Commercial EPC

Energy Performance Certificates – How are they calculated ? How to Prepare for an EPC Inspection

Energy Performance Certificate

How are Energy Performance Certificates (EPC) Calculated and How Do I Prepare For My EPC Inspection

Here we are going to provide you with a rough guide as to what is going to happen on the day of your home visit by the Energy Assessor on the property visit. to complete your Energy Performance Certificate We will show you what elements of the property that need to be assessed. While providing tips on how to make the property inspection as accurate and detailed as possible. And as quick and hassle free for yourself.

Energy Performance Certificate home inspections are a non-invasive process, meaning that all of the assessing is done visually. We will not be knocking holes in walls to look for cavity wall or insulation or lifting floorboards to look for loft insulation. This means that if we cannot see a particular energy saving element of the property. Or if you are unable to provide original documentation of any home energy saving elements, then we are unable to add this into the report.

The importance of Documentation for an accurate Energy Performance Certificate.


Energy Performance Certificate


Relevant documentation might come in the form of building notices from building control or building works drawings etc. If you don’t have the relevant documentation, it is possible for you to organize someone, to expose your property’s energy saving measures. This will help to improve the overall accuracy of the Energy Performance Certificate (EPC).

Before I travel to any Energy Performance Certificate (EPC) appointment, I always carry out an online check of the property which I am to survey. These days with such technology available to us I am able to ascertain, a lot of information from an online search. Looking at the property on Google street view or any other searches results provided allows me to roughly work out how long each Energy Performance Certificate (EPC) will last so I can give myself plenty of time, to accurately record all the relevant data.

When I arrive at a property my first priority is to make a detailed map of the house, including taking accurate dimensions. The property may be measured internally or externally depending on access or possible weather-related reasons. The height of each floor of the house will also be recorded and this will always be recorded inside the property. It’s also important to map out each of the rooms in the floor plan to accurately count the habitable rooms in the property. Access to all rooms in the property must be required so if any doors are locked or blocked if you could arrange to have the keys left in place and any obstructions cleared.


Energy Performance Certificate

One of the most important tools that an energy assessor and I know myself the most important tool that I carry is my mobile phone. I mainly use my phone as a camera, but it also has other uses to an energy assessor. Being able to capture an image of a home improvement measure is essential as if we are unable to take a clear photograph, or unless I am provided with a relevant and original document, the element will be discarded from the survey report. You will often see your energy assessor taking photographs in and around your property of everything, from the thickness of the walls, to the depth of the floor insulation in between the joists in the roof space. These photographs that we take the form an important part of our auditing process as they provide most of the evidence that is sent to the accreditation schemes that govern and control energy assessors across the UK. We are required by law to safely and securely retain the photographs and any physical documentation for a time of 10 years after the initial issuing of the Energy Performance Certficate (EPC) At no time will we share the photographs with anyone and they will not be saved with the property details on them.

After completing the property measurements and taking the required external photographs, the next element to workout is the age band in which the property lies. The possible age bands that are possibilities to be entered into the Energy Performance Certificate (EPC) report are.

  • a) Before 1919

  • b) 1919-1929

  • c) 1930-1949

  • d) 1950-1973

  • e) 1974-1977

  • f) 1978-1985

  • g)1986-1991

  • h)1992-1999

  • I) 2000 – 2006

  • j)2007 – 2913

  • k 2014 onwards

Most homeowners are aware of the age of the property’s or have the deeds to the property’s, if not it is possible to ascertain the age of a property through period details, brick bonds, and style. It might also be worthwhile if you are not aware to ask a friendly neighbor, maybe one that has lived there a long time as they might know more information.

The heating system in a property can make a big difference with the rating of an Energy Performance Certificate. The age of the system and the type e.g Gas, Oil or Electric Heating, could mean substantial differences in the energy efficiency of similar properties. In order to aid the energy assessor visiting your property to correctly record your heating system, you should make access to any heating elements visible.

This essentially means clearing coats from cloakrooms which cover heating time clocks/ programmers. Also the removal of any clothes or towels that are often found located in the Hot Water Cylinder cupboard. It is also helpful if you have the original documentation of any heating system containing the make and model number if it is not already clearly displayed on the system. If you do not have the original documentation or if the sticker containing the make and model of the number has been removed or damaged, then a result will be used based on the average energy efficiency of systems of the same type and age.

If your heating system is located within your garage or any other outbuildings or is contained within a padlocked boiler house, then it is important to either remove the padlock prior to the visit or be present with the key.

Also recorded within the heating system section of the Energy Performance Certificate (EPC), are a property’s heating controls. Heating controls we use to control the temperature around our home or in parts of our homes at certain times. They include e.g.

