Severn Wye CEO Sandy Ruthven explains why achieving better energy efficiency in residential properties is at the heart of the UK’s transition to a more sustainable and climate-friendly future – and why progress so far is worryingly slow.
With fuel bills still some of the highest in decades and our homes accounting for 26% of the UK’s carbon emissions, home energy efficiency matters to all of us. But I’m sad to say the Office of National Statistics (ONS) latest figures for energy efficiency in our homes show little has changed since last year.
Energy performance and the pound in your pocket
First, a word about EPCs. The energy performance certificate is a standard assessment of a property’s energy efficiency, rated on a scale from 0 to 100. This score determines the home’s EPC band, ranging from A (most efficient) to G (least).
An uplift in your EPC band is not just a number on paper; it can translate into tangible savings.
Take Rightmove’s May 2025 figures, right: they make for stark reading. Clearly efficiency is not just an environmental objective but a financial one as well.
Simply put, this shows that people living in the least efficient homes (incidentally also often those on the lowest incomes) are paying thousands more for their energy bills than they need to.
Still below the threshold
So, what does the ONS say? The median EPC score for homes in England stands at 68, while in Wales it is slightly lower at 67. Both scores fall within band D, signalling that most homes are still below the threshold considered highly energy efficient (band B or above). While these scores represent the median – meaning half of all homes are less efficient and half are more – it is clear there is significant room for improvement. And things haven’t been changing fast enough: the scores have risen just two points in the last ten years.
There are some glimmers of hope though.
Promising trends
One of the most promising trends in recent years is the gradual improvement in the efficiency of new dwellings. Over the five years leading up to 2024, new homes in both England and Wales achieved a median EPC score of 84 (band B), up from 82 in England and 81 in Wales for the five years to 2014. It tells us that legislation and regulation do make a difference – but so far they have not been particularly tough so the difference isn’t big enough. So that begs the question: why isn’t regulation on energy efficiency for new builds more stringent: surely all new homes should be a band A?
Our government needs to step up and make sure we are not building homes that need retrofitting before they are even occupied.
But there is some good news for those living on the lowest incomes – social rented homes are forging ahead in energy efficiency. In England, the median EPC score for this tenure type is 70, while in Wales it is even higher. This is welcome and indicates that public policy and investment in the social housing sector are paying dividends in terms of energy performance. This is something Severn Wye has played a role in by supporting social housing companies to retrofit homes and we are proud of the difference we have made to support people living on low incomes.
Uptake of district heat networks
One statistic that really jumped out at me is the number of London homes heated by district networks – 75% of new homes have centrally generated heat that is distributed to multiple buildings. These systems are usually much better in terms of efficiency and emissions, particularly when combined with low-carbon generation. The rapid uptake of this type of network in London can be attributed to a combination of local policy incentives, urban density, and the higher proportion of new, large-scale developments; outside the capital, however, only about 5% of new homes benefit from district heating and the limited adoption elsewhere highlights the challenge of retrofitting decentralised heating solutions in more dispersed and rural settings.
So, energy efficient homes really are the key structural change we can make to cut carbon emissions, reduce bills and improve the comfort and resilience of our homes as our climate changes. Limited regulation and investment from government so far means the improvements are not nearly extensive enough and far too many people continue to pay high prices and live in cold homes. The government’s Warm Homes Plan to invest £13bn in improving energy efficiency is welcome, but with consultation and planning still underway we are still waiting to see meaningful change.
