How is an EPC Calculated?

An Overview of the EPC Process

The Energy Rating on an EPC (Energy Performance Certificate) is calculated using information about various factors of your property.

In a nutshell we are looking at how the property is built, so factors such as the type of wall and insulation and then how you use energy in the property, considering factors like your heating systems and lighting.

The final rating given considers how good the property is at keeping in and reducing the energy you use and then how you use that energy to heat and light the property in the first place.

One of our Assessors will visit the property to collect information such as the fabric of the property and the type of heating systems, with visits normally taking around 30 minutes.

All of the factors are then input to a calculation using the Government's Reduced Data Sap methodology, or RDSap. The result of the calculation, based on the u value efficiency of each factor, is a number rating. This number then indicates the Category, from A - G, within which that property falls, its EPC Rating.

The technical requirements and legislation relating to the scheme are overseen by the Ministry of Housing, Communities and Local Government.

All Domestic Energy Assessors have to go through training and exams and be registered by an approved EPC Certification Body in order to lodge EPC's ( Energy Performance Certificates)