This website uses cookies to help us improve your user experience and create reports. The cookies collect information in an anonymous form.
Please visit our privacy policy page to learn more about the cookies used on this website and how to change current settings if you do not agree. By continuing to use this website, you consent to the use of cookies.        

The Energy Savings Opportunity Scheme (ESOS)

Improving business performance through energy efficiency

The EI runs one of the biggest registers of qualified ESOS lead assessors – experienced professionals to help your business get the most out of its energy spend, providing advice you can trust.

You may also be interested in

What is ESOS?

ESOS is the UK’s response to Article 8 of the European Commission’s Energy Efficiency Directive. It aims to cut carbon emissions by requiring the thousands of large businesses that operate in the UK to measure their energy consumption and identify measures that could be implemented to achieve energy savings.

You will need to comply with ESOS if your organisation operates in the UK and:

- employs 250 or more people,

- or has an annual turnover in excess of 50 million euro (£38,937,777), and an annual balance sheet total in excess of 43 million euro (£33,486,489)

Under ESOS, all companies required to comply must undertake an energy audit conducted or overseen by an approved ESOS Lead Assessor once every four years, unless the organisation is fully covered by ISO 50001.

Audits will include an estimate of total energy consumption covering buildings, industrial processes, and transport, and identify energy saving opportunities. The audit must be signed off by a board-level director before being submitted to the national scheme administrator.

The first deadline was 5 December 2015, and the next deadline is 5 December 2019. By that date you will need to have completed the following steps

  1. Measured the organisation’s total energy consumption;
  2. Conducted audits to identify cost-effective energy efficiency opportunities; and
  3. Reported compliance to the national scheme administrator – the Environment Agency in England, SEPA in Scotland, NIEA in Northern Ireland and NRW in Wales.

Find an ESOS Lead Assessor

The EI has two listings of energy efficiency professionals who are approved to act as ESOS Lead Assessors, the Register of Professional Energy Consultants (RPEC), and our listing of Chartered Energy Managers approved as ESOS Lead Assessors. You can use these to find an experienced energy efficiency profession who can work through the ESOS process with you and help you identify real energy efficiency savings.

All professionals on our listings required to hold Chartered status and follow a strict Code of Conduct (link), so you can be sure that your organisation will get the best energy advice and that the services you receive are up-to-date, timely and professional.

Go to RPEC and Consultants

The list of In House Lead Assessors lists those Chartered Energy Managers who are approved to act as ESOS Lead Assessors but perform that role within their own organisation. Some have moved into consultancy roles and may be available to be contracted to perform ESOS assessment on a consultancy basis.

In-house Chartered Energy Managers

The following Chartered Energy Managers are approved to act as ESOS Lead Assessors and offer their services to businesses

Chartered Energy Managers available to third parties

Become ESOS Lead Assessor

Interested in joining our registers?

There are two routes to becoming an ESOS Lead Assessor with the EI –

  • By qualifying as a Chartered Energy Manager through the EI and demonstrating that you meet the PAS standards
  • By joining RPEC, the Register of Professional Energy Consultants, our expert register for those who specialise in energy efficiency advice

Click the tabs below to find out more about each route.

The ESOS Toolkit

The EI’s ESOS toolkit is designed for those undertaking ESOS audits. This toolkit can be used by anyone working towards ESOS compliance, whether you are an ESOS Lead Assessor or are working within a company preparing to appoint an assessor.

The toolkit includes:

  • Tool A: Overview and introduction - a guide to ESOS and the toolkit
  • Tool B: Total Energy Consumption tool - collate energy data for a Company or Group in either units of energy cost, energy   consumption or distance, and produce a view of the total energy profile.
  • Tool C: ESOS Audit Template - outlines the scope, content and output of a best practice ESOS Audit.
  • Tool D: Life Cycle Cost Analysis tool - collate data from scenarios and determine the life cycle cost analysis of business as usual verses an investment in new equipment. Compare over a defined period of between 1 and 20 years.
  • Tool E: ESOS Commercial considerations - advice for consultants entering into an agreement with a client to conduct ESOS work. (May also be useful from a client point of view when hiring a consultant.)

For more information, watch our webinar: A guide to using the ESOS Toolkit


  • Members of the EI’s Lead Assessor registers (RPEC or Chartered Energy Manager): £99 + VAT - to order please contact us at e:
  • Other EI member: £149 + VAT
  • Non-member: £299 + VAT

10% discount for purchase of five or more toolkits in the same transaction.

More about ESOS

  • ESOS Briefing: A more detailed guide to the ESOS legislation and its requirements. Download the Briefing
  • ESOS FAQs: The most common questions about ESOS compliance and regulations answered. Download the FAQs
  • ESOS Presentation: slides from our presentation - ‘Preparing for ESOS Phase 2 – Applying the lessons learnt in Phase One’, presented at the 2018 Edie Energy Management Forum. Download the presentation slides