The Energy Performance Certificate (EPC) is a European Union (EU) initiative as part of the drive to improve energy efficiency across the EU member countries. An EPC provides two key pieces of information:

You will be provided with an EPC certificate when you move into your home. The EPC provides a rating of a property’s energy efficiency and displays this as a graph, similar to those found on kitchen appliances.

Ratings come on a scale of A-G, with A being the best rating. This means that home owners and occupiers can compare the energy efficiency of different properties in a similar way to comparing the energy performance of fridges or freezers.

The EPC also includes a Recommendation Report which lists the potential improvements that can be made to a property in order to:

The EPC is split into the following four sections:

An EPC can only be produced by a Domestic Energy Assessor (DEA) or a Home Inspector (HI) who is a member of an approved Government Accreditation scheme. The energy assessor will visit the property to determine the energy related features. These are then entered into a computer program which has a calculation model developed by the government and is known as Reduced Data Standard Assessment Procedure (RDSAP).

RDSAP is a cost-based rating system which uses pre-determined assumptions. It does not look at the appliances, but rather the performance of the building itself in areas such as heating and lighting. In other words, it provides an energy efficiency rating for the property itself rather than an occupancy rating.

When collecting the RDSAP data the energy assessor will need to determine the following:

This information will be entered into the calculation software and an EPC will be produced.

Since 2009, as part of the Energy Performance of Buildings Directive (EPBD) issued by the EU, all buildings in the UK that are constructed, sold or offered for rent need an EPC.

The estimated energy shows the estimated energy use, CO2 emissions and fuel costs of the dwelling.

The figures in the table are based on standardised assumptions about occupancy, heating patterns and geographical location. This means that the figures displayed will be different to the actual fuel cost.

The reasons for this are:

The summary of energy performance related features section of the EPC shows the most crucial energy related elements of the property in the form of a table. The table is broken down into the different elements of the property such as:

The table then shows how each of the different elements of the property are performing in terms of their current energy efficiency and environmental means least efficient and 5 stars means most efficient.

In some cases, due to the RDSAP calculation methodology, some of the elements have to be assumed. Floors are a typical example of this as it is usually not possible for the energy assessor to identify whether any additional floor insulation is present. This is because the survey is non invasive and the assessor cannot use a drill to lift floorboards or pull back carpeting.

Some of the descriptions could lead to concern for the homeowner and it is important to understand the reasoning behind these. For example, the energy efficiency of the hot water system may be given a single star rating because of the cost associated with electricity compared to the cost of gas. The environmental impact may also rate as a single star due to the carbon emissions associated with electricity generation. This does not mean that the system is of poor quality, poorly manufactured or poorly installed.

The recommendations section lists measures that can improve the energy efficiency and therefore the SAP rating of the property. The recommendations are separated into:

The measures are assessed cumulatively in a predetermined order and are only included if they make a measurable change to the energy efficiency of the building.

The recommendations section also displays typical savings per year and shows the energy efficiency and environmental impact ratings as a result of these improvements.

Finally, there is a description of each recommendation and explains how it can be used to improve the energy efficiency of the home. It also gives advice on how the recommendation can be applied/ installed.

For example, if a recommendation was given to replace an existing boiler with a more energy efficient Band A condensing boiler, the accompanying text would read as follows:

“Band A condensing boiler
A condensing boiler is capable of much higher efficiencies than other types of boiler, meaning it will burn less fuel to heat this property. This improvement is most appropriate when the existing central heating boiler needs repair or replacement, but there may be exceptional circumstances making this impractical. Condensing boilers need a drain for the condensate which limits their location; remember this when considering remodelling the room containing the existing boiler even if the latter is to be retained for the time being (for example a kitchen makeover).

Building Regulations apply to this work, so your local authority building control department should be informed, unless the installer is registered with a competent persons scheme, and can therefore self-certify the work for Building Regulation compliance. Ask a qualified heating engineer to explain the options.