Energy Performance Certificates

Energy Performance Certificates provide a standardised energy, or ‘asset’, rating for a building, based on the inherent energy performance of the fabric and systems within that building. The EPC and accompanying ‘recommendations report’ suggest measures that could be implemented to improve the energy performance of the building.

Recent research has shown this process can significantly underestimate the thermal performance of traditionally constructed buildings resulting in a poorer rating. Furthermore, EPC recommendations take a fabric first approach instead of assessing the building's performance as a whole, and do not consider the way the building is operated or used. As such, ratings may lead to inappropriate recommendations which could harm the character or risk deterioration of such buildings. Historic England has published case studies to raise awareness of the issues (see below).

Legal requirements

An EPC is legally required when a building is built, sold or rented and is valid for 10 years. Further advice is set out on the government’s web page Buying or selling your home.

There are some private rented sector (PRS) exemptions. The government’s Guidance on PRS exemptions and Exemptions Register evidence requirements (March 2019) explains the exemptions.  

Listed buildings and buildings in conservation areas may obtain an exemption if ‘in so far as compliance with certain minimum energy performance requirements would unacceptably alter their character or appearance’. Our web page about Energy Performance Certificates and the Minimum Energy Efficiency Standards explores what this means in practice.

Improving EPCs for historic and traditionally constructed buildings: case studies

In 2020 the government consulted on increasing the Minimum Energy Efficiency Standards (MEES) for privately rented domestic properties for new tenancies from 2025 and all tenancies from 2028. This was followed up with an action plan (November 2021) to improve the quality, methodology and outcomes of the EPC process. Historic England, in conjunction with the National Trust, Country Land and Business Association, the Central Association for Agricultural Valuers, the Landmark Trust, and other stakeholders, carried out case studies to provide the Department for Business, Energy and Industrial Strategy with evidence about applying EPCs to retrofitting historic/traditional constructed buildings. The case studies focus on the EPC assessment procedure, fuel types, overall costs, and impact on traditional construction.

The case studies show the need to:

• Incorporate an understanding of traditional building performance with appropriate data and models in the EPC software
• Provide a system for planning works that will achieve compliance ahead of any future methodology updates
• Provide clear guidance to Domestic Energy Assessors and landlords on acceptable evidence of hidden measures such as insulation
• Update Standard Assessment Procedure (SAP) and the reduced assessment (RdSAP) methodology to take into account carbon emissions of heating systems
• Ensure all databases (for example heating systems) are kept up to date with current models available to ensure accurate energy efficiency can be reflected in the EPC
• Review the impact of fuel cost changes on EPC assessments
• Improve the recommendation section on the EPC to include a much wider range of measures, more accurate costs and more realistic estimated outcomes

Learn more

Our Technical Tuesday webinars look at:

• Conservation Retrofit: Energy Performance Certificates in the Private Rental Sector
• Energy Assessment: Theory versus Reality, a discussion on how historic buildings really operate, and the importance of not neglecting the building occupants in the assessment equation.  Freya Wise from the Open University joins the Historic England team to discuss her research findings.

For the best webinar experience, please use Google Chrome browser or download Adobe Connect.