An Energy Performance Certificate or EPC as it’s also known as is a document that assesses the energy efficiency of a building, rating it from A (most efficient) to G (least efficient).

EPCs are drawn up by accredited assessors who inspect key features of a property, such as insulation, heating systems, windows, and lighting. Using government-approved software, they calculate how much energy the home uses and how efficiently it’s retained.

The certificate also includes recommendations for upgrades that could boost the rating and lower energy costs.

An EPC provides an overview of a building’s energy efficiency. It typically includes:

  1. Energy Efficiency Rating: A scale (usually from A to G) that shows how energy-efficient a building is. The higher the rating, the more energy-efficient the building.
  2. Environmental Impact: Information on the building’s carbon dioxide (CO2) emissions, indicating its impact on the environment.
  3. Recommendations: Suggestions on how to improve the building’s energy efficiency (e.g., upgrading insulation, installing energy-efficient appliances).

In some cases, improving an EPC rating can even increase property value, making it an essential factor in real estate decisions.

Why Are EPCs Required?

EPCs aren’t just helpful; they’re legally required in many countries, including the UK. Originally introduced as part of European energy efficiency regulations, they remain a key tool in the UK’s strategy to cut carbon emissions and reduce energy waste.

In England, Wales, and Northern Ireland, an EPC is required when:

  • Selling a property
  • Renting out a property
  • Constructing a new building

Scotland has slightly different rules, requiring EPCs to be displayed in rental properties.

EPCs help governments track national energy efficiency progress. By ensuring properties meet certain standards, they contribute to sustainability goals and help reduce the country’s overall energy consumption.

What’s Included in an EPC?

An EPC provides a detailed breakdown of a property’s energy efficiency, including:

  • Energy Efficiency Rating – A color-coded A to G scale, showing how energy-efficient the property is.
  • Estimated Energy Costs – A projection of how much it might cost to heat, light, and power the home.
  • Recommendations for Improvement – Suggested upgrades such as insulation, double glazing, or energy-efficient appliances.
  • Carbon Emissions – An estimate of how much CO2 the property emits annually.
  • Potential Savings – A comparison between the current rating and the potential rating if recommended improvements are made.

These details help property owners and tenants make informed choices about energy use and efficiency upgrades. 

For landlords, EPCs also ensure compliance with minimum energy standards for rental properties.

How Is an EPC Rating Determined?

A qualified EPC assessor visits the property to examine key elements that affect energy efficiency, including:

  • Insulation – Loft, cavity wall, and floor insulation significantly impact heat retention.
  • Heating systems – The type, age, and efficiency of boilers, radiators, and thermostats.
  • Windows and doors – The presence of double or triple glazing.
  • Lighting – The use of energy-efficient bulbs and fixtures.
  • Renewable energy sources – Solar panels or heat pumps can boost the rating.

The assessor inputs this data into government-approved software, which calculates the final rating. Homes with modern condensing boilers, smart heating controls, and well-sealed windows tend to score higher, while outdated systems, poor insulation, and inefficient lighting lower the score.

The assessment also considers secondary heating sources, ventilation, and even the materials used in construction to provide a comprehensive energy overview.

Why Do EPC Ratings Matter?

Aside from being a legal requirement, a good EPC rating can:

  • Increase property value – Buyers and tenants often prioritise energy-efficient homes.
  • Lower energy bills – More efficient properties cost less to heat and power.
  • Help landlords comply with regulations – In the UK, rental properties must have at least an E rating (with some exceptions) to be legally let.
  • Support environmental goals – Better-rated homes contribute to lower carbon emissions.
  • Improve comfort – Well-insulated homes with efficient heating are more comfortable year-round.

For homeowners looking to sell, a strong EPC rating can make the property stand out in a competitive market. Similarly, tenants are increasingly prioritising energy efficiency when choosing rental homes, making a good EPC a valuable asset.

Whether you’re a homeowner, landlord, or tenant, understanding your EPC can help you make informed decisions about energy efficiency, running costs, and future improvements. 

So, if your certificate is nearing expiration or you’ve never checked yours before, you can check your EPC here.