The government has just delayed the Home Energy Model (HEM) — the new way EPCs will be calculated — to the second half of 2027. The 2030 EPC C deadline hasn't moved. And there's a catch most landlords haven't spotted: a C rating under the current system is not guaranteed to remain a C under the new one.
So what do you actually do now?
This guide cuts through the confusion. Not "act now" or "wait" as blanket advice — but a clear framework based on your property and situation.
What Has Actually Changed (The Short Version)
The HEM Delay
On 9 March 2026, the government published an "outcome update" confirming the Home Energy Model had been pushed back from H2 2026 to H2 2027. The original plan was for HEM to run alongside the current Energy Efficiency Rating (EER) from late 2026, before fully replacing it on 1 October 2029.
That timeline has slipped by a year. The reason given: "engagement with industry on the delivery timeline."
The 2030 Deadline Isn't Moving
This is the critical point. The HEM delay does not change the October 2030 deadline for landlords to reach EPC C. That requirement stands. The NRLA confirmed this in March 2026: "The delay does not change the announced timeline for Minimum Energy Efficiency Standards."
You still have just under four years to get to C.
The EPC C Portability Problem
Here's what most landlords are missing. The new HEM uses a completely different methodology to calculate EPC ratings. Instead of the current single A–G rating based on SAP/RdSAP, it will use four metrics:
- Fabric Performance (insulation, windows, draught-proofing)
- Heating System (boiler type, heat pump, renewable)
- Smart Readiness (smart meter, controls)
- Energy Cost (running costs per year)
The scoring bands for each metric haven't been finalised. But the NRLA has already warned: "A C rating under today's system is not guaranteed to remain a C under the reformed framework."
In plain terms: you could be compliant today and non-compliant in 2027 when the new metrics kick in — without touching a thing.
Is Your Current EPC C Safe Under HEM?
This is the most important question you should be asking.
The honest answer is: it depends on how you got to C. Under HEM, the Heating System metric is weighted significantly — and a property that hit C under RdSAP via, say, a modern gas boiler and loft insulation may score differently when the heating element is assessed against a framework that specifically favours heat pumps and solar panels.
Industry observers, including The Independent Landlord, have noted that heat pumps or solar are likely to be required for some property types to achieve C under HEM. This hasn't been confirmed in final metrics yet (the consultation only closed on 18 March 2026), but it is a material risk for landlords making upgrade decisions now.
The key takeaway: if you have a current EPC C, don't assume it's done and dusted. Check when it was issued and whether your route to C was heating-heavy. The HEM outcomes article covers this in detail.
When to Act Now
Your upgrade involves fabric improvements
Insulation, draught-proofing, floor insulation, window upgrades — these are the safest upgrades to make right now. The government has indicated the Fabric Performance element of the new HEM methodology is likely to remain broadly similar to the current approach.
The NRLA's guidance is clear: "Starting with fabric improvements may be a sensible approach." If you're going to spend money, start here — it counts under the current system and is highly likely to count under HEM.
Costs from October 2025 count toward the £10,000 cap
Any qualifying improvement spending from 1 October 2025 onwards counts toward the per-property £10,000 cost cap. If you're planning upgrades anyway, starting now has a compound benefit: you hit compliance sooner and start the cap clock earlier.
Don't sit on fabric improvements just because HEM is delayed. The clock is already running.
Your EPC expires before 2030
EPCs are valid for 10 years. If your current certificate expires before October 2030, you'll need a new one under the HEM methodology anyway. In this scenario, there's a case for getting a new assessment under the current system to lock in your status and create a time buffer — but only if you're confident in your current rating's stability under the new framework.
You're close to C with cheap interventions
If you're currently rated D and a few hundred pounds of improvements (LED lighting, heating controls, draught-proofing) would tip you to C under the existing system, there's a strong case for acting now. Low-cost, fabric-first interventions are safe under both systems. Use our property cost estimator to check what the gap looks like for your property type.
When to Wait
You're weighing up a heat pump installation
This is the highest-risk decision to make before HEM metrics are finalised. Heat pumps are expensive (typically £8,000–£15,000 installed), and the government's proposed HEM framework gives significant weight to the Heating System metric.
