General Explanation of an EPC

EPCs, their importance and methodology - A General Explanation

Importance
Energy costs are escalating. Also it is widely accepted that Global Warming is happening and that greenhouse gases (e.g. CO2) are the main cause. The consequences of Global Warming are likely to be severe.

More than 50% of the UK's energy consumption arises from the way in which our buildings are lit, heated and used. Even comparatively minor changes in the energy performance of and the way we use each building would have a significant effect in reducing energy consumption and cost, and carbon emissions.

Given the UK Government's support of the Kyoto Protocol and its challenging targets for the reduction of CO2 emissions, reducing energy consumption attributable to buildings is a key policy objective.

The energy efficiency of housing stock/offices/industrial buildings could be vastly improved thereby reducing the UK's carbon footprint, mitigating climate change, strengthening energy security and saving money.

Energy Performance Certificates [EPCs] - Typical Efficiency Report Chart

The European Performance of Buildings Directive (EPBD) became European law on 4th January 2003 and stipulates that all EU states produce Energy Performance Certificates (EPCs) for all buildings including 'non-dwellings' (i.e. commercial buildings) that are marketed for sale or rent.

Energy Performance Certificates or EPCs - Typical Efficiency Report Graph

General methodology for domestic property EPCs
Once an EPC has been commissioned (either through a solicitor, an Estate Agent or direct with WDEA), an appointment will be made and a questionnaire completed, either over the telephone or written. The owner will be informed that clear access to the external perimeter of the building will be required, along with access to all rooms, the boiler, the hot water cylinder and loft space (if appropriate).

Energy Performance Certificates or EPCs - Typical Domestic House

The following documentation, if appropriate, should be made available if possible:

During the actual inspection the following will be undertaken:

The inspection is non-invasive. Keys can be collected from an agent or neighbour if necessary.

The collected data is entered into 'Reduced data Standard Assessment Procedure' (RdSAP) software. RdSAP is the Government approved standardised assessment procedure for energy assessments of existing dwellings. RdSAP is an industry agreed standard set of data items and a standard way of inferring the missing data.

Energy Performance Certificates or EPCs - Typical Home Awaiting Assessment

The calculated Energy Performance Certificate will rate how energy efficient a dwelling is on a scale from A to G (displayed as a coloured bar chart), provide a brief summary of the dwellings energy performance related features and recommendations for improvement. It also shows the dwellings Environmental Impact Rating, which is the amount of CO2 emitted.

The most energy efficient houses are in bands A and B, these will also have the lowest fuel bills per square metre of building and have the lowest impact on the environment. The average property in the UK falls into band D.

Methodology for commercial properties
The procedure for assessing commercial properties is similar to that described above for domestic properties, but much more detailed. The building is divided into separate zones based on activity, heating and ventilation systems, built in lighting and natural lighting and are assessed individually.

For commercial EPCs the pre-site survey questionnaire will be written and quite detailed and will include Health and Safety questions. An accurate floor plan of the entire building will be required, if one does not exist, then one will have to be drawn...

The EPC will calculate the building's Asset Rating, which is valid for 10 years. The Asset Rating is the building's intrinsic or 'built-in' energy efficiency standard – a theoretical value for how much energy/CO2 the building will consume/emit.

The EPC assessment method must comply with the National Calculation Methodology (NCM) as defined by 'Communities and Local Government' (CLG). This will usually utilise the Simplified building Energy Model (SBEM) software.

Contact the government (CLG) helpline on 0845 3652468 for authoritative advice and information on the EPBD (Energy Performance of Buildings Directive).

Energy Performance Certificates - Qualified Home Energy Assessors - EPCs Directors: Vaughan Jones, BSc & Clive Topper, BSc, PhD
Telephone: 01305 755615        Email:
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