Your EPC Rating Matters More Than Ever
Installing an air source heat pump is one of the most impactful single changes you can make to improve your EPC rating. In many cases, it moves a property from Band D or E up to Band B or even Band A — a transformation worth 10–15% on property value according to Savills research. The SAP methodology assigns an efficiency of 300%+ to a heat pump (COP 3.0+), versus approximately 89–92% for a gas boiler, which drives a typical improvement of 15–25 SAP points from the heating system change alone. For landlords, it is also the most effective route to meeting the proposed MEES Band C requirement by 2028.
Related reading: How much does a heat pump cost in 2026? | Is your home suitable for a heat pump?
What Is an EPC?
An Energy Performance Certificate rates the energy efficiency of a building on a scale from A (most efficient) to G (least efficient). The rating is based on a Standard Assessment Procedure (SAP) calculation that considers:
- The building fabric: walls, roof, floor, windows, and doors — how well they retain heat
- The heating system: what fuel it uses, how efficient the boiler or heat pump is, and the type of controls
- Hot water: how it is generated and stored
- Lighting: the proportion of low-energy lighting
The SAP calculation produces a score from 1 to 100 (higher is better), which maps to the letter bands:
| EPC Band | SAP Score | Typical Property |
|---|---|---|
| A | 92–100 | New-build with heat pump, excellent insulation |
| B | 81–91 | Well-insulated home with heat pump or modern systems |
| C | 69–80 | Average modern home with gas boiler, good insulation |
| D | 55–68 | Typical 1960s–1990s home with gas boiler |
| E | 39–54 | Older home, poor insulation, ageing boiler |
| F | 21–38 | Very poor efficiency, minimal improvements |
| G | 1–20 | Worst performing, usually derelict or unimproved |
The average EPC rating for existing UK homes is Band D (SAP score around 60–65). Most homes built before 2000 with a standard gas boiler sit in the D or E range.
How a Heat Pump Improves Your EPC
The heating system is one of the most heavily weighted factors in the SAP calculation. Switching from a gas boiler to an air source heat pump delivers a significant improvement because:
1. Higher SAP efficiency rating
A modern gas condensing boiler is rated at approximately 89–92% efficiency in SAP terms. An air source heat pump is assigned a much higher efficiency — typically 300% or more (reflecting its COP of 3.0+). This improvement in the heating system efficiency score is the primary driver of EPC improvement.
2. Elimination of fossil fuel
SAP applies carbon emission factors to different fuel types. Electricity has a lower carbon factor than gas in the current SAP methodology (SAP 10.2), which further benefits the EPC score when you switch from gas to an electric heat pump.
3. Hot water improvement
If your heat pump also provides your hot water (as most do), the hot water element of the SAP calculation also improves. A heat pump with a well-insulated cylinder is significantly more efficient than a gas boiler for hot water production.
Real EPC Improvement Examples
Here are three representative scenarios based on typical properties in the Richmond, Kingston, and Twickenham areas:
Example 1: 1970s three-bedroom semi-detached
| Factor | Before (Gas Boiler) | After (Heat Pump) |
|---|---|---|
| Current EPC Band | D (SAP 62) | B (SAP 83) |
| Heating system | Gas combi boiler (89% eff.) | ASHP (COP 3.2, SAP 320%) |
| EPC improvement | D to B (+21 SAP points) |
In this case, the heat pump alone — with no other changes — moved the rating from D to B. The walls, loft, and windows were already reasonable, so the heating system was the main limiting factor.
Example 2: 1930s three-bedroom terrace
| Factor | Before (Gas Boiler) | After (Heat Pump + Loft Top-Up) |
|---|---|---|
| Current EPC Band | E (SAP 46) | C (SAP 71) |
| Heating system | Old gas boiler (78% eff.) | ASHP (COP 3.5, SAP 350%) |
| Loft insulation | 100mm (thin) | 300mm (topped up) |
| EPC improvement | E to C (+25 SAP points) |
Here the starting point was lower due to solid walls and single glazing. The heat pump plus a simple loft insulation top-up (approximately £400) achieved a jump from E to C.
Example 3: 2005 four-bedroom detached
| Factor | Before (Gas Boiler) | After (Heat Pump + Solar PV) |
|---|---|---|
| Current EPC Band | C (SAP 72) | A (SAP 94) |
| Heating system | Gas combi boiler (91% eff.) | ASHP (COP 3.5, SAP 350%) |
| Solar PV | None | 4 kWp system installed |
| EPC improvement | C to A (+22 SAP points) |
This newer property already had good fabric performance. Adding a heat pump and solar panels pushed it into Band A.
Related reading: Solar panels and heat pumps: the perfect combination
The Value Premium: What a Better EPC Is Worth
Savills research (2024)
Savills found that homes rated EPC A–C sell for 5 to 15% more than equivalent properties rated D or below:
- Homes rated A–B commanded an average premium of 10–15% over Band D equivalents
- Homes rated C commanded an average premium of 5–8% over Band D equivalents
- The premium was largest in higher-value markets — exactly the areas we serve (south-west London, Surrey)
What that means in practice
For a property worth £500,000 at Band D:
| EPC Improvement | Estimated Value Premium | Additional Value |
|---|---|---|
| D to C | 5–8% | £25,000–£40,000 |
| D to B | 10–15% | £50,000–£75,000 |
| D to A | 12–15% | £60,000–£75,000 |
A heat pump installation costing £10,000–£14,000 (or just £2,500–£6,500 after the BUS Grant, subject to eligibility) that moves your EPC from D to B could add £50,000 or more to the value of your home.
