If you own, let, or build property in the UK, the rules for proving how energy-efficient your building is are about to change in a way they haven’t changed in over a decade. Out goes the single A-to-G rating most of us grew up with on the back of estate agent brochures. In comes a three-metric system — Fabric Performance, Heating System, and Smart Readiness — and getting your head around it now will save you serious money later. This guide explains what each metric actually measures, when the changes kick in, and what landlords and developers should be doing in 2026 to stay ahead of it. No jargon, no hand-wringing — just the facts and what to do with them.
What is changing with EPCs in 2026?
The government published its Warm Homes Plan in January 2026 and, alongside it, the response to two long-running consultations on EPCs and the Minimum Energy Efficiency Standard (MEES). The headlines were everywhere — EPC C by 2030, £10,000 cost cap, fines up to £30,000 — but underneath those headlines is something more fundamental: the way an EPC actually rates a building is being rebuilt from the ground up.
The old methodology, called SAP for new builds and RdSAP for existing homes, produced one number on a scale from A to G. From the second half of 2027 (delayed from late 2026), a new methodology called the Home Energy Model, or HEM, will start producing EPCs with three separate metrics instead of one. The legacy single-rating system will run alongside it until October 2029, then disappear.
In short: by October 2030, every private rented home in England and Wales will need to be the equivalent of EPC C — but ‘equivalent’ now means meeting the standard on multiple metrics, not just one overall score.
The three new EPC metrics
Here is what each one measures and why it matters.
1. Fabric Performance
Fabric Performance is about the building itself — the walls, the roof, the floor, the windows, and how airtight the whole envelope is. It measures how well the structure holds onto heat, independent of what’s bolted to the boiler or fitted on the roof. Think of it as the thermal quality of the actual bricks and mortar.
This metric is the one most landlords with older properties should worry about. A solid-wall Victorian terrace in north London can have the most efficient heat pump on the market and still fail Fabric Performance because heat is pouring out through the walls. Improving this metric means insulation, better windows, sealing the building envelope, and reducing thermal bridging at junctions — exactly the kind of work U-value calculations and air tightness testing exist to verify.
2. Heating System
This metric scores the efficiency and carbon intensity of how you heat the building. A gas boiler — even a top-of-the-range condensing one — will be capped at band D under this metric. To hit band C on the Heating System route, you’ll need a heat pump, a connection to a low-carbon heat network, or something equivalent. If your property already has a heat pump, brilliant — this is probably your easiest route to compliance. If you have a gas boiler and replacing it isn’t realistic, you’ll need to route through the Smart Readiness metric instead. More on that next
3. Smart Readiness
Smart Readiness measures how well a building can interact with the grid and respond to changing energy conditions. In practice that means things like solar PV, battery storage, smart meters, electric vehicle charge points, and the controls that let those systems talk to each other.
This is the route a lot of landlords with gas heating will end up taking. Adding solar PV plus a smart meter can be considerably cheaper than ripping out a working boiler and replacing it with a heat pump, especially on terraced properties where heat-pump installations are more complex.
How compliance actually works under the new system
This is where it gets specific. Under the rules confirmed for the Private Rented Sector, a property must meet band C on the Fabric Performance metric as the primary standard. After that, the landlord chooses one secondary metric — either Heating System or Smart Readiness — and must also hit band C on that one.
For the Social Rented Sector, the rules are slightly different: landlords meet one metric of their choice by April 2030, and a second metric of their choice by April 2039. The flexibility is more generous, but the direction of travel is the same.
If a property already holds a valid EPC at band C under the current methodology when the cut-off arrives, it will be treated as compliant until that certificate expires. This is significant — it means an EPC commissioned today, under the current SAP/RdSAP rules, can buy you up to ten years of compliance under the new regime.
The cost cap and what counts towards it
The cost cap for the Private Rented Sector is £10,000 per property. Spend up to that amount, and if the property still doesn’t reach band C, you can register a ten-year exemption. For properties valued below £100,000, the cap drops to 10% of the property value under the new Property Value Adjustment rule.
Two things to know that aren’t in the headlines. First, eligible spending from 1 October 2025 onwards counts towards the £10,000 — so improvement work you do now can be tallied later. Second, the cost of the EPC itself counts towards the cap, which is a small detail but worth keeping receipts for.
The fine for letting a non-compliant property after the 2030 deadline is up to £30,000 per breach. The government deliberately set that high to make sure ignoring the rules is more expensive than complying with them.
What landlords should do in 2026
There are five practical things worth doing this year, in roughly this order.
First, find out what your current EPC actually says. If it expired or you’ve never had one, get one done. An EPC issued under the current methodology before October 2029 will be valid for ten years and may carry you all the way to 2035 or beyond before you need a HEM-based one.
