Energy Advice
An EPC does not just produce a rating. It produces a recommendation report listing the measures that would improve it, in the order that achieves each step up the scale. That report is the cheapest energy advice you will get, and most people never read the second page.
Below: how to read the report, which measures actually move the number, what grant funding is currently available, and the three mistakes that waste the most money.
Start with the recommendation report
Every EPC is accompanied by a report showing recommended measures, an indicative cost for each, the typical annual saving, and the rating the property would reach afterwards.
The crucial detail is that the ratings are cumulative and assume the measures are installed in the order listed. The first rows are chosen because they are the cheapest route to the next band, not because they are the most impressive. A solid wall insulation job costing £14,000 may appear below a £20 lighting upgrade, because the lighting gets you further for less.
What actually moves a rating
The table below is drawn from the government’s own worked example. It illustrates the pattern rather than predicting your property — the actual figures depend on the building, its age and its current heating.
| Measure | Indicative cost | Typical annual saving |
|---|---|---|
| Room-in-roof insulation | £1,500 – £2,700 | £837 |
| Draught proofing | £80 – £120 | £18 |
| Low energy lighting | Around £20 | £21 |
| High heat retention storage heaters | £1,200 – £1,800 | £319 |
| Internal or external wall insulation | £4,000 – £14,000 | £195 |
| Double glazing (low-E) | £3,300 – £6,500 | £123 |
| Solar photovoltaic panels | £5,000 – £8,000 | £287 |
Two lessons follow. First, the cheapest measures are often the ones that shift the rating, because the calculation rewards reduced heat loss and better lighting whatever the age of the property. Second, the most expensive measures are not automatically the most effective — solid wall insulation saves less per pound than almost anything else on the list, and is usually a last resort rather than a first.
Where a property has an old non-condensing boiler, replacing it with a condensing unit and proper heating controls frequently produces one of the largest single gains available, for a fraction of the cost of the fabric work.
Grants and funding
Boiler Upgrade Scheme
The Boiler Upgrade Scheme provides a grant towards replacing a fossil fuel heating system in England and Wales. Current amounts:
| System | Grant |
|---|---|
| Air source heat pump | £7,500 |
| Ground source heat pump | £7,500 |
| Biomass boiler | £5,000 |
| Air-to-air heat pump | £2,500 |
Until March 2027 there is an additional £1,500 where the property is heated by oil or LPG and has no mains gas connection. It is one grant per property, the installer must be MCS certified, and they apply through Ofgem on your behalf — the grant is deducted from the quotation rather than paid to you.
Energy Company Obligation
ECO funding comes from energy suppliers rather than government and is aimed at low income and vulnerable households, and at homes with poor ratings. Eligibility depends on the property and on any benefits received, and the work is arranged through a participating installer rather than claimed afterwards.
For landlords
The minimum rating for rented property is band E, and the government has confirmed its intention to raise it to band C from 1 October 2030. Work done in stages, guided by the recommendation report, is usually far cheaper than a single job forced by a deadline. See EPC rules for private landlords for the dates, exemptions and penalties.
Three mistakes worth avoiding
- Doing the expensive measure first. Solid wall insulation or new glazing before loft insulation and draught proofing is the most common way to spend several thousand pounds for a smaller gain.
- Not re-issuing the certificate. The old EPC stays valid for ten years and keeps showing the old rating. If you need it to demonstrate compliance or support a sale, order a new assessment once the work is done.
- Assuming an exemption. Listed buildings in particular are exempt only where compliance would unacceptably alter their character — not as a blanket rule.
Frequently asked questions
What is the cheapest way to improve an EPC rating?
Usually loft insulation and low energy lighting, because both are inexpensive and affect the rating directly. Draught proofing and hot water cylinder insulation are similarly cheap. The recommendation report on your EPC lists measures in order of what would achieve the rating, so start there rather than with the largest job.
Does a new boiler improve an EPC rating?
Yes, and on older systems it can be one of the largest single gains, because the boiler efficiency figure feeds straight into the calculation. A modern condensing boiler with proper heating controls typically outperforms an old non-condensing unit by a wide margin.
Do I need a new EPC after making improvements?
The old certificate remains technically valid for ten years, but it will still show the old rating. If you are selling, letting, or need to demonstrate compliance, order a new assessment so the improvement is recorded.
Can I get a grant for a heat pump?
The Boiler Upgrade Scheme offers £7,500 towards an air source or ground source heat pump, £5,000 towards a biomass boiler and £2,500 towards an air-to-air heat pump in England and Wales. Until March 2027 there is an additional £1,500 where the property is off the gas grid and heated by oil or LPG.
How do I apply for the Boiler Upgrade Scheme?
Your installer applies on your behalf through Ofgem, and the grant is deducted from your quotation rather than paid to you. The installer must be MCS certified, and you can only claim one grant per property.
Does a listed building need an EPC to sell or let?
Often yes. The exemption applies only so far as meeting energy performance requirements would unacceptably alter the building character or appearance, which most listed dwellings can avoid. Assume a certificate is needed until an assessor has confirmed otherwise.
Next step
Book an EPC assessment Ask an advisor
Or call 0208 522 0001.
Sources: GOV.UK, Boiler Upgrade Scheme: what you can get; GOV.UK, Domestic private rented property: minimum energy efficiency standard — landlord guidance (sample recommendations table). Scheme rules and figures change — this page reflects the position in October 2026.