Growing buyer demand
Estate agents report that EPC ratings are now one of the first things serious buyers check, particularly younger buyers who have experienced the cost of poorly insulated homes as renters.
MEES Regulations: Why Landlords Need to Act
Current rules (2026)
The Minimum Energy Efficiency Standards (MEES) currently require all rented properties in England and Wales to have a minimum EPC rating of Band E. It is illegal to grant a new tenancy or renew an existing tenancy on a property rated F or G.
Proposed changes
The government has proposed tightening MEES to require a minimum of Band C for all new tenancies from 2028 and all existing tenancies from 2030. While the exact timeline may shift, the direction of travel is clear — landlords will need to improve their properties to Band C or face being unable to let them.
What this means for landlords
If your rental property currently sits at Band D or E, a heat pump installation combined with basic fabric improvements (loft insulation, draught-proofing) can transform it into Band B or C in a single project. The BUS Grant is available to landlords as well as owner-occupiers (subject to eligibility), making the economics very attractive.
Related reading: Landlord’s guide: heat pumps, EPC, and MEES
Getting a New EPC After Installation
Once your heat pump is installed, you will want an updated EPC to reflect the improvement. Here is the process:
- Commission the assessment with a qualified Domestic Energy Assessor (DEA). This typically costs £60–£120 and takes about 45 minutes.
- Provide documentation — have your MCS certificate for the heat pump installation, product data sheet showing the heat pump’s COP, and hot water cylinder details ready for the assessor.
- Receive the new EPC — lodged on the EPC Register within a few days, valid for 10 years.
We recommend getting the new EPC done within a month of installation. Some lenders and schemes require an up-to-date EPC, so having it ready avoids delays.
Combining Improvements for Maximum EPC Gain
| Measure | Typical SAP Improvement | Approximate Cost |
|---|---|---|
| Air source heat pump | +15 to +25 points | £2,500–£6,500 (after BUS Grant, subject to eligibility) |
| Loft insulation top-up (to 300mm) | +3 to +8 points | £300–£500 |
| Cavity wall insulation | +5 to +12 points | £500–£1,500 |
| Solar PV (4 kWp) | +5 to +10 points | £5,000–£7,000 |
| LED lighting throughout | +1 to +3 points | £50–£200 |
Green Mortgages and Financial Products
A better EPC rating unlocks access to preferential financial products:
- Green mortgages: Several UK lenders (Barclays, Nationwide, NatWest) offer lower interest rates or cashback for properties rated A–C. Savings of 0.1–0.2% on mortgage rates can amount to thousands over the mortgage term.
- Green home loans: Specialist finance products for energy improvements often require a target EPC of C or above.
- Insurance discounts: Some insurers are beginning to offer reduced premiums for energy-efficient homes.
How Electromatic Can Help
Electromatic M&E Ltd offers free home surveys across London and Surrey (TW, KT, SW postcodes). We handle BUS Grant applications (subject to eligibility), install ASHP and solar PV from a single contractor, and deliver within 2–4 weeks of survey confirmation. All work is carried out under MCS certification via our accredited umbrella partner. We provide the MCS certificate your Domestic Energy Assessor needs to record the heat pump correctly on the EPC Register.
Call us: 07718 059 284 | Email: admin@electromatic.uk
Frequently Asked Questions
How many EPC bands can a heat pump improve?
Typically one to three bands, depending on your starting point and the existing fabric of the property. A move from D to B (two bands) is very common for a home that already has reasonable insulation and double glazing. Properties starting at E or F may need additional measures alongside the heat pump to reach Band B, but a jump to Band C is almost always achievable with the heat pump alone.
Do I need a new EPC before and after installation?
You need a valid EPC before installation if you are applying for the BUS Grant — this is a requirement (subject to eligibility criteria set by Ofgem). After installation, getting a new EPC is optional but strongly recommended, as it reflects the true performance of your home and is essential if you plan to sell or remortgage.
Does a heat pump improve the EPC more than a new gas boiler?
Significantly more. Replacing an old gas boiler with a new condensing boiler might improve your SAP score by 5–10 points. Replacing it with a heat pump improves the score by 15–25 points. The difference is substantial because the SAP methodology recognises the dramatically higher efficiency and lower carbon emissions of a heat pump.
Will the EPC methodology change in future?
SAP 10.2 is the current standard. SAP 11 is expected to be introduced in the coming years and is likely to further favour low-carbon heating systems like heat pumps while penalising fossil fuel systems more heavily. Installing a heat pump now positions your property well for both current and future EPC assessments.
Can I challenge an EPC rating if it seems too low?
Yes. If you believe the assessor has made an error — for example, not correctly recording your heat pump or insulation — you can raise a complaint with the assessor’s accreditation body. Having your MCS certificate and product documentation to hand helps avoid errors in the first place.
The information in this article is for general guidance only and does not constitute financial, legal, or technical advice. EPC improvement estimates are illustrative and based on SAP 10.2 methodology. Actual improvements depend on your property’s specific characteristics, existing fabric, and the heat pump specification. Property value estimates are based on Savills research (2024) and may not reflect your specific market. The Boiler Upgrade Scheme (BUS) grant of £7,500 is subject to eligibility criteria set by Ofgem — not all properties qualify. MEES proposed changes are subject to government policy and may change. Electromatic M&E Ltd operates under MCS certification via our accredited umbrella partner. All installations comply with Building Regulations Part L and MCS standards. E&OE.
Written by Electromatic M&E Ltd — ASHP & Solar installer, London & Surrey (electromatic.uk)
Last updated: April 2026 | Electromatic M&E Ltd, Company No. 13837345
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