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 almost £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.

In this section

New build homes emit 61% less carbon a year

The average new build home emits 1.33 tonnes of carbon per year, just 39% of that of the average older property, which emits an average of 3.51 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 57% cheaper

The average new build home is powered by 57% less energy, cutting energy bills by up to £183 a month. That's an annual saving of almost £2,200 on new build houses.

Energy usage per property type

Average reduction in energy usage

When comparing all property types, new build homes use 57% less energy than older counterparts, cutting the average energy bill by £140 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 31 March 2024.

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.

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 energy bill savings

The average new build home buyer saves £140 a month on energy bills, amounting to £1,685 a year, compared with purchasers of equivalent older properties. This saving rises to £183 per month for purchasers of houses, rather than flats or bungalows, totalling almost £2,200 a year.

Properties built from June 2023 onwards - to Part L regulations - are estimated to save homeowners over £2,000 on their annual energy bills, rising to £2,575 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 31 March 2024.

Average annual energy costs (£)

Note: Part L savings are calculated again existing property data, i.e. % saving against older homes.

EPC ratings data

EPCs of new build and existing homes in the year to December 2023

85% 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 31 March 2024.

EPCs of New Builds vs existing data (kWh/PA)