Frequently Asked Questions

What is an EPC?

An EPC is a document that shows the energy efficiency rating of a building. It uses a grading system from A (most efficient) to G (least efficient). It provides recommendations on how to improve energy efficiency.

When is an EPC required?

When selling a property.
When renting out a property.
When building a new property.
Before marketing a property for sale or rent, the estate agent must be satisfied that a valid EPC is in place.
An EPC must be given to the new buyer or tenant.

Do I need an EPC to sell or rent my home?

Yes. In the UK, it is a legal requirement to have a valid EPC when selling or renting a property. The EPC must be ordered before the property is marketed, and the rating must meet the minimum legal standard.Yes. In the UK, it is a legal requirement to have a valid EPC when selling or renting a property. The EPC must be ordered before the property is marketed, and the rating must meet the minimum legal standard.

How long does an EPC last?

An EPC is valid for 10 years. If you make energy-efficient upgrades, you’ll need to book a new EPC survey to reflect your improved rating.

How much does an EPC cost?

The cost of an EPC varies depending on the size and type of property. At i-EPC, we offer competitive rates for houses, flats, with fast, accurate EPC ratings provided by accredited assessors.

How can I improve my EPC rating?

You can improve your EPC rating by adding insulation, upgrading to double or triple glazing, installing energy-efficient lighting, and using renewable energy sources like solar panels. Our EPC survey will give you personalised recommendations for your property.

How the energy performance of a building is calculated?

The energy rating of a building is a complex calculation which is based on a combination of factors:

the type of building (i.e. flat, house or bungalow) and whether it is detached or not
the age of the building
the number of habitable rooms (excluding kitchens, bathroom hallways, stairs and landings)
extensions and their construction and rooms in the roof
the dimensions of the building and the number of floors
the amount and type of glazing (i.e. single or double glazing)
the material used to build the property (e.g. brick, stone, timber frame, etc.)
wall insulation
roof construction (e.g. flat, pitched) and insulation
the number of chimneys and open flues
the heating systems and the type of fuel used

The energy rating is adjusted for the floor area of a building so it is independent of size for a given type of building. The rating is calculated on the basis of standard occupancy to ensure that the results are consistent for similar building types and relate to the physical fabric of the building rather than the energy usage patterns of the individual occupant, which can vary appreciably between households.

The rating is independent of the number of people living in your household, how many domestic appliances you own (such as washing machines and refrigerators) and how efficient they are and how you choose to heat your home (i.e. individual temperature settings and how long it is heated during the day or night). This allows prospective buyers or tenants to compare the energy rating of buildings on a like for like basis.

What an energy assessment involves

For existing buildings, the energy assessor must undertake a physical survey of the building to gather the appropriate information. For new buildings, the energy assessor will have accurate plans, specifications and other relevant information and a site visit is not required.

During the visit the energy assessor will need to access all the rooms, the boiler and the loft (if there is safe access). The assessor may take photographs of items, such as heaters and meters, and may take photographs of any unusual features in the building. The energy assessor may also photograph any area that cannot be accessed or visually inspected (for example, a fully boarded loft).

A visual inspection may not be possible for all features (for example, cavity wall or under floor insulation) and without supporting information and evidence, such as receipts, the energy assessor will not be able to include that feature in the EPC.

If access to inspect parts of the building is not possible, (for example, safe access to the loft to determine if it has been insulated), an assumption will be made about those features based on the age of the building. Energy assessors are not required to take unnecessary risks when undertaking an energy assessment.

Collecting the information required for an EPC

The energy assessor will need know about how the home has been built. Finding supporting information before the energy assessor visits will ensure you get the most accurate energy efficiency rating for your building. If you have up to date information this process will be less time consuming. The energy assessor is responsible for ensuring the information used in the energy calculations is accurate and, even where detailed plans are available for existing buildings, must validate the information provided.

The assessor will need to know:

when the building was built (searches or deeds may provide evidence)
whether or not the building has been extended and when
if it has been double glazed, any certificates that may be available
whether the walls have been insulated and if so whether this is cavity, internal or external insulation
when boilers and hot water cylinders were installed and their make and model (any manuals may provide evidence)
the location of room thermostats and heating timers
the location of gas and electricity meters
the type of heating fuel you use and the types of heating you use for your rooms

Once the assessment is completed the data is fed into a government approved software programme. The software will produce the EPC and recommendations using the data collected.

How the EPC and recommendation report is produced

The government approved software programme uses data, together with standard performance tables, to assess the energy performance of the building and to produce the EPC and recommendations. The software also generates a 20 digit non-sequential reference number from the data.

The energy efficiency of buildings is assessed using a method known as Standard Assessment Procedure (SAP). SAP is used during the construction process to demonstrate that a new building meets energy efficiency targets. New buildings typically have a lot of information readily available for the calculation, such as detailed floor plans and specifications. Most new buildings complying with current Building Regulations will achieve a C or B rating. If new buildings are being specifically promoted as being environmentally friendly, you should expect them to be at the top end of the B band or possibly in the A band. When a building is constructed, the EPC must always be based on the full range of information required.

For existing buildings much of the information required to assess the energy performance is not readily available so a survey is needed to collect it. To minimise inconvenience for the homeowner, the method to assess the energy performance was adapted to include a set of assumptions about the building based on conventions and requirements at the time the building was constructed. This means that less information is required from the homeowner for the assessment than for a new build property. This adapted method is called Reduced data Standard Assessment Procedure (RdSAP).

Generally, for buildings being marketed for sale or rent RdSAP is the appropriate method of assessment. For certain types of building, however, the SAP method will give a more accurate rating. The types of property where the SAP method might give a more accurate rating include buildings constructed to current Building Regulations standards, or those that have been refurbished with advanced energy efficiency measures installed. Using the SAP method for an existing building will require more detailed and extensive information. When the SAP method is used for older buildings, the energy assessor will need to ensure that any recommendations proposed are appropriate for installation in the building.

The process for registering EPCs

Only an approved energy assessor can lodge data on to the domestic EPC register (‘the register’) through their accreditation scheme. An EPC is only valid if it has been generated from data lodged on the register and each set of data has been allocated a report reference number. The register is the only official place for storing EPC data.

Once the data has been successfully lodged on the register the energy assessor must provide the seller or landlord with a copy of the EPC. Alternatively, if the seller or landlord agrees, the assessor may provide the report reference number for the data on the register, so they can print off their own copy of the EPC.

Once the EPC data is registered it cannot be altered. Data is kept on the register for 20 years, so one building may have several EPCs for the whole building or individual building units. Only the most recent EPC for each distinct building or building unit is valid.

Checking the authenticity of an energy assessor

An EPC may only be produced by an accredited energy assessor. Energy assessors must be a member of an approved accreditation scheme.

To check that an energy assessor is a member of an accreditation scheme, a search facility is available on the register website. If a person does not have access to the internet they can ask the energy assessor for the name of the accreditation scheme of which they are a member and for their membership number. All EPC assessors should be able to show their accredition ID.

This information will help the person who has commissioned the EPC to confirm with the accreditation scheme that the energy assessor is accredited and fit and proper to practice as an energy assessor and to produce the EPC for the type of building being assessed.