If a heat pump is the marginal call that gets you to C under HEM, wait until H2 2027 when the final band boundaries are published. Spending £10,000 on a heat pump that you find you needed anyway is fine. Spending £6,000 on something else now and then needing a heat pump too is not.
Your upgrade spend is approaching the £10,000 cap
If you've already spent or are planning to spend near the £10k cap on heating-system upgrades, pause. If the current interventions don't transfer under HEM — or if HEM requires different heating measures — you may find you've exhausted your cap budget on work that doesn't count in the new framework.
The cap is per property. You don't get a second shot.
You've recently received an EPC C (in the last 1–2 years)
If you just got an EPC C under RdSAP and your property is a standard mid-terrace with a gas boiler, you're probably fine short-term. But don't assume your C is permanent. Book a review when HEM metrics are finalised in H2 2027 — before the October 2029 transition deadline.
Decision Framework: Quick Checklist
Use this to decide your next step:
| Your Situation | Action | |---|---| | Fabric work needed (insulation, windows, draught-proofing) | Act now — safe under both systems | | Heating system upgrade needed (heat pump, solar) | Wait — hold until HEM bands confirmed H2 2027 | | Near the £10k cap with uncertain HEM route | Wait — don't exhaust the cap on uncertified measures | | EPC expires before 2030 | Review now — renew or plan renewal timeline | | Close to C with low-cost fixes | Act now — cheap and low-risk under either system | | Currently EPC C via gas boiler only | Review — check sustainability under new Heating System metric | | Costs from Oct 2025 already incurred | Track spend — document everything toward the cap |
What the NRLA and Government Are Saying Right Now
The NRLA's official position, published 12 March 2026:
"This period arguably represents one of the most important windows of opportunity for landlords. Where possible, starting with fabric improvements may be a sensible approach."
The government confirmed in its January 2026 partial response to the EPB reform consultation: the 2030 deadline stands, the £10k cost cap is confirmed, and HEM will replace the current EER by 1 October 2029.
The key word in all of this is uncertainty. The NRLA acknowledged this explicitly: "Continued delays only prolong uncertainty for landlords who want to invest in improving their properties but still lack clarity about the standards they will ultimately be expected to meet."
The practical translation: don't let uncertainty paralyse you. Fabric improvements are a safe bet. Major heating decisions can wait for clarity.
For more on what the HEM means specifically for your property's rating, see our full guide: What Happens to Your EPC After the Home Energy Model.
Frequently Asked Questions
Does the 2027 delay mean I can wait until 2027 to start upgrades?
No. The 2030 deadline for EPC C hasn't changed. If you're currently rated D, E, F, or G, you still need to reach C before October 2030. The 2027 date refers to when the new HEM methodology launches — not when you need to comply. For the cheapest route from D to C, see our EPC D to C upgrade guide.
Will my current EPC C count under the new HEM system?
Not automatically. The NRLA explicitly warns: "A C rating under today's system is not guaranteed to remain a C under the reformed framework." How you got to C matters — a property that hit C through fabric improvements is more likely to hold its rating than one that relied solely on a gas boiler score. The final HEM band boundaries will be published in H2 2027.
Should I commission a new EPC assessment now before the metrics change?
Only if your current certificate is expiring before 2030 or you genuinely don't know where you stand. Getting a fresh RdSAP assessment now gives you a baseline, but it won't lock in your compliance under HEM.
What upgrades are safe to do now regardless of the new metrics?
Fabric improvements: loft insulation, cavity wall insulation, solid wall insulation, draught-proofing, double/triple glazing, floor insulation, and smart heating controls. The government has indicated the Fabric Performance element will remain broadly similar in HEM. Also LED lighting is universally safe and low cost. See cheapest ways to improve your EPC rating for the full list.
Does spending on upgrades now count toward the £10,000 cost cap?
Yes. Qualifying improvement costs from 1 October 2025 onwards count toward the per-property £10,000 spending cap. This means any safe fabric improvements you make now are already ticking down your cap liability. Document every receipt.
The bottom line: don't let the delay become an excuse for inaction. Fabric improvements are safe under any methodology. Heating decisions are not — hold off until HEM metrics are confirmed. Know your current EPC's exact route to C, check when it expires, and track every pound you spend from October 2025.
The sell or upgrade question is a separate decision entirely — but if you're upgrading, this is how you sequence it.