An EPC (Energy Performance Certificate) is a document that shows how energy-efficient a home is. Every property in the UK is given a rating from A to G, with A being the most efficient and G being the least. The rating is based on how much energy the property uses, how costly it is to heat, and how much carbon it emits.

EPC ratings are important because they give homeowners and installers a clear picture of how the home performs and what improvements are needed. A better EPC rating usually means the property is cheaper to heat, stays warmer for longer, and is more environmentally friendly.

How the EPC scale works

• A–B: Very energy efficient — new builds or homes with major upgrades
• C: Fairly efficient — modern homes or older homes with insulation
• D: Below average — common in many UK homes
• E–G: Poor efficiency — high heating bills and significant heat loss

Most UK homes fall somewhere between D and E. ECO4 focuses on improving homes rated D, E, F, or G, because these properties lose the most heat and cost the most to run.

What affects your EPC rating?

Several factors determine your EPC rating, including:

• Type and condition of your heating system
• Whether the loft and walls are insulated
• The age and type of windows
• How airtight the property is
• Whether you use renewable energy (like solar panels)

Even simple improvements — like better insulation — can move a property up one or two EPC bands.

Why EPC ratings matter for ECO4

ECO4 uses EPC ratings to decide which upgrades will have the biggest impact.
Homes rated E, F, and G often qualify for the most support because they need more significant improvements to reach modern energy standards.

During your free home assessment, a surveyor will check:

• Your current EPC band
• Heat loss areas
• The condition of your heating system
• Which improvements will raise your property to a healthier EPC rating

What upgrades can improve your EPC rating?

Common EPC-improving upgrades include:

• Loft insulation
• Cavity or internal wall insulation
• Air Source Heat Pumps
• Solar PV panels
• Smart heating controls
• First Time Central Heating
• More efficient boilers (condensing only)

These measures reduce heat loss, lower energy usage, and help the home stay warm for longer.

Benefits of improving your EPC rating

Upgrading your EPC rating can:

• Reduce your heating bills
• Make your home warmer and more comfortable
• Increase your property’s value
• Improve air quality
• Reduce your carbon footprint
• Help the home meet future energy regulations

EPC improvements are one of the easiest and most cost-effective ways to save money long-term — and under ECO4, many of these upgrades can be fully funded.

Find out what your EPC is