"Changes to Minimum Energy Efficiency standards and EPC reform are on the horizon for 2026 and will impact landlords differently depending on their property portfolio"
- Michael Davey - OSB Group
The Energy Performance Certificate (EPC) regime is undergoing change, with significant consultations from the Government in 2025, but did you know that some changes have already happened?
In June, the procedure, called Reduced Data Standard Assessment Procedures (RdSAP), used to calculate EPC ratings for existing dwellings was updated. This means if you now commission an EPC for one or more of your properties, it will be assessed against the updated procedure. The adjustments address some of the friction points experienced with the previous version.
RdSAP 10 recognises newer technologies like heat pumps, uses more up-to-date carbon factors, and has improved modelling of heating systems and insulation. Whilst progress is generally positive, better reflecting the reality of a property, the changes will inevitably alter ratings, sometimes upwards, sometimes downwards, bringing both risk and opportunity for landlords.
What this means for landlords
The current Minimum Energy Efficiency Standards Regulations require properties to have an EPC rating of at least E in order to be legally let or be registered for an exemption. If you need a new EPC because, for example, the current one has expired and you intend to market, sell or let the property, the assessment will take place using the new procedure.
Properties that might have met the minimum standard or EPC E or above previously could slip, particularly those reliant on older gas boilers or electric heating. Conversely, homes with renewables or modern insulation may benefit.
Below are some of the potential winners and losers under RdSAP 10, followed by some tips to get the most out of the assessment should you need one.
(Potential) winners under the new Standard Assessment Procedure
· Electric-heated properties – significant uplift thanks to cleaner grid electricity than previous and less of a penalty compared to gas.
· Heat pumps – much stronger recognition of their efficiency, could move properties up a band.
· Renewables – solar PV, battery storage, and smart heating controls are rewarded.
· New-builds and well-insulated properties – better and more detailed modelling highlights benefits to performance of the building’s fabric (walls, windows, roofs etc.)
· LED lighting – not ‘new’ news, but now positively factored in.
(Potential) losers under the New Standard Assessment Procedure
· Gas-heated properties – Gas boilers now score less favourably relative to electric heating or heat pumps.
· Poorly insulated homes – If you can’t evidence insulation exists or the airtightness of a building, you will score poorly in the thermal performance area.
· Lack of paperwork – missing evidence (e.g. glazing certificates, insulation warranties, boiler documents) defaults to conservative assumptions, reducing ratings.
· Properties with storage heaters – old electric heating without modern controls still scores poorly, despite grid decarbonisation
So, what can landlords do?
Although you can’t change the rules, you can ensure the property is represented in the best possible light:
· Gather documentation: provide certificates, invoices, or warranties for insulation, glazing, heating upgrades, and renewables. Without documented evidence, assessors could default to a set of assumptions that understate the property's performance.
· Provide access: ensure lofts, basements, meter and boiler cupboards are clear and accessible. If assessors cannot see or test, they might record “unknown,” which lowers scores.
· Show them what you’ve got: highlight the improvements that have been made that might be less visible, such as underfloor insulation, pipe lagging, or smart heating controls; all of these help maximise the score.
· Check the lightbulbs: assessors still check if low-energy lighting is installed.
Changes to Minimum Energy Efficiency standards and EPC reform are on the horizon for 2026 and will impact landlords differently depending on their property portfolio. Those who prepare well, maintain documentation, and invest strategically in energy efficiency measures will be best positioned to manage regulatory risk, protect asset value, and meet growing tenant expectations.
