ESOS reporting refers to the Energy Savings Opportunities Scheme, a UK government initiative requiring certain organisations to carry out energy audits. The key word here is “opportunity”, the process is designed to uncover cost-effective ways to save energy and money. While there’s currently no obligation to implement the identified measures, many businesses find the savings too good to ignore.
Who Must Comply with ESOS?
Any UK organisation, including charities, must comply if it meets one of the following criteria:
• Employs 250 or more staff
• Has an annual turnover over £44 million and an annual balance sheet total over £38 million
• Smaller organisations can still choose to participate voluntarily to uncover energy-saving opportunities.
ESOS Compliance What’s Involved?
To comply, organisations must:
1. Calculate total energy consumption across a 12-month period.
2. Identify energy-using areas such as transport, offices, or operational sites.
3. Select representative sites for detailed auditing (not every site must be assessed).
4. Conduct energy audits to highlight savings opportunities.
5. Compile evidence packs from site and summary reports.
6. Have findings reviewed and signed off by a company director.
7. Submit results via the regulator’s MESOS system.
What Happens During an ESOS Audit?
An ESOS site audit involves:
• Profiling energy usage data to spot unusual patterns.
• Site walk-throughs, with access to plant rooms, boiler rooms and roofs.
• Room-by-room assessments covering building fabric, heating, cooling, lighting, hot water, appliances and behaviours.
• Costed recommendations, detailing savings in money and kWh.
• Additional suggestions that may support future refurbishments, net zero targets, or compliance with legislation such as MEES.
Choosing the Right ESOS Lead Assessor
By law, all audits must be reviewed by an accredited ESOS lead assessor. Many organisations prefer using the assessor throughout the process. Qualities to look for include:
• Experience with your type of buildings (e.g. care homes, offices, retail, hotels, schools, nurseries).
• A focus on delivering cost savings, not just compliance.
• Professional environmental qualifications for a holistic approach.
• Independence from equipment installers.
• Strong client testimonials, such as this from JKS Restaurants:
“We really appreciate your approach and efficiency in which this was all carried out. Once again, a big thank you from both myself and Yasmin!”
Next Steps
If your organisation needs to be ESOS compliant or you’d like to unlock energy and cost savings through an audit, then contact us or find more guidance here. We would be happy to discuss how we can support you.