The energy performance certificate (EPC): an efficient tool for housing

There are a number of things to look out for before buying or renting properties. One of which is the energy performance  certificate, known as the EPC. It contains valuable information for the owner as well as the buyer/tenant. The energy performance certificate is an important piece of information as they show how energy efficient a property is. With the current increase in energy prices and climate change, the EPC seems more essential than ever...

What does the energy performance certificate of a property mean?

The EPC is a rating scheme that summarizes the energy efficiency of a building (heating, hot water, etc.) and the greenhouse gas emissions it produces. The energy performance certificate is a preventive measure for the future buyer or tenant. It provides effective ways to improve your home energy and also gives information about the thermal comfort of the building. Following the assessment, the owner can anticipate renovations to improve the EPC and the value of the property.  A low EPC can be a deal breaker for future buyers or tenants of the building.

The EPC also has a role to play in the energy transition in view of the current climate situation. The UK has been at the center of global action to tackle climate change and has led the way by decarbonizing its economy. This document is in line with the Energy-Climate law initiated in 2019 by the UK to reduce its greenhouse gas emissions to net zero by 2050. 

What type of building does the EPC cover?

The EPC applies to all types of public or private buildings. This document is used for both single-family homes and flats in buildings as soon as they are put up for sale or rent.

Why is it important to carry out an energy performance assessment in your home?

By law, all domestic and commercial buildings in the UK available for sale or rent must have an EPC. To complete an EPC, an accredited energy assessor will have to visit your property to conduct a visual survey. A Domestic Energy Assessor (DEA) is an accredited position, and it is approved by the Ministry for Housing, Communities and Local Government (MHCLG) now called the Department for levelling up, housing and communities (DLUHV).

Find an energy assessor in England, Wales and Northern Ireland.

Find an accredited assessor in Scotland.

Is the energy performance assessment mandatory?

In 2003, The Energy performance of buildings directive(EPBD) was introduced by the European Union. The UK followed suit with the introduction of the EPC in August 2007 for domestic buildings and in October 2008 for commercial buildings. It has remained an important aspect of selling or renting a building till today. There are exemptions for certain property types and all exemptions must be registered on the national register. Each registered exemption is valid for five years. Not having an EPC could lead to an enforcement action and the issuing of a penalty charge notice.

Marketing agents also have a legal responsibility to have EPCs in place for the buildings they advertise.

What is the validity period of the energy performance assessment?

In 2010, the validity period for the energy performance certificate was extended from 3years to 10 years. Under the current UK guidelines, landlords are required to update the EPC at least once every 10 years and they are available for public view on the Landmark database of the government.

How do you read an energy performance certificate?

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An EPC is divided into several parts:

The first part of the certificate shows: the date of validity, certificate number, a description of the property and the total internal floor area, based on measurements taken by the energy assessor at the time of their visit.

The other parts of the EPC are:

  1. Current and potential energy costs
  2. Energy efficiency rating
  3. Performance
  4. Recommendations


1. Current and potential energy costs

This section examines the estimated energy costs of the house, currently divided into lighting, heating and hot water.

It is important to note that this is an estimate of costs and not based on energy used by individual households. It does not include energy used for running appliances like computers, cookers, fridge and TVs.

This section is helpful when you’re trying to understand how much a property could cost to run if you were to buy or rent it.

2. Energy efficiency rating

This indicates the energy consumption of the property and it looks like the energy labels on home appliances. It is measured using the unit kWh/m2/year. Some EPCs include the environmental performance of the property. This shows how the building performs in terms of carbon dioxide emissions.

The energy label is divided into 7 classes ranging from A, which is the most efficient and cheapest to run, to G, the worst. The best classes are green while the worst classes are in red. It shows the potential rating if the suggested improvements were to be made.

The 7 energy classes of the EPC

All energy labels have these classes:

Class A

This is the least energy-intensive class.  It means that the property's consumption is low because it does not exceed 50 kWh/m2 annually. There are few properties with an A class.

Class B

This is used for properties with a consumption between 50 and 90 kWh/m2.

Class C

This class corresponds to a property with a consumption between 91 and 150 kWh/m2. This means that the energy consumption is relatively good.

Class D

Many properties have this energy class, which is rather energy intensive. It represents a consumption between 151 and 230 kWh/m2. This is the average EPC rating in the UK.

Class E

Properties with an energy consumption of between 231 and 330 kWh/m2 are included.

Class F

This is used for properties with a consumption of between 331 and 450 kWh/m2.

Class G

The G class represents the most energy-intensive properties because their consumption exceeds 450 kWh/m2. A building with this class is considered a heat sink.

The UK adopted the energy label regulation before it's departure from the EU and therefore the energy label was introduced from 1 March 2021, same as in the participating EU member states and 1 October 2021 for lighting products.

