An Energy Performance Certificate (EPC) rates your home's energy efficiency on a scale from A (most efficient) to G (least efficient). Understanding your EPC can help you reduce energy bills and increase property value.
EPC Rating Bands
What Each Rating Means
| Rating | Description | Typical Energy Cost |
|---|---|---|
| A | Exceptional efficiency, new builds with solar/heat pump | £500-700/year |
| B | Very efficient, modern well-insulated homes | £700-1,000/year |
| C | Average efficiency, typical new build standard | £1,000-1,400/year |
| D | Below average, typical older property | £1,400-1,900/year |
| E | Poor efficiency, minimum rental standard | £1,900-2,500/year |
| F | Very poor, cannot legally let as private rental | £2,500-3,200/year |
| G | Worst efficiency, very expensive to heat | £3,200+/year |
Energy costs are estimates for a typical 3-bed semi-detached house at 2024 energy prices.
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When You Need an EPC
- Selling a property: Must have valid EPC before marketing
- Renting a property: Must provide to tenants, minimum E rating required
- After building: New builds need EPC on completion
- ECO scheme applications: For energy efficiency grants
Minimum Energy Efficiency Standards (MEES)
Private rental properties must meet minimum EPC requirements:
| Date | Requirement |
|---|---|
| Now (2020 onwards) | All new and existing tenancies must be E or above |
| Proposed 2028 | All rentals must be C or above (subject to confirmation) |
How to Improve Your EPC Rating
Quick Wins (Low Cost)
| Improvement | Typical Cost | Rating Improvement |
|---|---|---|
| Loft insulation (270mm+) | £300-500 | +5-10 points |
| Hot water cylinder jacket | £15-30 | +1-2 points |
| LED lighting throughout | £50-150 | +1-3 points |
| Draught proofing | £100-200 | +1-2 points |
| Heating controls upgrade | £200-400 | +2-4 points |
Medium Investments
| Improvement | Typical Cost | Rating Improvement |
|---|---|---|
| Cavity wall insulation | £500-1,500 | +5-15 points |
| New condensing boiler | £2,000-3,500 | +5-10 points |
| Double glazing (full house) | £4,000-10,000 | +5-10 points |
| Floor insulation | £500-1,000 | +2-5 points |
Major Upgrades
| Improvement | Typical Cost | Rating Improvement |
|---|---|---|
| Air source heat pump | £8,000-15,000 | +10-20 points |
| Solar panels (4kW system) | £5,000-8,000 | +5-15 points |
| External wall insulation | £8,000-15,000 | +10-20 points |
| Ground source heat pump | £15,000-35,000 | +10-25 points |
Government Grants Available
ECO4 Scheme
Free or subsidised insulation and heating for eligible households:
- Receiving certain benefits (Universal Credit, Pension Credit, etc.)
- EPC rating D, E, F or G
- Can cover loft, cavity and solid wall insulation
- Heating system upgrades
Boiler Upgrade Scheme
- £7,500 off air source heat pump
- £7,500 off ground source heat pump
- £5,000 off biomass boiler (rural areas)
- Must have valid EPC with no outstanding recommendations for loft or cavity wall insulation
Understanding Your EPC Report
Your EPC includes:
- Current rating: Your property's current efficiency
- Potential rating: What it could achieve with improvements
- Estimated energy costs: Current and potential bills
- Recommendations: Specific improvements with cost estimates
- Environmental impact: CO2 emissions rating
Example: D to C Improvement
Current rating: D (58)
Potential rating: C (75)
Improvements needed:
- Loft insulation top-up: £300 → +4 points
- New condensing boiler: £2,500 → +7 points
- Smart heating controls: £350 → +3 points
- LED lighting: £100 → +2 points
Total cost: £3,250
Annual savings: £400-500
Payback: 6-8 years
How to Get an EPC
- Find an accredited assessor on the EPC register
- Book an assessment (usually £60-120)
- Assessor visits for 30-60 minutes
- EPC generated within 1-3 days
- Certificate valid for 10 years
EPC Impact on Property Value
Research shows properties with higher EPC ratings command premium prices:
- EPC A/B properties can sell for 3-5% more
- EPC F/G properties may sell for 5-10% less
- Buyers increasingly prioritise energy efficiency
- Lower running costs make properties more attractive
How EPC Assessments Are Calculated
EPC assessments follow the Standard Assessment Procedure (SAP), which is the UK government's methodology for calculating the energy performance of dwellings. The assessor inputs details about your property into approved software, which generates the energy rating based on the building's characteristics rather than how the occupants actually use it. This means that your EPC rating reflects the theoretical energy performance of the building fabric and fixed systems, not your actual energy bills.
