Providers of Energy Performance Certificates in the South East

Specialists in Domestic and Commercial EPCs

UNDERSTANDING Domestic EPCs

Domestic EPCs

The national software for creating EPCs makes standardised assumptions about energy usage (e.g. The same temperatures, for the same periods of time, in the same type of room in the same type of property) which means that the calculated costs of heating, lighting and hot water may be significantly different to the actual bills paid by the occupier. 

These theoretical costs are displayed below the graphs on the front page of the EPC.  This permits the energy efficiency of one property to be easily compared with another property of a similar type.

Graphs similar to those above are created from the data gathered and entered into the National Computer by the energy assessor who visits the property.  Many factors are taken into account including geographical location, age, construction, building style, glazing, insulation, heating and lighting types, and method of generating and storing domestic hot water.  These determine the ‘Current’ ratings.

The energy efficiency rating of a 1930s bungalow will normally be lower than say a modern mid-terrace house which will have the inherent protection from the elements, as will a converted flat in a Victorian terrace, with high ceilings and sliding sash windows compared to a modern well insulated flat.
The cost of fuels is also taken into account and as a consequence a remote property which has to rely upon heating oil or LPG will have a significantly lower rating than a similar property with a heating system fuelled by mains gas.  When comparing EPCs it is worth checking the actual date of the EPCs since if fuel costs have changed significantly between the dates then the ratings will be skewed.

The average dwelling in England and Wales is calculated to have a rating of 46 (Band E).

The second half of the EPC gives recommendations to improve the rating and shows the potential savings per annum (against the theoretical costs on the front page) if the recommendations were to be carried out. 

These recommendations are split into three categories:

  • Lower Cost Measures
  • Higher Cost Measures
  • Further Measures

The ‘Potential’ arrows on the rating graphs are the improvement expected if all of the Lower and Higher cost measures are implemented. Further measures are not included since they may represent significant costs.

The wording of the EPC including any comment like "Poor", "Average" or "Good" is automatically generated by the national software so as to ensure uniformity