How to improve your EPC Rating

Domestic EPC Rating

Domestic EPC Rating

It is a legal requirement for all domestic properties within the UK to have an Energy Performance Certificate (EPC) in location before a property is sold or rented out.

All EPCs should be issued by an accredited Energy Assessor.

This article describes what the Energy Assessor is looking at when they carry out an EPC inspection, and at what easy measures you can take to ensure your property gets the best feasible rating.

In an EPC survey the Surveyor / Energy Assessor will be looking at 5 main elements as follows:

  • How the property is constructed
  • How the space is heated
  • How the water is heated
  • How the property is lighted
  • What ventilation systems are in place

The Energy Assessor will collect information about all these elements; this information will then be fed into a piece of computer software which will generate the EPC. The methodology utilized by the software to create the EPC is the Reduced Data Regular Assessment Procedure (RDSAP). RDSAP is a simplified version of the more rigorous Regular Assessment Procedure (SAP) which, along with the Simplified Creating Energy Model (SBEM) is utilized for producing commercial and new build EPC. The simplified RDSAP methodology was chosen for domestic EPC production because the complexity of the other two methodologies results within the surveys costing much more to create, something which was regarded as to be acceptable for the commercial market but not for domestic properties.

At, we have access to both RDSAP as well as SAP methodologies as we carry out both Domestic and Commercial EPC work.

The RDSAP procedure entails the software making a series of assumptions in location of gathered information. This makes domestic EPC simpler and quicker to create, decreasing the cost for landlords / vendors and therefore helping to increase compliance. This is all well and good, but does come at a cost, as the use of assumption in location of gathered information can result in some properties becoming given an arbitrary energy rating that doesn’t properly reflect the buildings performance.

However, Commercial properties are more complex by nature. There may be various parts of the property becoming utilized for various purpose. Various parts of the same property may have various heating requirements. And so on. And an Energy Assessor needs to spend more time examining the property as well as finding its history.

On leading of the EPC software making assumptions the Energy Assessor may need to make some assumptions themselves when carrying out an EPC survey. When this occurs they’re obliged to always assume the worst; for instance when a light fitting is found to be empty they will always need to assume that when the bulb is replaced it will be with an incandescent bulb rather than a low energy 1.

You will find several low cost measures the owner of a property can take to ensure that their building gets the best energy rating feasible.


The first and most important factor to do is to make sure that the assessor can get access to all of the parts of the property they need to inspect within the EPC survey, as any assumptions they’re forced to create are likely to result in a worse EPC rating. For example if it’s not feasible for the assessor to access the loft region, either because the hatch is locked or access via under eves storage cupboards is blocked by stuff, then the assessor will need to assume no insulation is present. The same applies for the hot water cylinder, if the Energy Assessor cannot open the cupboard to see the cylinder then it will be assumed it has no insulation.

Have documentation ready:

If your property, or any component of it has been converted because 1996 then the Energy Assessor will be able to enter the date of conversion as the construction date for that element within the EPC, but only in the event you can show them the building regulations sign off sheet, otherwise the construction date will be entered as the same as the main buildings original construction date, resulting in a worse EPC rating.

Insulate your water tank:

As component of the EPC inspection the Energy Assessor will take a look at how well insulated your hot water tank is. Most tanks have 25mm of foam insulation or a jacket. Hot water cylinder jackets are inexpensive to buy, and adding an extra 1, or putting 1 on over the foam insulation will make a noticeable difference to your EPC rating.

Remove portable heaters:

If whilst carrying out the EPC inspection the assessor finds any portable electric or propane heaters within the property then they will be entered as a secondary heating technique. In most instances this may result inside your property obtaining a lower energy rating, as they’re likely to be a less efficient means of heating than your properties primary heat source. In the event you remove these heaters then only the primary heart source will be taken into consideration.

Change coal for wood:

If you have a fire location inside your property then this may be entered within the EPC as either a coal or a wood heater. The Energy Assessor will make an assumption about what you burn within the fire based on what they see at the time of the inspection. If there is no visual evidence as to what fuel you use they will be forced to assume it’s coal, as this gives a worse rating than using wood. It is therefore advisable to remove your coal scuttle, and replace it having a wood basket.

Block up unused flues:

Any open flue will result in a lower EPC rating, as they will be letting the heat rise out of your property. It is therefore advisable to block off any unused flues. This may be as easy as stuffing some spare loft insulation up there.

Low Energy Bulbs:

If you have any light fittings with missing bulbs then fit them with low energy light bulbs. It is not recommended to go around replacing all of your incandescent bulbs with low energy units, but rather just to replace them as the old ones burn out. Whilst low energy bulbs do have an effect on the EPC rating, it’s only a small 1. For example, changing all of the bulbs in a four bedroom hose from incandescent would make about a 2% difference to the properties EPC rating. Whilst this is only a small improvement, it’s feasible that it could make the difference to your rating if you are on the borderline between, for instance, an E or a D rating.

Clearly there are many more expensive measures you could take to enhance your EPC rating, like replacing your boiler having a band A boiler, increasing your loft insulation and filling your cavity walls. However in the event you follow the above guidance then you will have carried out everything feasible to cheaply and effortlessly enhance your EPC rating before the Energy Assessor visits

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