The assessment considers multiple factors including wall construction type and insulation levels, roof insulation thickness, floor construction, window glazing type and age, the main heating system type and efficiency, hot water system, lighting, and any renewable energy generation. The assessor will examine the property for approximately 30 to 60 minutes, taking measurements, checking loft insulation depth, identifying boiler age and model, and noting the type and condition of windows and doors. They may also check the property's age and construction type against standard assumptions if physical inspection is not possible for certain elements.
One important aspect that homeowners should understand is that the EPC score is calculated per square metre of floor area. This means that larger properties can sometimes achieve better ratings than smaller ones with the same features, because fixed energy demands such as heating the hot water cylinder are spread across more floor space. Conversely, very small properties may receive lower ratings than expected despite good insulation and efficient heating, simply because the energy demand per square metre is proportionally higher.
UK Energy Efficiency in Context
The UK has some of the oldest and least energy-efficient housing stock in Europe. Approximately 29 percent of UK homes were built before 1919, many with solid walls that are expensive and complex to insulate. The average EPC rating for existing UK homes is Band D, with a score of around 60. Only about 3 percent of homes achieve an A or B rating, while approximately 10 percent are rated F or G. The UK government has set a target for as many homes as possible to reach EPC Band C by 2035, a goal that requires significant investment in retrofitting the existing housing stock.
Energy efficiency improvements offer substantial savings at current energy prices. Following the energy price increases of 2022 and 2023, the financial case for improving home efficiency has strengthened considerably. Moving from Band D to Band C can save approximately £300 to £500 per year on energy bills, while moving from Band E to Band C could save £700 to £1,000 annually. These savings mean that many efficiency improvements now have payback periods of five to ten years, after which the savings continue for the lifetime of the improvement.
The Warm Homes Plan, announced in 2024, aims to provide additional support for homeowners looking to improve energy efficiency. Combined with the existing Boiler Upgrade Scheme and ECO4 programme, there are now multiple pathways for UK homeowners to access financial support for energy efficiency improvements. Consulting with a qualified energy advisor or your local council's energy team can help identify which grants and schemes you are eligible for based on your property type, current EPC rating, and household income.
Frequently Asked Questions
Can I challenge my EPC rating if I think it is wrong?
Yes, you can lodge a complaint if you believe your EPC assessment contains errors. Contact the accreditation scheme that the assessor belongs to, which will be named on the EPC certificate. Common errors include the assessor recording the wrong boiler type, missing insulation that was present, or using incorrect property dimensions. If the complaint is upheld, a new assessment will be conducted at no cost to you. You can also simply commission a new EPC from a different assessor if you believe the original was inaccurate, though you will need to pay the assessment fee again.
Does an EPC rating affect my mortgage application?
While EPC ratings do not currently prevent mortgage approval, they are becoming increasingly relevant to lending decisions. Several UK lenders, including Barclays, NatWest, and Nationwide, offer preferential mortgage rates or cashback incentives for properties with high EPC ratings, typically A or B. The Bank of England has also signalled that climate-related risks, including energy efficiency, may factor into future lending criteria. Properties with very low EPC ratings may become harder to sell or mortgage as regulations tighten.
How long does an EPC assessment take and what does it cost?
A typical EPC assessment takes 30 to 60 minutes for a standard three-bedroom house, though larger or more complex properties may take longer. The cost ranges from £60 to £120 depending on property size, location, and the assessor chosen. The resulting certificate is valid for 10 years. You can search for accredited assessors through the official EPC register website and compare prices. It is worth noting that the cheapest assessor may not always provide the most thorough assessment, so checking reviews and ensuring they will physically inspect all accessible areas of the property is advisable.
What grants are available in the UK to improve my home's energy efficiency rating?
Can landlords be fined for having a low EPC rating in England and Wales?
How much does it cost to improve an EPC rating from Band D to Band C in the UK?
Emma Thompson
Senior Content Editor
Emma is a senior content editor with a background in financial journalism. She specialises in making UK regulations and calculator tools understandable for consumers, working closely with qualified professionals to ensure accuracy.