What to look for in your ESOS Lead Assessor

Selecting an ESOS Assessor can be a challenge, with over 900 Lead Assessors now available in the UK alone.

ESOS participants must have their energy and fleet assessments conducted by, or signed-off by, a registered ESOS Lead Assessor.

A company will want to select a Lead Assessor with the necessary skills and experience to deliver their business to compliance.

Moreover, beyond providing a competitive quote, the principle aims of ESOS are to deliver significant and meaningful financial savings; these derived from energy savings which lead to carbon dioxide (CO2) and greenhouse gas (CO2e) emissions reductions. These CO2 emissions have particular relevance following new legislation known as “Streamlined Energy and Carbon Reporting” (SECR); This is an annual requirement for most ESOS mandated companies and some smaller companies from 1st April 2019. Contact us for more information, to speak with a specialist or to establish if you need to comply.

In order to achieve an ESOS Phase 2 report that delivers savings beyond mere compliance, when selecting your ESOS Lead Assessor you should consider the things you would consider when appointing any other professional services:


  1. Can they provide evidence and testimonials of energy auditing experience in your sector?
  2. Are they familiar with the processes and operations in your industry, not simply assessing your buildings?
  3. Do they have the experience to competently assess your transport fleet?

Beyond their experience, you should also consider: 


Are they on a recognised register (https://www.gov.uk/guidance/energy-savings-opportunity-scheme-esos#approved-registers-of-esos-lead-assessors)?

(Due to the race to get companies compliant during ESOS phase 1, several registers set the bar for ESOS Lead Assessor with very low standards – typically (and still) requiring only 2 years of experience and just 2 days of training).

Are they Chartered or Certified Energy Managers? 

As with all professions, the Royal Charter remains the industry standard. Across the world, only the Energy Institute, London, award the title ‘Chartered Energy Manager’; with the UK Association of Energy Engineers (UKAEE) conferring Certified Energy Manager (CEM) status.

Are they Chartered Fleet Managers? 

Only the Chartered Institute of Logistics and Transport, award such a Charter. Look for the letters CMILT.

Do they have energy management qualifications? 

The highest level of energy management training offered by any UK register is the European Energy Manager – EurEM (which has since become) the Advanced Energy Manager (AEM) – both only conferred by the Energy Institute, London.

The UKAEE offer training to achieve their CEM qualification which, whilst less vigorous, is of a high standard.

Conversely, qualifications such as Non-Domestic Energy Certificates/Assessors, NDEA / EPC Assessors have no relevance in the ESOS sphere.

CLS Energy are a team of Chartered and Certified Associates that deliver on all-of the above in the UK and Europe. Please get in contact to discuss your specific requirements or e-mail alan.asbury@clsenergy.com

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