EPC band C: 161,000 rented homes face limits to energy upgrades

What happened

EPC band C may be beyond the reach of an estimated 161,000 privately rented homes even if landlords complete every improvement recommended on their energy certificates, according to Houseprice.AI. Its analysis, reported by Landlord Today on 22 October 2026, highlights properties whose recorded potential rating remains below C. That is a different problem from a landlord simply not having carried out recommended work.

The figures point to a particular concentration in several London boroughs. Houseprice.AI puts the proportion of private lets unable to reach C at 19% in Tower Hamlets and 18% in Southwark. The figure is 16% in each of Lambeth, Westminster, Hackney and Haringey, according to the report.

The company examined official energy certificate records covering 21.2 million homes in England and Wales. It found that 53% of privately rented homes were below band C, equivalent to 1.9 million properties, compared with around a third of social homes. The 21.2 million figure therefore describes the wider register analysed, not the number of private rental properties in the study.

Houseprice.AI also identified 55,000 private lets with ratings of F or G. Those ratings fall below the band E minimum letting standard described in the report, making them a separate issue from homes that meet E but fall short of C. The published account does not establish whether those properties have valid exemptions, so the figure alone is not a count of unlawful lettings.

The background

An Energy Performance Certificate, or EPC, grades a home's energy performance from A to G and includes recommendations for improvements. It also records a potential rating associated with recommended work. Houseprice.AI's estimate of homes unable to reach C rests on those certificate recommendations, rather than a fresh technical assessment of every property.

That distinction limits how the findings should be read. A recorded potential rating below C indicates that the certificate's improvement pathway does not get the property to that level; it does not independently test every possible building alteration or heating system. The source does not say that surveyors visited the 161,000 properties to establish an absolute physical limit.

Landlord Today's account describes a requirement for private landlords in England to bring homes to band C by 2030, with exemptions available where the standard cannot be reached. However, it does not set out the detailed regulations, qualifying conditions or evidence needed for an exemption. The geographical distinction also matters: the analysis covers England and Wales, while the deadline is described specifically in relation to England.

Energy upgrades can involve insulation, heating and other changes to a building, but the suitable combination depends on the property. Work on traditional buildings can require particular care over materials and moisture, a subject explored in coverage of the planned traditional building retrofit centre in Falkirk. Houseprice.AI's published findings do not identify which construction types account for the homes with potential ratings below C.

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What people are saying

Houseprice.AI presents the findings as a local as well as a national problem, using council-level tables and regional figures. According to the company, private renters in rural areas face the weakest current performance, with only around one in four or one in five private lets reaching band C. That measures today's ratings, rather than the share that could reach C after improvements, so it should not be treated as the same measure as the London figures.

The report also puts a household cost against the difference between ratings. At the price cap used in its comparison, it estimates annual heating, hot water and lighting costs of about £2,080 for a band E home, against £1,020 for a band C home of the same size. The estimated difference is £1,060 a year, although the comparison is not a prediction of any individual tenant's bill.

The source says the gap would widen under a forecast rise of around a fifth in January's price cap. It does not identify the forecast provider or give revised annual costs for either rating. That projected increase should therefore be distinguished from the comparison at the price cap used in the analysis, rather than presented as a confirmed future charge.

The published account contains no named spokesperson's comments or government response explaining how the exemption arrangements would work. It also gives no estimate of how many landlords would apply successfully, or the cost of improving homes that can reach C. Separate initiatives, including the £10m backing announced for Warmer Homes London in 2025, provide context on upgrade support but do not establish eligibility for properties in this study.

What happens next

For a landlord assessing an individual property, the useful starting point is the certificate itself: its current rating, potential rating and recommended measures. A borough-wide percentage cannot show whether a particular flat or house can reach C. Where a certificate indicates a shortfall, property-specific professional advice can help distinguish what the recorded recommendations cover from work that would need further assessment.

The analysis does not provide a budget for bringing the 1.9 million homes currently below C up to that level. Owners therefore cannot use the national total to calculate their own upgrade costs or assume that a particular measure will deliver the required rating. Coverage of retrofit finance schemes offered in 2024 explains earlier funding approaches, but it is not confirmation that those products remain available or would suit a particular landlord.

Exemptions are the next important distinction between a low potential rating and a property's legal position. The source says landlords whose homes cannot reach C can register an exemption, but it does not specify the application process, duration or supporting evidence. A certificate showing potential below C should not, on that account alone, be treated as proof that an exemption has been granted.

For tenants, the bill comparison provides a reason to examine energy performance alongside rent when considering a home. Actual spending also depends on heating use, occupancy and energy prices, so an EPC rating is not a guaranteed annual bill. The report's exemption route means some tenants could remain in homes below C after 2030; it does not say how many households would ultimately be in that position.

Why this matters

Houseprice.AI's findings separate two questions for landlords: whether a home needs improvements and whether its recorded upgrade options can deliver band C. For tenants, the report suggests exemptions could leave some homes below that standard after 2030, with energy costs remaining an important consideration alongside rent. The practical issue is property-specific evidence. Neither a national estimate nor a borough percentage establishes what work an individual home needs, what it will cost or whether it qualifies for an exemption.