3. Performance

The next part of the certificate gives a breakdown of each element of the property, including walls, roof, floor, windows, main heating, main heating controls, secondary heating, hot water and lighting.

After each of these elements you will find a description and a ranking. This is sometimes given from one to five stars, five being the best. It can also range from very bad to very good.

This part of the EPC helps you understand how effective the construction of the property is, as well as the heating, hot water system and lighting.

4. Recommendations

This important part of the EPC outlines a list of recommended measures, including the associated costs and typical savings you could achieve. It shows how each measure can improve the energy efficiency of the property and the rating.

The recommended measures are outlined in order of importance and the improvement figures are based on making the changes in that order. The number of recommendations may vary.

The Domestic Minimum Energy Efficiency Standard (MEES) Regulations

The Minimum Energy Efficiency Standards (MEES) was launched in April 2018. This requires all rented or sold properties in England and Wales to have a minimum EPC rating of ‘E’ or above.

In December 2020, the government announced yet another change to the Minimum Energy Efficiency Standards. They proposed that all rental properties will need an EPC rating of ‘C’ or above by 2025.

The regulation changes hope to make homes more energy-efficient and reduce carbon emissions as part of the government's plan to be net-zero by 2050.

Recommendations for the new 2025 EPC regulations?

Achieving an EPC rating of ‘C’ will be harder than an ‘E’, particularly for older properties. The government recommends a “fabric first” approach, covering wall, loft and floor insulation. Smart meter installation is recommended.

Energy performance investment is currently capped at £3,500 for landlords, but because the higher EPC rating will require a greater investment, the cap will be raised to £10,000. The government estimates that on average the improvement needed to reach an EPC rating of “C” will cost landlords around £4,700. They are encouraged to apply for the ''Green Homes Grant'', which will fund at least two-thirds of the cost of renovations to upgrade the energy performance of their properties.

An overhaul of the EPC since the summer of 2021

The EPC has undergone several changes since its inception.

  • Firstly, it is no longer only informative but also enforceable. What does this mean in practice? If there is a difference between two assessments, i.e., if the buyer or tenant of the property has a new assessment drawn up and it does not correspond with the initial EPC presented by the owner, they can request compensation or take legal action.
  • The method of calculating the EPC has been revised to better track down thermal flaws.
  • The theoretical amount of the bills must appear on the EPC as well as certain information such as recommendations for work, an indicator of the building's comfort in summer.

How is the energy performance assessment calculated?

As a reminder, the official energy performance assessment can only be carried out by a certified energy assessor. It is possible to calculate the EPC yourself to estimate its value, but in no case will this estimate be valid for selling or renting a property.

The calculation must take into account several criteria such as the year of construction of the property, its surface area and if it is attached to other buildings.

The EPC Calculation method

The calculation of the energy rating on the EPC is derived from the Standard Assessment Procedure (SAP). Existing properties are assessed using Reduced Data SAP (RdSAP), a simplified version of the SAP methodology that requires fewer data inputs. SAP and RdSAP are derived from the UK Building Research Establishment's Domestic Energy Model (BREDEM), which was originally developed in the 1980s and also underlies the National home energy rating scheme (NHRM). EPCs are produced by domestic energy assessors, they are registered under an approved certification scheme.

What are the solutions for homes with poor energy performance assessments?

Undertake renovation measures to improve your EPC

One of the best ways to improve the energy performance of your home is to carry out some renovation. Below are some areas you can choose to improve on:

  • Loft : which represents a central point in the conservation of heat in a building. This is the first phase of your renovation.  
  • Windows : They are largely responsible for heat loss. It is therefore necessary to improve their insulation, particularly with a double or triple glazing.
  • Floors : It is important to consider the thermal and compression resistance.
  • Internal walls : this is a practical solution when it is not possible to modify the external facade of the building. It is a more economical solution.
  • External walls : insulating walls from the exterior is an excellent technique that often provides higher thermal comfort than insulating from the interior.

The Netatmo Smart Thermostat

Thermal comfort certainly requires renovation, but it also requires appropriate heating equipment and solutions. According to YouGov Smart thermostats are part of a smart revolution that currently sees 23% of people in the UK own one or more smart home devices. Smart thermostat can save you as much as £154 per year. The Netatmo Intelligent Thermostat  sets a heating program according to your usage, which means you don't have to heat your home unnecessarily when it's empty or when rooms are unoccupied.

The Netatmo Intelligent Thermostat  allows you to keep control of your heating regardless of the time of day or where you are. You can turn down your heating at any time when you feel the room is too hot. In addition, the Auto-Adapt function allows you to adapt the temperature of your home to the best possible conditions, taking into account your insulation as well as the outside temperature.