Buildings are required to be assessed and subject to energy performance certificates. This legislation applies whenever a building is marketed, constructed, sold or rented or to existing buildings for public use. There are also specific requirements for the inspection of air conditioning systems.

This legislation implements the Energy Performance of Buildings Directive (EPBD - 2010/31/EU), which aims to increase the energy efficiency of buildings and reduce their carbon emissions. It introduces two types of building energy certificates: Energy Performance Certificates (EPCs) and Display Energy Certificates (DECs).

Energy Performance Certificates (EPCs) 

EPCs: When are they required and what do they include?

EPCs classify a building with an energy efficiency rating (A-G) and must be produced (by accredited assessors) for all buildings whenever a building is marketed, sold or rented, but not when they are gong to be demolished.

An EPC must be provided on construction of a building, or where it is modified to provide less or more parts for separate use and this has involved modifications to fixed services for heating, hot water, air conditioning or mechanical ventilation. A 2016 amendment transferred the duty to provide an EPC under these circumstances to these regulations from the Building Regulations 2010. 

The EPC will be accompanied by recommendations for cost-effective actions to improve the rating. They must include the address, useful floor area and date issued.

An EPC must be displayed in commercial premises larger than 500m² that are frequently visited by the public (where an EPC has previously been issued on the sale, rent of construction of that building).

EPCs: Exempt Buildings

EPCs are not required to be prepared for exempt buildings, including:

• industrial sites, workshops, religious buildings, protected buildings and non-residential agricultural buildings with low energy demand;
• temporary buildings with a time of use of two years or less; and
• stand-alone buildings with a total useful floor area of less than 50m

Display Energy Certificates (DECs)

DECs are specific EPCs, produced by accredited assessors, for buildings occupied by a public authority or an institution providing a public service with a total useful area greater than 250m2. 

They show the actual energy usage of a building, the Operational Rating, and are based on the energy consumption of the building as recorded by gas, electricity and other meters. The DEC should be clearly displayed at all times in a prominent place clearly visible to the public. A DEC will be accompanied by an Advisory Report that lists cost effective measures to improve the energy rating of the building. DECs are valid for one year for buildings over 1000m2, or 10 years otherwise. The accompanying Advisory Report is valid for 7 years.

Air Conditioning System Inspections

The legislation requires the inspection of air conditioning systems with an effective rated output of more than 12kW (whether in dwellings or non-dwellings) at least 5 years following the installation of the units comprising it, and at 5-year intervals subsequently. The principal guidance on these inspections is provided in CIBSE's TM44 document. 

A “system” is defined as the sum of individual cooling units under the control of one building operator/owner. The inspection will include an assessment of efficiency, a review of their sizing and advice on improvements or replacements and alternative solutions.

Generally, a 12kW cooling capacity air conditioning system is used in the following types of premises:

• general office spaces up to approximately 200 square metres;
• offices with high levels of IT and electrical equipment up to 100 square metres;
• retail spaces with average levels of display lighting up to 250 square metres;
• retail spaces with high levels of display lighting and illuminated cabinets up to 150 square metres.

An office building of 2,000 square metres is likely to need air conditioning with a 250kW output.

A 2020 amendment kept the 12kW threshold requiring inspections but requires that inspections consider the capabilities of the air-conditioning system for combined air-conditioning and ventilation to optimise performance. 

Amendments

• Regulation EU/244/2012 establishes a comparative methodology framework for calculating cost-optimal implementation measures to meet the minimum energy efficiency requirements for new buildings and refurbishment of existing buildings.
• A 2013 amendment requires any Green Deal information to be included in EPCs.
• The Energy Performance of Buildings (England and Wales) (Amendment) Regulations 2015  revise the fees for accessing data on the EPC register.
• A 2022 amendment sets fees for lodging domestic and non-domestic EPC data on registers, which is required before each EPC may be issued.
• A 2024 amendment enables further anonymised data to be published from energy assessments online. Owners, landlords, occupiers and authorised third parties may access further assessment information, including that was not lodged on the public register.