Energy Savings Opportunity Scheme (ESOS)
A government initiative helping large UK organisations identify and implement energy-saving measures, reduce carbon emissions and improve operational performance and resilience.What is Energy Savings Opportunity Scheme (ESOS)?
The Energy Savings Opportunity Scheme (ESOS) is a mandatory energy assessment scheme for large UK organisations, designed to help them identify practical energy-saving opportunities, reduce carbon emissions and improve operational performance and resilience.
The scheme requires qualifying organisations to assess the energy used by their buildings, industrial processes and transport every four years. These assessments identify practical and cost-effective opportunities to improve energy efficiency, reduce consumption and lower operating costs and carbon emissions.
Beyond compliance, ESOS provides valuable insight into where energy reduction initiatives can deliver cost savings, strengthen operational resilience and support progress towards net zero goals.
Get in touch
Contact our compliance team to discuss your ESOS compliance requirements
At Equans, we make ESOS compliance straightforward
Our team can support every stage of the process, helping organisations not only meet regulatory requirements but also turn energy assessments into investable energy reduction and decarbonisation programmes.
Data collection and energy audits
Reporting
Action planning
Implementing energy saving measures
What are the current ESOS deadlines?
Final Phase 3 progress update – 5 December 2026
Although the main Phase 3 compliance deadline has passed, organisations that qualified for Phase 3 still have ongoing obligations, and must report progress updates annually on the actions included in their ESOS Action Plan. The second and final Phase 3 progress update must be submitted by 5 December 2026. It should provide information about the energy-saving actions implemented during the reporting period and must be signed off by a board-level director or equivalent.
ESOS Phase 4 compliance deadline – 5 December 2027
The Phase 4 compliance period is now in progress, with the notification of compliance due by 5 December 2027. Qualifying organisations will need to assess their energy consumption, identify cost-effective energy-saving opportunities and submit the required compliance information.
Why prepare for ESOS Phase 4 early?
Preparing for Phase 4 early can help organisations improve the quality of their energy data, reduce compliance risk and maximise the value of the assessment process. Starting early also provides more time to identify, evaluate and implement energy-saving opportunities.
ESOS Phase 4: how to turn energy opportunities into investable projects
ESOS Phase 4 presents an opportunity for organisations to turn identified energy-saving measures into investable projects that deliver real value.
Who needs to comply with ESOS?
ESOS applies to large organisation in the UK who must meet one or more of the following criteria to participate:
- Employees more than 250 employees
- Has an annual turnover of more than £44 million
- Has an annual balance sheet total of more than £38 million
How Equans can help
With extensive experience in ESOS compliance, Equans provides support throughout the compliance process. We help organisations meet their regulatory obligations while identifying practical opportunities to reduce energy consumption, operating costs and carbon emissions.
Our services include:
We gather, validate and analyse energy consumption data, providing the robust information needed to support compliance and identify areas for improvement.
We prepare the required ESOS reports and compliance information and support submission to the Environment Agency or relevant regulatory bodies.
Our qualified specialists conduct detailed energy audits to identify practical and cost-effective energy-saving opportunities tailored to your organisation.
We help organisations develop their ESOS Action Plans, monitor the implementation of agreed measures and prepare the required annual progress updates.
We help turn the opportunities identified through ESOS into a prioritised and practical programme of work, supporting measurable energy, cost and carbon savings.
ESOS assessments must be reviewed by a board-level director and approved by a certified ESOS Lead Assessor. As experienced assessors, we ensure your assessment is signed off by one of our experts. We also handle the submission of compliance to the appropriate regulatory body, Additionally, we provide a detailed report outlining your organisation’s energy usage and potential savings.
Why choose Equans?
We help organisations get more from ESOS than compliance alone.
By combining energy assessment expertise with practical delivery capability, we can support you from identifying opportunities through to implementing energy-saving and decarbonisation measures.
Whether you are completing your final Phase 3 progress update or preparing for Phase 4, our energy and sustainability specialists can help you manage your obligations and make the most of the opportunities identified through ESOS.
Working with Equans can help you:
- Meet your ESOS obligations with confidence
- Identify and prioritise practical energy-saving opportunities
- Reduce energy consumption and operating costs
- Turn assessment findings into deliverable programmes of work
- Support wider carbon reduction and net zero objectives
- Maintain compliance throughout the ESOS cycle
Delivering net zero from strategy to delivery
ACT NOW FOR A RESILIENT WORLD
Organisations are under growing pressure to achieve net zero carbon, reduce energy costs, and modernise ageing estates - all while navigating complex regulation, funding constraints and increasing physical climate risk.
Carbon Shift is Equans’ specialist decarbonisation and net zero delivery offer, designed to turn ambition into practical, investable, and deliverable programmes.
