What is an EPC or energy performance certificate
What is an EPC
An EPC is an acronym and stands for Energy Performance Certificate. It grades a property from A to G with regards to how efficient it is from an energy point of view. Currently there are 5 forms of an EPC and are split into 2 groups, residential and commercial.
Residential EPC’s
A residential property is loosely classified as a dwelling where a person or family can live, eat and sleep. It must have it’s own bathroom and kitchen facilities. As defined by the Land Registry and Gov.org
There are 2 types of residential EPC’s, the first is for when a new home before it is built. It is called an ‘On Construction EPC’. It is started before the first brick is laid and using only the schematic drawings and lists of materials. This method results in a SAP (standard assessment procedure) score.
It is then handed in along with the blue prints to the planning office. Plans cannot be approved until this has been completed. The assessor must verify the new property once is built and that the building and materials used were as per plan.
The second type is the most common type and is known as an RDSAP EPC (reduced data standard assessment procedure). These are used and calculated on properties that are already built.
A valid EPC is required by law for any property that is being marketed for sale or rent. It then needs to be displayed with the property details so potential buyers are aware of the property efficiency.
The only exceptions to this rule is if a property is marketed with the intention of it being demolished. Or if it is a certain classification listed building.
If a new property erected in the place of a demolished property an OCEPC will be required.
How The House Photographer calculates a residential EPC’s
When we calculate an EPC score it is compared to a notional building that has been built to the relevant building regulations at the time of its construction. It also takes into account improvements that have been made such as a new boiler or double glazing.
The key factors are as follows:
Building:
- the size of the property
- The year the property was built
- How the property is insulated
- What materials were used in the construction of the property
- Are the walls solid or do they have a cavity
- Property type; terraced, semi detached, detached, bungalow or flat
- Year any extensions were built and size
- Year any loft conversions were completed and size
- The percentage of low energy lights
Heating:
- how the property is heated
- How the heat is controlled in the property
- What type of heat emitters
Water:
- how the water is heated and stored
- What insulation the water storage vessel has
- How the water heating process is managed
A residential EPC can be calculated and a result given in most cases on the same day and normally within an hour, but obviously the size and complexity of the property will have an effect on the time required.
By law, a residential EPC is valid for 10 years so long as there have not been any changes to the heating system, insulation or size of the property.
An auditor must audit a percentage of jobs completed by an assessor. Assessor can only remain licensed if they have passed a series of periodic audits, based on quantity submitted. The assessor must also be insured and have a clean CRB certificate. Consequently is deemed to be a fit and proper person.
How The House Photographer calculates commercial EPC’s
Commercial EPC
Commercial EPC’s are for properties that are not built or designed for use as a residential home. They can include offices, hotels, shops, sporting facilities, studios and restaurants.
There are 3 classifications of a commercial EPC, levels 3,4 & 5.
Commercial EPC classification
Level 3 & 4 commercial EPC’s are the same except a level 4 has a more powerful and intricate air conditioning and heating system. A level 3 cannot have an air conditioning system that is greater than 12kW over 12kW systems will require a level 4 EPC.
A level 5 commercial EPC has the same characteristics as either a level 3 or 4 but has a domed roof. As a domed roof requires a specific type of calculation methodology only level 5 assessors can complete a level 5 commercial EPC.
Properties that are exempt from an EPC are listed buildings, places of worship and temporary buildings that will be only in existence for 2 years or less.
How are commercial EPC’s calculated?
Commercial EPC’s are calculated the same way as a residential EPC except in greater detail. Each room is broken down into various walls, floors and ceiling and the materials used.
Lighting, heating and ventilation also plays a major part in the calculations as does hot water heating and storage.
A commercial EPC can take up to a few days to complete due to the mass of calculations and back end work required prior to submission. As this is a complex subject we have kept this brief. Therefore a full and more detailed explanation can be supplied if required.