A comparison between an EPC and a DEC

When it comes to assessing the energy efficiency of a building, EPCs and DECs are the major two ways used to measure this. While you may have heard of these terms before, you might not know exactly what they mean and how they differ. This is certainly something worth knowing more about if you plan to engage in energy assessor training and gain accreditation in this field.

Display Energy Certificates explained

A DEC is basically a certificate which measures how much energy a building has used over the preceding year. It gives an accurate record of how any building performs in reality when it comes to energy efficiency. Looking at a building's DEC can help to pinpoint areas where energy efficiency can be improved as it shows concrete evidence of where any issues may lie.

What is an EPC?

This is short for Energy Performance Certificate and is a theoretical prediction of how energy efficient any building could be. This takes into account what the building is used for amongst other things and is based on the building being used in a standardised way. Ratings are given in letter format with A being the most efficient. Comparing the rating given to different buildings is a simple way for people to look at which are more energy efficient in theory.

How do they differ?

Although they look similar, it really comes down to what is being measured. A DEC rates how efficient a building is in operation and are required for buildings with a total useful floor area over 250m2 that are occupied in whole or part by the public authorities and frequently visited by the public. In contrast, an EPC is a theoretical measure of how efficient it could be. A DEC will come to its conclusion by using hard evidence like utility bills and the type of systems installed while an EPC will come to its rating based on things like building design. This means that it is not feasible to expect the two to say the same in most cases.

Choose Elmhurst Energy for domestic energy assessor training

If you want to help drive energy efficiency in buildings, why not train to be an energy assessor? Here at Elmhurst Energy, we are sure you will love our energy assessor course choices and the full accreditation we can offer too. Call today for more details.

Article published 23th October 2019

If you need help get in touch!

Fill out our short contact form below if you would like to find out more about the information displayed on this page

© Elmhurst Energy Systems Ltd 2022. All rights reserved.
Elmhurst Energy Systems Limited is registered in England, Company Number: 02805846