About ESOS

ESOS is a mandatory energy assessment scheme for organisations in the UK that meet the qualification criteria. The Environment Agency is the UK scheme administrator.

Organisations that qualify for ESOS must carry out ESOS assessments every 4 years. These assessments are audits of the energy used by their buildings, industrial processes and transport.

The ESOS audit is designed to identify tailored and cost-effective measures to allow participating businesses to save energy and achieve carbon and cost savings. The audit costs are aimed to be significantly outweighed by the savings from implementing the recommendations.

Which organisations does ESOS apply to

ESOS applies to large UK undertakings and their corporate groups. It mainly affects businesses but can also apply to not-for-profit bodies and any other non-public sector undertakings that are large enough to meet the qualification criteria.

Your organisation qualifies for ESOS if it meets the ESOS definition of a large undertaking*:

• Employs 250 or more people, or

• Has an annual turnover in excess of £44 million, and an annual balance sheet total in excess of £38 million

ESOS with Engineered Efficiency

We deliver more than compliance — we protect and enhance investment value.

Our assessments, led by senior engineers with deep expertise in large and complex assets, translate regulatory requirements into strategic advantage. We help businesses understand how compliance can be leveraged to strengthen performance, manage risk, and support long-term value creation.