How is an EPC Produced
EPC's
How is an EPC produced?
An EPC can only be produced by either a Domestic Energy Assessor (DEA) or by a Home Inspector (HI), who must be approved by either a Government approved Accreditation or Certification scheme.
The DEA will visit the property to assess the energy related features. These are then entered into a computer programme which is a calculation model, developed by the Government, known as RDSAP (Reduced Standard Assessment Procedure).
This is a cost based rating system using pre determined assumptions and therefore rates the property on its "built in" energy efficiency rather than the actual energy consumed.
A site visit will be arranged to suit the client and then I will travel to the property. The inspection should take approximately 1 hour depending on the size, is non-invasive and will cause the minimum of inconvenience.
The only significant factors to be aware of is that I will require access to the loft space, if present, gas and/or electric meters and boiler. Photographs will also need to be taken. An internal and external inspection of the property is carried out for the purpose of the EPC, based on:
- Property type
- Age and type of construction
- Property dimensions
- Room and water heating systems
- Insulation levels including loft, where applicable
- Windows and glazing type
- Make and model of boiler
- Types of lighting
- Look for any 'green' devices, e.g. solar panels
These will then be passed through the RDSAP calculation and an EPC will be produced.
The EPC displays the Energy Efficiency Rating and Environmental Impact Rating
The performance of a property is rated in terms of the energy used per square metre of floor area; the energy efficiency based on fuel costs; and the environmental impact based on CO2 emissions.
The numbered arrows show the current rating based on the existing energy performance of the property and the potential rating if the suggested improvements are implemented.
The EPC also gives a summary of energy performance related features in the form of a table which is broken down into the most crucial energy related elements, such as:
- Wall construction type
- Roof construction type
- Floor construction type
- Windows and glazing
- Main heating system present
- Main heating controls
- Secondary heating
- Water heating
- Low energy lighting
The table then shows how each of the different elements are performing in terms of their current energy efficiency and environmental impact. The descriptions provided are on the data that has been collected specific to the property's thermal and heating elements, these are:
- Very poor
- Poor
- Average
- Good
- Very good
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 not usually 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 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 'poor' rating because of the cost associated with electricity compared to the cost of gas.
The environmental impact may also rate as 'poor' 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 certificate also provides some recommendations of measures that can improve the energy efficiency and therefore the SAP rating of the property.
The recommendations are divided into:
- Lower cost measures - below £500 installation costs
- Higher cost measures - above £500 installation costs
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 shows 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.
Further Information
Further information on EPCs and the full EPBD legislation can be found at: