
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The latest energy efficiency figures
Last updated: January 2025
With the move to the electrification of new build properties, it has become more complex to track bills based on energy usage and unregulated energy. As such, the below now quantifies the savings new builds offer with respect to regulated energy – heating, hot water and lighting.
Calculations are based on the Ofgem price cap from October 2024, using data from EPC registrations of new and existing properties in the year to 30 September 2024.
New build homes emit 65% less carbon a year
The average new build home emits 1.22 tonnes of carbon per year, just 35% of that of the average older property, which emits an average of 3.51 tonnes per year.
86% 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 heating, hot water and lighting costs 50% cheaper
The average new build house owner will pay just over £800 a year for these utilities, compared to £1,789 for those in older properties. This is a yearly saving of £979.
Average carbon savings
On average, new build properties emit 65% less carbon than older counterparts, cutting annual emissions by 2.29 tonnes per property.
The average new build house emits 67% less carbon than older houses. Buyers of new build properties in 2024 reduced carbon emissions by 500,000 tonnes.
Energy bill savings by property type
Average energy bill savings
On average, new build homeowners could save more than £64 a month on their heating, hot water and lighting bills, amounting to £780 a year, compared with purchasers of older properties. This saving rises to £82 per month when comparing the energy performance of houses specifically, rather than flats or bungalows, totalling over £979 a year.
Critics might argue the savings are owing to new builds being smaller. However, this is not the case. The average newly built home is 89m2 compared with an average of 86m2 for older properties.
Prices are based on Ofgem’s price cap for October 2024, using Government's EPC registrations data of new and existing properties in the year to 30 September 2024.
NB: These are the regulated energy costs as estimated based on EPC performance data.
EPC ratings data
EPCs of new build and existing homes in the year to September 2024
86% of new build homes achieved the highest levels of energy performance (A or B EPC) compared with less than 5% of older homes.
Calculations are based on Government's EPC registrations data of new and existing properties in the year to 30 September 2024.
Watt a Save reports
HBF issued Watt a Save reports from October 2022 to July 2023.
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.
Download reportOur 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.
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