Energy Performance of Buildings Certificates: notes and definitions

Information on how statistics on energy performance of buildings are compiled.

Applies to England and Wales

This guidance is to be read in conjunction with the experimental official statistics series on Energy Performance of Buildings Certificates, which includes the latest statistical releases and sets of tables.

About the Energy Performance of Buildings Certificates

The Department for Levelling Up, Housing and Communities (DLUHC) is responsible for the Energy Performance of Buildings Regulations (England and Wales) 2012 (the regulations), which require that:

  • properties (homes and commercial) must have an Energy Performance Certificate (EPC) when constructed, sold or let
  • larger buildings over 250 square meters occupied by a public authority where the building is frequently visited by the public must display an energy certificate; in England and Wales this is a Display Energy Certificate (DEC)
  • all air-conditioning systems over 12kW must be regularly inspected by an energy assessor and given an Air-Conditioning Inspections Report (ACIR)

For an EPC, DEC or ACIR to be valid, it must be lodged by an accredited energy assessor on the Energy Performance of Buildings Register (EPB Register).

The EPB Register for England, Wales and Northern Ireland is operated by DLUHC, although this statistical series covers England and Wales only. The Northern Ireland register operates on DLUHC’s register platform under the control of the Northern Ireland Executive. Scotland holds its own register.

As of March 2021, the England and Wales register contained data related to over 24.5 million certificates. The volume of data held on the EPB Register increases daily. The statistics produced reflect the data lodged for valid certificates at time of publication.

Regulatory and administrative history and context

Data from EPCs and DECs are collected under the regulations and subsequent amendments. This was first introduced in 2007 and is designed to improve energy efficiency and to tackle climate change by reducing the amount of carbon produced by buildings.

Several regulatory and administrative amendments have been made since the implementation of the 2007 regulations, which have altered the content, format and accessibility of data lodged on to the EPB Register. The relevant changes are listed below in chronological order.

Technical guidance notes

For full details on how the requirements of the regulations are applied to domestic dwellings, non-dwellings and public buildings, users should consult the Energy Performance Certificates guidance collection.

For the purposes of reading the statistics, the following explanations are provided to support users’ interpretation.

Technical guidance notes

Data quality

This is an experimental official statistics series drawn from data held on the EPB Register for England and Wales.

Experimental official statistics are by definition still subject to evaluation and testing, and therefore may not meet the same rigorous quality standards as official statistics more generally. We are publishing these figures, because we believe them to be of immediate value and we welcome interested parties to become involved in their development.

Energy Assessor Accreditation Schemes originally had the choice of lodging the underlying data used to produce domestic EPCs, in addition to the actual PDF document itself. After September 2008, lodging the data became a mandatory requirement. Due to the technical difficulty involved in formatting PDFs into searchable data, the statistics do not include data lodged as a PDF document only.

In May 2009, additional validation checks were introduced into the register lodgement process to identify prescribed data quality issues. Before this period, statistics for domestic buildings may include anomalies to CO2 emission rates. In addition, statistics for domestic and non-domestic buildings and for DECs may include anomalies which affect total floor area figures.

On 1 April 2012, the first set of Scheme Operating Requirements came into effect for Domestic Energy Assessors, which set new rules for the operation of Accreditation Schemes. One new requirement was to introduce quality assurance audit of EPCs. The result was a demonstrable improvement in the quality of the lodged data from mid-2012 onwards. Users are asked to consider this when interpreting figures prior to that period.

Statistics from October to December 2014 onwards includes EPCs for properties defined as park homes.

The Department for Levelling Up, Housing and Communities cannot alter data which has been lodged on the EPB Register.

Historic series and archive publications

Between 2010 and 2013, official statistics on the average energy efficiency of new homes in England and Wales were released quarterly as a sub-section of the Code for Sustainable Homes statistics series.

These statistics were drawn from EPC certificates for new domestic buildings, held on the Energy Performance of Buildings Register. Please refer to this series for earlier tables and reports.


A consolidated glossary of all the terms used in the EPB reports.


Published 30 April 2014
Last updated 25 May 2021 + show all updates
  1. Updated guidance.

  2. First published.