How to improve your EPC Rating

Domestic EPC Rating

Domestic EPC Rating

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

All EPCs must be issued by an accredited Energy Assessor.

This article describes what the Energy Assessor is searching at when they carry out an EPC inspection, and at what simple measures you can take to make sure your property gets the very best possible rating.

In an EPC survey the Surveyor / Energy Assessor will probably be searching 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 data about all these elements; this data will then be fed into a piece of computer software which will create the EPC. The methodology used by the software to produce the EPC is the Decreased Data Standard Assessment Process (RDSAP). RDSAP is really a simplified version of the much more rigorous Standard Assessment Process (SAP) which, together with the Simplified Building Energy Model (SBEM) is used for producing commercial and new develop EPC. The simplified RDSAP methodology was chosen for domestic EPC production simply because the complexity of the other two methodologies results in the surveys costing a lot more to produce, something which was regarded as to be acceptable for the commercial marketplace but not for domestic properties.

At, we have access to both RDSAP in addition to 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 data. This makes domestic EPC simpler and quicker to produce, decreasing the price for landlords / vendors and consequently helping to increase compliance. This is all well and good, but does come at a price, as the use of assumption in location of gathered data can result in some properties becoming given an arbitrary energy rating that doesn’t correctly reflect the buildings performance.

Nevertheless, Commercial properties are much more complex by nature. There may be different parts of the property becoming used for different purpose. Various parts of the same property might have different heating requirements. And so on. And an Energy Assessor needs to spend much more time examining the property in addition to discovering its history.

On leading of the EPC software making assumptions the Energy Assessor might need to make some assumptions themselves when carrying out an EPC survey. When this occurs they are obliged to usually assume the worst; for instance when a light fitting is found to be empty they will usually need to assume that when the bulb is replaced it will be with an incandescent bulb instead of a low energy one.

You will find several low price measures the owner of a property can take to make sure that their building gets the very best energy rating possible.


The very first and most important factor to do would be to make certain that the assessor can get access to all of the parts of the property they need to inspect in the EPC survey, as any assumptions they are forced to create are likely to result in a worse EPC rating. For example if it is not possible for the assessor to access the loft region, either simply 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 can’t open the cupboard to see the cylinder then it will be assumed it has no insulation.

Have documentation ready:

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

Insulate your water tank:

As part 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 additional one, or putting one on over the foam insulation will make a noticeable distinction to your EPC rating.

Remove portable heaters:

If whilst carrying out the EPC inspection the assessor finds any portable electric or propane heaters in the property then they will be entered as a secondary heating method. In most cases this will result inside your property obtaining a lower energy rating, as they are likely to be a less effective means of heating than your properties primary heat source. If you eliminate these heaters then only the primary heart source will probably be taken into consideration.

Change coal for wood:

When you have a fire location inside your property then this will be entered in the EPC as either a coal or a wood heater. The Energy Assessor will make an assumption about what you burn in the fire based on what they see at the time of the inspection. If there’s no visual evidence as to what fuel you use they will be forced to assume it is coal, as this gives a worse rating than utilizing wood. It is consequently advisable to eliminate your coal scuttle, and replace it with 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 consequently advisable to block off any unused flues. This may be as simple as stuffing some spare loft insulation up there.

Low Energy Bulbs:

When 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 is only a little one. For example, changing all of the bulbs in a four bedroom hose from incandescent would make about a 2% distinction to the properties EPC rating. Whilst this is only a little improvement, it is possible that it could make the distinction to your rating if you’re on the borderline between, for instance, an E or a D rating.

Clearly there are lots of much more costly measures you could take to enhance your EPC rating, such as replacing your boiler with a band A boiler, increasing your loft insulation and filling your cavity walls. Nevertheless if you follow the above guidance then you’ll have done every thing possible to cheaply and effortlessly enhance your EPC rating before the Energy Assessor visits

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