Become a CIBSE Certification ESOS Lead Assessor

CIBSE Certification's schemes are for competent personnel who provide robust, impartial knowledge and guidance in the design and operation of energy efficient buildings, and management systems.

All schemes conform to the requirements of  ISO 17024:2012 and registrants must comply with competency requirements, our code of conduct, maintain appropriate insurance and meet our CPD requirements.

Join the CIBSE Certification register of industry respected professionals as an ESOS Lead Assessor.

What is ESOS? 

The Energy Savings Opportunity Scheme (ESOS) is a mandatory energy assessment and energy saving identification scheme for large undertakings (and their corporate groups). The scheme is applicable throughout the UK 

What is an ESOS Lead Assessor? 

In 2015 CIBSE Certification were approved to operate an ESOS Lead Assessor register in support of the ESOS Regulations. ESOS reports identifying the total energy use and energy savings opportunities for large organisations must be signed off by a registered ESOS Lead Assessor.  You need to be an LCC to become an ESOS Lead Assessor. 

The ESOS regulations require that ESOS Lead Assessors be sourced from approved existing schemes run by professional bodies, such as the CIBSE Certification Low Carbon Consultants register. Therefore CIBSE Certification ESOS Lead Assessor applicants are required to be registered as a CIBSE Certification Low Carbon Consultant.

The ESOS Lead Assessor certification scheme is open to anyone that can meet the entry requirements of competence, a minimum of two years of professional energy assessment and energy audit experience relevant to PAS 51215.

ESOS Registration Process

Stage 1. Register as a CIBSE Certification Low Carbon Consultant (LCC) if not yet registered

Choose which LCC strand you wish to join and pass the relevant LCC assessment.  There are no formal entry requirements, but it is advised that candidates familiarise themselves with the level of knowledge and experience (at least two years) expected beforehand and take appropriate training if required.

Visit CIBSE Training for more details and a list of upcoming LCC course dates.

Once you have passed the LCC exam, complete the LCC application process

Stage 2. Register as a CIBSE Certification ESOS Lead Assessor

Successfully complete an ESOS Lead Assessor training course and exam.  Visit for more details and a list of upcoming training dates.

1. Once you have passed the exam, download the ESOS Lead Assessor application pack
2. Complete the application form ensuring you and your referee have signed the form
3. Submit a copy of your employer's Professional Indemnity Insurance (PII) document. We cannot specify the limit of indemnity but we do recommend a minimum of £100,000.
4. Submit a CV detailing your experience in energy improvement related work
5. List your area(s) of specialisms

Email the completed application form and supporting documentation to CIBSE Certification at