EPC calculator

EPC assessors carry out the process of granting an EPC in England, Wales, and Northern Ireland, and by government-registered Domestic Energy Assessors in Scotland. The process involves surveying the property, after which the assessor will produce your Energy Performance Certificate. The energy report will include:

• Estimated energy costs for the property 
• A current energy efficiency rating from A to G, with A being the highest level of energy efficiency
• A potential EPC rating if the property is improved in key areas through energy efficiency improvements

Remember that existing dwellings will require a RdSAP EPC (Reduced data Standard Assessment Procedure), and a new dwelling will require a full Standard Assessment Procedure. Be sure to keep all documents that relate to the installation or upgrade of relevant energy efficiency projects for the home, as the process only accounts for measures that can be seen or proven.

For landlords, it is legally required to have a current EPC rated E or higher for any rental properties or to take in a new tenant. Your property also must meet minimum energy efficiency standards (MEES) for domestic lettings.

As a property buyer, this energy report is a valuable document that can help you forecast your energy bills, improve your energy rating, and plan improvements to reduce energy bills through energy-efficient measures. As green living trends continue to gain traction with potential buyers and renters, and those who want their money to go further, a high energy rating is a useful way to attract renters to your rental properties, show their potential savings on energy bills, and possibly help increase the value of the property when the time comes to sell.

Your property will be assigned Standard Assessment Procedure (SAP) points by the domestic energy assessor for each element of the assessment process, grading it for energy efficiency against a standardised energy-efficient rating system. 

When grading the home, the EPC assessor will look at many aspects of the property. These results shouldn’t be examined without context when considering an investment. For example, an old home that may be a very attractive rental or investment property will almost always have a lower rating than a new build. 

Typically, the assessor will look at the following in addition to the age of the building:

• Total floor space – Larger homes with higher volume rooms usually require more lighting and heating per square foot than smaller homes.
• Lighting – The percentage of energy-efficient lighting (LED) in the property.
• Windows – Single-glazed or poorly sealed windows will receive a lower rating than modern, sealed windows.
• Hot water heating – Heating systems that are fully insulated and modernised will receive a higher rating than old or non-insulated systems.
• Airtightness – The better the home is sealed against the elements, the more energy-efficient it will be to heat or cool. Weather tightness will include examining external doors and windows, attics and basement areas, pipe entry points, etc.

The final score will place your property within a band, grading it from A (most efficient) to G (least efficient). In the UK, the average home meets a D rating. It’s important to note that to rent out a buy to let property, the lowest EPC rating band your property can fall into is E.

EPC rating A

This is for properties that reach 92-100 SAP points. These homes have the highest energy efficiency and usually have exceptional insulation, modern energy-rated heating systems, passive home design elements, and high-efficiency green technology like solar panels, heat pumps, and smart energy-saving upgrades.

EPC rating B

These properties score between 81-91 SAP points, which is still very high. They may be older but recently upgraded properties where the owners have consciously invested in energy-efficient products and technologies or homes built recently.

EPC rating C

‘C’ rated properties score between 69-80 SAP points, a respectable rating above the UK average. These homes may be older and lacking in certain areas but have some key upgrades that promote energy efficiency, including insulation, weatherproofing, or solar panels. These homes are a good opportunity for investors to upgrade their EPC rating and the property’s value.

EPC rating D - least efficient

This is the average rating for residential buildings in the UK, scoring between 55-68 SAP points. These homes often have a lot of opportunities for improving the EPC rating and typically have elements such as old boiler/heating systems, unused/no secondary heating systems, poor air tightness, old/inefficient insulation, and single glazing. In these homes, simple and affordable upgrades can make a significant difference to the home’s comfort, renter appeal, and value.

One of the most valuable aspects of this energy report is that it shows estimated energy costs at the current level of energy efficiency and the potential savings if certain upgrades and energy-efficient measures are applied. This is divided into 3 key categories: 

• Lighting
• Heating
• Hot water 

The report projects savings over the next three years in line with the potential energy-efficient rating the domestic energy assessor believes the property can reasonably achieve.

This is especially useful for buy to let property investors, as it can help you better understand the returns you will get on energy efficiency upgrades. While these savings may be passed on to the renter in most cases, the lower lighting, heating, and hot water costs can make the property that much more appealing to renters, allowing you to increase your rental yield from rental properties, improve attractiveness to potential buyers, and maximise profit when selling the property.

EPCs are generally very affordable, but they will vary from provider to provider. You can expect to pay around £75-£120, especially if the assessment is through a real estate agent. Third-party providers can also assist you and vary the price according to the property size.

There are many ways to improve your property’s EPC rating, and many of them are affordable too. These projects don’t often impact the aesthetics of your property but will make it more comfortable and affordable to live in – and it improves the home’s value too. Here are some of the most effective ways to improve your EPC rating.

Wall insulation

Internal wall insulation in all the main cavities of a home will help improve your EPC rating. This can be a rapid and affordable process, carrying potential savings of around £160 per year. External wall insulation will also help make the home easier to warm, can improve the exterior look of the property, and protect the walls and foundation from moisture damage. Typically, this is best suited to homes built post-1920s and can improve your rating by 5-10 points.

Loft insulation

Because heat rises, a property can lose as much as 33% of its warmth through an uninsulated ceiling space. For maximising efficiency for your EPC rating, it’s recommended that you install loft insulation that is at least 270mm thick with a 100mm layer between the joists and a 170mm perpendicular top layer. This can improve your rating by 10-15 points.

Double glazing

Installing double-glazing will add several points to your EPC rating and is highly recommended if you have old single-glazing windows. However, it will not make too much of a difference if you have older double-glazed windows.

Boiler replacement

Upgrading to a high-efficiency condensing boiler is another good way to add up to 20 points to the property’s EPC rating. This will depend on how old and inefficient the current boiler is, keeping in mind that boilers should be replaced every 10-15 years. If the home has a hot water cylinder, you should insulate this tank to gain a few points affordably and save on water heating costs.

More efficient secondary heating

Secondary heating systems like fireplaces, space heaters, and fixed wall heaters are also considered in the EPC assessment. Upgrading to a more energy-efficient system (for example, a wood-burning stove rather than an open fireplace) can help gain additional points.

No. Since 2013, listed residential buildings have been exempt from EPCs. However, you must ensure that it meets minimum requirements for energy efficiency if you intend to sell or rent the property. 

The easiest way to make sure that your residential buildings are meeting these standards is through an EPC assessment. However, you can disregard any suggestions that can harm the authenticity of the building. You may also need permission to install certain upgrades, including renewable energy sources, a new high-efficiency boiler, or weatherproofing, and some upgrades like double-glazing or insulation may be denied.

EPC stands for Energy Performance Certificate.

As part of the EPC, you’ll also receive an Environmental Impact Rating (EIR) that determines the carbon footprint (carbon dioxide emissions or carbon emissions) of residential buildings. This is also banded from A to G, and, as with the EPC rating, the higher the EIR, the lower the carbon emissions and the lower the impact the property has on the environment. 

In addition to getting a current EIR, you will also get a potential EIR to show how you can upgrade your property to reduce carbon dioxide emissions if you want to do so.