Second, if your current rating is D or below, don’t wait. The most cost-effective improvements — loft insulation, draught-proofing, hot water cylinder jackets, low-energy lighting, smart thermostats — are usually under a few hundred pounds each and can shift a property up a full band. Doing this work in 2026 means you can lock in a C rating under the old system and have a decade of breathing room.
Third, get realistic about your route to compliance. If you have a gas boiler and a tight budget, plan for the Smart Readiness route: solar PV, smart meter, ideally a battery. If you have an opportunity to replace the heating anyway, a heat pump is the cleaner long-term answer.
Fourth, if you have a portfolio of properties, prioritise the worst performers. The properties currently at E or F will eat the biggest share of your £10,000 caps, and they’re the ones most likely to need a new EPC under HEM after 2029.
Fifth, keep your paperwork. Receipts, installer certificates, photos of insulation before plasterboard goes back up, commissioning data from heating engineers. When the new EPCs arrive and an assessor needs to score your property, evidence of what’s behind the walls is gold.
What developers and architects need to know
For new builds and major refurbishments, the immediate concern is making sure designs are fit for HEM rather than just current SAP. The two methodologies aren’t wildly different in what they reward — both like good insulation, airtight construction, and efficient heating — but HEM is more granular, and design choices that just scrape through under SAP may not be comfortable under HEM.
Specifically, watch thermal bridging at junctions (your PSI values), overheating risk if you’re working in London where TM59 is mandatory, and the choice of heating strategy. A gas boiler in a new build is now effectively a dead-end specification — Part L compliance is one thing, but a heat pump or heat network gives the building a future-proofed Heating System score from day one.
If you’re commissioning SAP or SBEM calculations now, ask your assessor whether the design has been stress-tested against the draft HEM metrics. Most accredited firms — ours included — are already running parallel calculations to flag designs that look fine under SAP but would struggle under HEM.
H2: Frequently asked questions
Will my existing EPC still be valid in 2030?
Yes. EPCs issued under the current methodology remain valid for ten years from the date of issue. If your existing EPC shows a C or better and it was issued before October 2029, your property is treated as compliant under MEES until that certificate expires.
Do I need a new EPC in 2026 just because the rules are changing?
No. You only need a new EPC at the usual triggers — sale, new let, major refurbishment — or when your existing one is about to expire. If you’re planning improvement works, though, commissioning a new EPC under the current methodology can lock in a favourable rating and buy you time under the transition rules.
H3: What happens if my property can’t reach band C even after £10,000 of work?
You can register a ten-year cost-cap exemption. The property remains lettable during that period, after which the position will be reviewed. The Property Value Adjustment also reduces the cap on lower-value homes — a property valued under £100,000 only needs spending equivalent to 10% of its value.
My property is a listed building — am I exempt?
Heritage exemptions have been tightened significantly. Being listed is no longer an automatic out — you’d need to show that specific energy-efficiency measures would unacceptably alter the building’s character, and that case has to be evidenced. Many listed properties can still reach C through internal insulation, secondary glazing, and improved heating, especially with the cost cap to back it up.
I’m in Scotland or Northern Ireland — does this apply to me?
The rules confirmed in January 2026 apply to England and Wales. Scotland operates its own EPC regime under the Scottish Government, and Northern Ireland under the Department of Finance. The direction of travel — higher minimum standards, new metrics — is the same, but the timelines and specific rules will be different. Check the relevant national guidance for your jurisdiction.
The bottom line
The new EPC metrics aren’t designed to catch landlords out — they’re designed to produce a more accurate picture of how buildings actually perform. Fabric Performance rewards good construction. Heating System rewards low-carbon heat. Smart Readiness rewards flexibility on the grid. Read together, the three of them are how the UK plans to get its housing stock to net zero, one property at a time.
If you’re a landlord or developer, the worst thing you can do is wait until 2029 to find out where you stand. Get a current EPC if you don’t have one. Plan your route — Heating System or Smart Readiness. Spend smart, document everything, and keep an eye on the band-boundary announcements expected once the consultation closes.
If you’d like a clear, fixed-fee assessment of where your property sits today and what it would take to hit a confident C rating under both the current and new methodologies, that’s exactly the conversation our accredited team has every day. Send us your address and a couple of photos and we’ll come back within two hours with honest numbers — no obligation, no upsell.
Get a fixed-fee EPC and compliance plan
ARMEEC is Elmhurst, ABBE, ECMK and City & Guilds accredited and has been helping UK developers and landlords meet building compliance since 2010. Whether you need an EPC today, SAP calculations for a new build, or a full review of a portfolio against the 2030 standard, we can help.
Call 020-area number — sorry, the actual contact line — on +44 7816 587548, or use the quote form on this page. We respond within two hours during business hours.