  • TV’s Thermostatic Radiator Valves

  • Programmers (Digital/Manual)

  • Time clocks

  • Time and Temperature Controls (Zonal)

  • Room thermostats

Energy Performance Certificate

It is widely known the advantages that modern glazing has made the energy efficiency level of properties across the UK. Double glazing and now the ever more commonly seen Tripple glazing, has decreased the levels of heat lost from the property’s through poorly insulated draughty windows, drastically helping save energy and coining the phrase “pays for itself”. In property’s that are classified as having much more than typically sized windows compared to a standard dwelling of that size e.g an apartment with a large glass wall or sliding doors. Then you may see the energy assessor physically measuring the windows. The gap in-between the panes of glass is also measured. To help the energy assessor look for information regarding the manufacturer and age of the Windows, it is advisable to leave one unlocked to allow access the to the inside of the frame the most common place to find information on the product.

Moving from room to room within the property, there are various different items recorded. These Include

  • The type of lighting that is used in the room. e.g. how many lighting fixtures are in the room and which type of bulb is in the fixtures. The number of low energy bulbs and non-low energy bulbs are recorded as a percentage and placed into the Energy Performance Certificate (EPC) calculation software.

  • What is heating the room? Is there a fireplace in the room? And is this an open fireplace capable of burning solid fuels or has it been blocked up removing potential drafts.

  • Is there a radiator in this room and is it controlled by a TRV (Thermostatic Radiator Valve)

These would be some of the more common items that we need to check for, but property’s come in all shapes, sizes, and configurations, which is why it is important to take the time and carry out a thorough investigation.

The walls, floors and roof structure are essential details when it comes to many energy performance certificates, as they are often are the main elements of the property that nowadays contain the most widely used energy saving implements in the form of insulation.

The construction of property with cavity walls was widely implemented in Northern Ireland throughout the 1940’s. For the past few decades, it has become common practice the fill these cavity’s to increase the heat retention and suppress cold entering the building. The detection of cavity wall insulation can be particularly hard to establish if for example the wall has been rendered after the drill work and cavity wall pumping has taken place. If the cavity wall insulation work has been carried out by qualified tradesmen then a guarantee should have been supplied, and this will act as written documentation. Also building control notices which clearly state the date, may also be used for evidence as all work is guaranteed to be carried out to building control specifications based at the time when the work was carried out.

It is also essential for energy assessors to record the wall thicknesses at different points of a dwelling. This may mean opening some windows to allow for the accurate measurement of the openings.

Laying loft insulation is one of the cheapest, easiest and often the most accessible option for people wishing to carry out their own energy saving home improvements. Being able to accurately record insulation in a roof space is vitally important whether the insulation is laid in the joists in the voids or in the roof rafters. Where an attic has been floored over the insulation and none of the insulation is visible, then it is unable to be entered into the Energy Performance Certificate (EPC). Also if the roof space is full of personal items and the floor is obstructed, or if the roof hatch is inaccessible e.g. painted shut or locked then any insulation within the roof space will not be included within the Energy Performance Certificate (EPC).

Floor Insulation is the most difficult insulation to detect as it often means exploratory works need to be completed, which is definitely not the most convenient for someone wishing to rent or sell their property. Where there is no visual evidence or documentary evidence of floor insulation the, addition of floor insulation will be based on the building control regulations based on the time that the property was first constructed. You may also see your energy assessor walking around the ground floor of your property banging their heels. This is simply a test to determine the construction of the floors whether solid concrete floors or suspended timber flooring.

Renewable Energy Systems are becoming widely more popular as they become more efficient and affordable across the world. Often subsidized with grants by local councils or government backed schemes. As an energy assessor, it’s important for me to keep up to date and to be aware of different types of renewable energy, and energy conservation systems.

Where renewable energy systems are present in a property then various pieces of information need to be gathered. There are two main types of new technologies which can currently be entered into an Energy Performance Certificate (EPC) report.

The first of these new technologies are Photovoltaic Panels. These are essentially giant versions of the panels that power solar powered calculators. While still quite rare in existing dwelling throughout Northern Ireland, they are becoming increasingly more popular as the technological improvements making them a much more desirable product. When Photovoltaic panels are present on the roof of a property, it’s important for us to record as accurately as possible, the orientation, elevation and any possible shading of the panels. This is another case when I use my phone to use the gyroscope as a compass to determine the orientation of the panel.

The second of the new technologies able to be entered into and Energy Performance Certificate (EPC) report is a Wind Turbine. While much more common in rural areas, especially throughout Northern Ireland. And not something that I have come upon just yet, but calculations are needed, more than likely by the owner. Often the owners of the most uncommon and high-end efficient systems are very proud of their systems and are normally more than a will to share and give advice and talk me through the workings of the system.

Energy Performance Certificate

As I said before all properties are unique. And the software that we use to enter a property’s details allows us to use techniques to allow for the widely varied differences of properties.

As newer and more energy efficient technologies enter the markets, and with more efficient building techniques and materials being created constantly. The business of energy efficiency with a domestic property is every changing. Keeping on top and being aware of new technologies, techniques, and following the every changing and improving methods of efficiently assessing properties is the reason were the No.1 choice.