EPC reform, and the four metrics arriving in October

Everybody knows what an EPC looks like. A coloured bar chart, a letter from A to G, and a list of recommendations most people never read. That certificate is being taken apart.

The government's Warm Homes Plan, published on 21 January 2026, set the direction, and the partial response to the Reforms to the Energy Performance of Buildings regime consultation, published in March 2026, confirmed the mechanics. The target date for the new-style certificate is October 2026.

From one letter to four metrics

The current EPC reduces a building to a single Energy Efficiency Rating, which is a cost-based measure. That has always been the criticism of it. A property with poor walls and a cheap heating fuel can score better than a well insulated one with expensive heating, which tells you something about tariffs rather than something about the building.

The replacement reports four metrics rather than one: energy cost, fabric performance, heating system, and smart readiness.

Fabric performance is the one to watch. It measures the building itself, the walls, the roof, the floors, the windows and the airtightness, independent of what is bolted to it. A heat pump in a leaky solid-wall terrace will no longer flatter the certificate.

The consultation response also confirmed the removal of the exemption that heritage buildings have relied on, which is a material change for anyone holding listed or conservation-area stock.

What the rented standard actually asks for

This is where the format change stops being administrative.

Under the Warm Homes Plan, every privately rented home in England and Wales has to meet an EPC C equivalent standard by 1 October 2030. The earlier proposal of a phased approach, 2028 for new tenancies and 2030 for existing ones, has been dropped. There is one date, and it applies to the whole sector at once.

The standard is not the old headline letter. Compliance is measured against two of the new metrics: fabric performance as the primary test, plus either the heating system metric or the smart readiness metric as a secondary, with the landlord choosing which of the two to be assessed on.

Read that again from a planning point of view. The primary test is the part of the building that is slowest and most disruptive to change, and the part you cannot fix in the final year.

The current minimum is band E. The gap between an E and a fabric-led C is not a lighting upgrade.

The cost cap, and the date that has already passed

Spending is capped at £10,000 per property. Where £10,000 would be 10% or more of the property value, a low-value exemption applies. Other exemptions cover cases where the work would damage the fabric or structure, where a third party withholds consent, and where all relevant improvements have already been made.

One detail is worth pulling out because it is quietly generous and quietly easy to lose. Improvements made from October 2025 count towards the cap. Work already done in the last ten months is creditable, if you can evidence it.

That is an invoice and specification problem, not an energy problem. A cavity fill done last winter, paid for and forgotten, is worth several thousand pounds of cap headroom to the landlord who kept the paperwork and nothing at all to the one who did not.

The maximum penalty for a breach rises to £30,000 per property.

The methodology moves too

There is a third date in the sequence. The assessment methodology switches from the current cost-based Energy Efficiency Rating to the Home Energy Model on 1 October 2029.

So the order runs: new certificate format from October 2026, new methodology from October 2029, compliance deadline on 1 October 2030.

The practical consequence is that an EPC produced today, and an EPC produced in 2031, are not measuring the same thing. Any portfolio-level plan built on current ratings is built on a scale that is being retired. Treat today's certificates as a rough sort of the stock, not as a compliance position.

What is worth doing now

The useful work in the next twelve months is mostly clerical, which is why it tends not to get done.

Find out what your walls are. Fabric performance turns construction type into the deciding variable. Solid wall, filled cavity, unfilled cavity, system build, and whether anyone has ever actually confirmed it rather than assumed it from the age of the property. This belongs on the property record as a field, not in the memory of whoever did the last survey.

Recover the evidence for work already done. Anything from October 2025 onwards counts against the cap. That means invoices, specifications, installer certifications and guarantees, filed against the property rather than against the year's accounts.

Log insulation and heating as assets. Loft insulation depth, cavity fill, glazing specification, the heat source and its controls are all things with an install date, a specification and a service life. They behave like assets because they are assets.

Sequence by construction type, not by current rating. The properties that need the longest lead time are the solid-wall ones, and they will not announce themselves in a band D. Trades capacity across two sectors on a single national deadline is the constraint that decides who finishes on time.

Do not wait for the new certificate to plan. The fabric does not change in October 2026. Only the way it is reported does.

Where this sits in SAMRISK

Energy performance is a records problem long before it is a retrofit problem, and it lives across several places at once.

Construction type, wall build-up and glazing specification sit as properties of the building in materials, so fabric is a queryable field across a portfolio rather than a line in an old survey PDF. Insulation, glazing, the heat source and its controls are assets in items with install dates, specifications and service intervals, and the servicing runs as recurring work in maintenance.

Certificates, invoices, installer sign-offs and guarantees belong in documents, attached to the property, which is what turns work done in 2025 into evidence in 2030. The assessment cycle runs through the compliance calendar so the next EPC is created when the last one expires, and the periodic condition sweep runs as an audit. Where a measure is specified but not yet installed, it is a task with an owner and a date, and the fabric detail attaches to the elevation in building plans.

The point

October 2026 changes the certificate. October 2030 is the one that changes the building.

The five years between them look comfortable and are not, because the primary metric is fabric, fabric work has long lead times, and every landlord in England and Wales is working to the same deadline with the same trades.

The cheapest thing you can do this year costs nothing to install. Write down what your buildings are made of, and keep the receipts for the work you have already paid for.

Sources: Department for Energy Security and Net Zero and Ministry of Housing, Communities and Local Government, Warm Homes Plan, published 21 January 2026, GOV.UK; DESNZ, Reforms to the Energy Performance of Buildings regime: government response (partial), March 2026, GOV.UK; Energy Efficiency (Private Rented Property) (England and Wales) Regulations 2015, as the standard currently in force at band E.