Domestic EPCs are energy surveys that determine the efficiency of a property. The survey provides a numerical rating between 0 and 100, where 100 is the most efficient and 0 the least. The numerical ratings also fall into bands A-G, for example a D rated property has a numerical rating of between 55 and 68.

The UK has some of the most diverse properties seen around the world, creating a huge range of EPC ratings. For example, pre-1900 rural detached houses tend to have a drastically lower rating than 90’s mid terrace properties. The many Georgian and Victorian properties that make up a huge proportion of the housing stock in London are not very efficient at all.

The introduction of building regulations in the late 60’s led to a sharp increase in energy efficiency of properties and as stricter regulations continue to be released even now (the last building regulations update was in 2013), efficiency continues to improve.

At London EPC, it is this massive diversity in building stock is what makes our job so interesting, we never quite know what to expect when we go from property to property!

A domestic EPC will look at the type and amount of external wall, floor, ceiling, as well as the heating systems, heating controls and glazing. One thing the EPC doesn’t do is consider the energy usage of the current occupier and how they use the property. All the energy savings that you find in the lodged EPC report are based on ‘typical’ occupancy, so if the current occupiers are high or low energy users the savings produced by installing particular energy saving measures are going to vary considerably.

Why were domestic EPCs introduced?

Domestic EPCs were introduced in August 2007 as part of the Home Information Pack, for properties with four or more bedrooms, however this was soon extended to smaller properties. When the Home Information Pack was removed in 2010, the Energy Performance Certificate remained in place, and has been a requirement for certain scenarios ever since. The EPC displays both the energy performance of the property as well as the carbon emissions rating.

The EPC is designed to give the potential buyer, tenant or even occupier more information on the efficiency of the property. Along with the score, the EPC also provides a few energy saving recommendations, which the owner can then chose to follow and therefore improve the EPC rating. A lower rating should mean that the property would be more expensive to run. However, there are exceptions to the rule, but it is still a useful guideline.

When would I need an EPC for my home?

Across the UK, if you are looking to sell or rent the domestic property, or if it has just been constructed then you would require an EPC to be undertaken as a legal requirement. The ‘economic agent’ then has the most up-to-date information on the property and can base his plans accordingly.

EPCs are valid for 10 years; however if for whatever reason a new one is lodged on the same property, it will overwrite the existing EPC held on the central register (known as EPCregister). We recommend obtaining a new EPC if the property ever goes through large-scale changes, such as extensions or adding lots of insulation. Even something as simple as replacing your lighting with LED lights can boost the EPC rating of the property if you are looking for quick wins!

EPC and the Renewable Heat Incentive

One area where an EPC is crucial is for calculating the renewable heat incentive or RHI as it is more commonly known. The amount paid via the RHI is based on figures that come directly from the bottom of the EPC – so for renewable heat generating systems – such as Air Source Heat Pumps or Biomass boilers, the EPC is absolutely critical – you can learn more about the Renewable heat incentive by clicking here.

Can I get away without having an EPC?

So if you have lived in the same property since before the EPC was a requirement, and have not sold or rented it since, then naturally your property may not have one.

Even if you have moved into a property since the Home Information Pack came into force in 2007, there might be circumstances where the property doesn’t need an EPC.

A domestic EPC is not required in the following circumstances.

  • A mixed-use property that is part of a business (e.g. farm, shop or petrol station)
  • Properties that have been deemed unsafe and pose a health and safety risk.
  • Properties to be demolished provided all documentation exists.
  • Listed buildings
  • Detached buildings with a footprint under 50m2
  • Residential buildings being used fewer than 4 months per year

How is the EPC produced?

A qualified domestic energy assessor will come to your property and carry out an EPC. The surveyor examines all external walls, levels of insulation, heating systems and heating controls, as well as other aspect of the property. However, while undertaking the assessment the assessor must not, and cannot, alter the property. For example, he cannot take up boarding to check loft insulation, take apart the boiler panel to see the model number or indeed lodge anything that he cannot see even if the customer tells him.

The only case in which something can be taken into account yet cannot be seen, is where documentation is provided as evidence. Therefore, when you book an assessment ensure that you have proof of any improvements that have been made, such as floor insulation, otherwise you might be disappointed by your EPC rating when you get it back from the assessor.

Domestic EPC authenticity

When a Domestic EPC is correctly lodged by a certified assessor, it will produce a unique number known as an RNN number, which is located on the top right hand side of the EPC certificate.

The certificate can be searched for independently by any prospective buyer or occupier on the domestic registry website ( as long as they have this RRN number.

If assessors send across an EPC without this information then the certificate is not lodged and you will be liable if the matter is investigated by building control.