Government has delayed the Home Energy Model (HEM), the new way EPCs will be calculated, to the second half of 2027. The proposed 2030 EPC C standard has not moved with it. And there is a catch most landlords have not spotted: a C rating under the current system is not guaranteed to remain a C under the new one.
Two things worth being clear on before you spend anything. First, band C for rented homes is a government proposal, not law. The minimum in force is band E and has been since 1 April 2020, band D is legal to let, and the band C standard needs primary legislation followed by a statutory instrument amending the Energy Efficiency (Private Rented Property) (England and Wales) Regulations 2015. None has been laid. Second, an almost identical proposal was announced and then scrapped in September 2023.
That does not mean do nothing. It means spend on things that pay off under either outcome.
This guide gives a framework based on your property and situation rather than blanket "act now" or "wait" advice.
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 Proposed 2030 Date Has Not Moved
The HEM delay does not change the October 2030 date government has proposed for landlords to reach EPC C. The NRLA made the same point in March 2026: the delay does not change the announced timeline for Minimum Energy Efficiency Standards.
Announced is the operative word. The date is a policy intention with roughly four years of runway if it survives the legislative process. Nothing obliges you to reach C today.
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 have not been finalised. The NRLA has warned that a C rating under today's system is not guaranteed to remain a C under the reformed framework.
In plain terms: a property that reads as C now could read as something else once the new metrics arrive, without anyone touching it.
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 commentators have suggested that heat pumps or solar may be needed for some property types to achieve C under HEM. Nothing is confirmed in the final metrics, so treat that as informed speculation rather than a planning assumption.
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, and window upgrades are the safest spend right now. Government has indicated the Fabric Performance element of HEM is likely to remain broadly similar to the current approach, and fabric measures cut running costs whatever the methodology says.
The NRLA has made the same point: starting with fabric improvements is a sensible approach. It counts under the current system and is likely to count under HEM.
Spending from October 2025 would count toward the proposed cap
Government has proposed that landlord spending from 1 October 2025 onwards counts toward a proposed £10,000 per-property cost cap. Neither the cap nor the start date is law: the cap in force is £3,500 including VAT, measured against band E, and only your own spending counts toward it. Grant money does not.
If you are planning fabric work anyway, doing it now is the low-regret option, and keeping the receipts costs nothing.
Your EPC expires before 2030
EPCs are valid for 10 years. If your current certificate expires before October 2030, you will need a new one under whatever methodology is in place at the time. There is a case for getting a fresh assessment under the current system to establish a baseline, though it will not lock in anything under HEM.
You're close to C with cheap interventions
If you are 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 is a strong case for acting now. Band D is legal to let, so this is a choice rather than an obligation, but low-cost fabric-first work is safe under both methodologies and cuts bills either way. 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 to £15,000 installed, and the 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 the final band boundaries are published in H2 2027. Spending on a heat pump you turn out to need is fine. Spending on something else first and then needing the heat pump anyway is not.
Your upgrade spend is approaching the cap
If you have already spent, or plan to spend, close to the cap on heating-system upgrades, pause. Should HEM require different heating measures, you could exhaust your cap allowance on work that carries less weight in the new framework.
The cap is per property. You do not get a second allowance.
You've recently received an EPC C
If you have just been assessed at C under RdSAP and the property is a standard mid-terrace with a gas boiler, you are compliant now and comfortably above the band E minimum. Do not assume the C is permanent under a new methodology. Book a review once the HEM metrics are finalised.
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 cap with an uncertain HEM route | Wait, don't exhaust the cap on measures that may not carry weight |
| EPC expires before 2030 | Review now, renew or plan the 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 how it holds up under the Heating System metric |
| Spending already incurred since Oct 2025 | Track it, document everything |
What the NRLA and Government Are Saying
The NRLA's position, published in March 2026, is that this is an important window for landlords and that starting with fabric improvements is a sensible approach. It has also pointed out that continued delays prolong uncertainty for landlords who want to invest but lack clarity on the standard they will eventually have to meet.
The government's January 2026 partial response to the EPB reform consultation set out its intentions: band C by 1 October 2030, a £10,000 cost cap, and HEM replacing the current Energy Efficiency Rating. Those are stated intentions. The legislation that would give them effect does not exist yet.
The practical translation: do not let uncertainty paralyse you, and do not treat a proposal as a bill you have already been sent. Fabric improvements are a safe bet on both counts. 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?
The delay to HEM does not change the October 2030 date government has proposed for band C. That date is a proposal rather than a legal deadline, and what is actually in force is band E, so nobody letting a D-rated property is breaking the law today. If you intend to reach C, four years is comfortable and the last year will not be. 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 has warned that a C under today's system is not guaranteed to remain a C under the reformed framework. How you reached C matters: a property that got there through fabric improvements is more likely to hold its rating than one leaning on a gas boiler score. The final HEM band boundaries are expected 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 cost cap?
Under the proposals, landlord spending from 1 October 2025 onwards would count toward a proposed £10,000 per-property cap. That is not law. The cap in force is £3,500 including VAT, measured against band E, and only your own spending counts: grant money does not, so a measure funded through ECO4 or the Boiler Upgrade Scheme leaves your allowance intact. Document every receipt either way.
The bottom line: do not let the delay become an excuse for inaction, and do not treat a proposal as a deadline. Fabric improvements are safe under any methodology. Heating decisions are not, so hold off until the HEM metrics are confirmed. Know how your current EPC reached its band, check when it expires, and keep the receipts for everything 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.