Well, you have probably seen the rating graphs given to fridges, washing machines etc. rating the appliance from A to G on how energy efficient it is, so the following Energy Performance Certificate (EPC) graph might look familiar.

The EPC works in the same way, grading the property from A to G on the amount of carbon dioxide it produces using a standard occupancy formula. This means although you might not use your property in the same way as estimated, given the appliances, insulation, heating controls etc. that are present in the property, it will produce a certain amount of carbon dioxide under the same standard occupancy conditions.

This formula has been created by taking a house in a cold windy area in the North of the country, and a warm sunny area of say Cornwall, and averaging the two to figures to find a neutral base for the calculation.

Then it has taken an average number of people using the house, for instance 2 adults and 2.4 children! Plus the average number of hours per day that we would heat our living area and bedroom area (known in SAP terms as Zone 1 and Zone 2) during weekdays and then weekends. Zone 1 and Zone 2 are estimated at being kept at 21 and 18 degrees respectively.

So, if you work all day through the week and go out during the days at weekends, chances are your usage will be lower than someone who stays at home all week and the weekend with young children who need to be kept warm! But there has to be a system and something to compare every house to.

With all this in mind, the average rating across the country is 46 (out of 100) which is a band E. If you have a listed building or at least a very old house, you can expect the rating to be in band F or G more often than not. Likewise, if you have a house built since 1985 you should be able to expect a band D or higher. But unless your house is totally solar and wind powered etc. Don’t expect a band A!

Here is an example of a property rating:

If you have any questions about this, or an energy rating you have received, of if you would like help understanding the graphs on houses you are looking to buy please feel free to call me or send me an This e-mail address is being protected from spambots. You need JavaScript enabled to view it , I will be happy to help.