Apr 8, 2024

Everything You Need To Know About ESOS

Confused about ESOS compliance? Know the deadlines, benefits, and how to achieve compliance with our help. Reduce costs, save energy, and go green!

Everything You Need To Know About ESOS

The Energy Savings Opportunity Scheme (ESOS) is a mandatory energy assessment program implemented by the Environment Agency in the UK. In this article, we will delve deeper into what exactly ESOS is and impart everything you need to know about ESOS compliance. This comprehensive guide will help you navigate the latest developments, updated deadlines, and how our expertise can help your business implement ESOS in the most effective way possible.

What is ESOS?

ESOS is an undertaking by the UK government and is designed to optimise energy efficiency and reduce carbon emissions for large scale organisations based in the UK. By opting for ESOS, business organisations can identify potential areas for development and improve their energy consumption patterns. This leads to significant cost savings for businesses, while leaving a smaller carbon footprint.

ESOS Meaning

The acronym "ESOS" stands for "Energy Savings Opportunity Scheme." The name itself clearly gives away the core objective of the program, which is to identify opportunities within organisations to save and optimise energy usage and reduce the  environmental impact.

ESOS Phase 3

Currently, the UK is operating under ESOS Phase 3, which commenced in April 2016.  Recently there has been an extension of the ESOS Phase 3 compliance deadline. It is offering organisations the necessary time to conduct mandatory energy audits. The new deadline for account registration is June 5th, 2024. The notification of compliance is  due by August 6th, 2024.

ESOS Reporting

ESOS Reporting Requirements

Organisations qualifying for ESOS participation must submit a completed ESOS qualification questionnaire to the Environment Agency. The purpose of the questionnaire is to determine whether an energy audit is required or not. In case it is mandatory to conduct an audit, the organisation will have to submit a detailed ESOS assessment report within a given period of time.

ESOS Phase 3 Deadline Extension 

Organisations looking to apply for ESOS Phase 3 compliance are in luck! The initial deadline of December 5th, 2023 has been extended by the Environment Agency and shifted to June 5th, 2024 for account registration. This gives ample time and opportunity to complete the process. However, gaining complete compliance follows a two-step process.

Two-Step ESOS Phase 3 Compliance Process:

To obtain total compliance with the revised deadline, organisations must go through a two step process, which is as follows:

  • Registration: As per announcement, organisations must complete their account registrations on the Environment Agency's portal mandatorily by June 5th, 2024.
  • Notification: Once the registration is complete, a notification of compliance needs to be submitted by August 6th, 2024. This notification acts as a testament to the fact you have fulfilled your ESOS obligations and informs the Environmental Agency accordingly.

It's crucial to understand and adhere to both steps to achieve full ESOS Phase 3 compliance.

ESOS Energy Audit

The core component of ESOS compliance is the energy audit which is mandatory. This audit, conducted by a qualified and accredited ESOS Lead Assessor, evaluates the organisation's energy consumption across its buildings, operations, and processes in a comprehensive manner. The objective of the audit is to identify areas for improvement and recommend cost-effective solutions for optimising energy usage.

ESOS Auditor

Selecting a qualified and experienced ESOS Lead Assessor is essential for a thorough ESOS assessment. The auditor should have a thorough understanding of ESOS regulations and possess the necessary skills to conduct a comprehensive energy audit.  OAK Network boasts a team of highly skilled experts who can guide your organisation through the entire ESOS process, ensuring a complete hassle free experience.

ESOS Guidance

The Environment Agency provides guidance documents and resources to help organisations navigate the entire ESOS process. The resources include information on qualification criteria, compliance requirements, and best practices for conducting energy audits.

ESOS Compliance

ESOS Compliance for Businesses

Compliance with ESOS is compulsory for qualifying organisations operating in the UK.  Failure to comply can result in enforcement action from the Environment Agency, which includes financial penalties as well. 

Apart from the regulatory necessities, ESOS compliance offers a plethora of benefits for businesses, including reduced energy costs, improved operational efficiency, enhanced sustainability and compliance with environmental regulations.


ESOS Survey

The qualification questionnaire that organisations have to submit to the Environmental Agency primarily acts as an ESOS survey. By obtaining detailed information regarding an organisation's size, energy consumption, and operational activities, the survey determines the applicability of ESOS and hence the necessity for an energy audit.

ESOS Regulations

The Environment Agency publishes detailed ESOS regulations that outline the programme's requirements, qualification criteria, and compliance procedures. It is imperative for organisations and businesses to stay updated on these regulations so that they meet all compliance obligations.

ESOS Phase 2

Understanding the context of ESOS Phase 3 is important.  ESOS Phase 2, which ran from April 2011 to April 2016, established the foundation for the current phase.  

Key takeaways from ESOS Phase 2 include:

  • Increased awareness of energy efficiency: ESOS Phase 2 was quite successful in raising awareness about the importance of energy efficiency among large businesses in the UK.
  • Identification of significant energy-saving opportunities: The mandatory energy audits conducted during Phase 2 identified substantial potential for energy savings across various sectors.
  • Improved compliance: The experience gained during Phase 2 has paved the way for a much more streamlined and efficient compliance process for Phase 3.

How Can OAK Network Help You Achieve ESOS Compliance?

The OAK Network is your one-stop shop for all things related to ESOS. Our team of experts and energy management professionals can guide your organisation through every step of the compliance journey. 

Here's how we can help:

  • ESOS Qualification Assessment: Our team of experts can help determine whether your organisation qualifies for ESOS participation by analysing your energy consumption data and operational activities through monitoring real time data and energy management with AI integration.
  • ESOS Reporting and Documentation: We will guide you all the way through the cumbersome ESOS documentation and reports to ensure timely and compliant submissions to the Environment Agency.
  • Energy Saving Opportunity Identification: Our team will analyse the audit reports and pinpoint specific opportunities to reduce your organisation's energy consumption.
  • Development of Energy Management Strategies: We will collaborate with you to develop a customised energy management strategy that aligns with your business goals and budget.
  • Implementation of Energy-Saving Measures: OAK experts can assist you in implementing the identified energy-saving measures, ensuring maximum impact on your energy efficiency and potential cost savings.
  • Ongoing Support: We offer ongoing support to ensure your organisation maintains ESOS compliance and continues to optimise its energy use over the long term.

By partnering with OAK Network, you gain a team of dedicated energy management professionals who can simplify the ESOS compliance process and empower you to achieve significant energy savings that can take your business to the next level.


ESOS plays a vital role in driving energy efficiency and sustainability within the UK business landscape. By understanding the program's requirements, deadlines, and the benefits of compliance, organisations can navigate ESOS effectively. Moreover, partnering with a leading energy management service provider like OAK Network can streamline the process, ensure compliance, and unlock the full potential of ESOS for the sustainability goals of your business.

Don't wait until the deadline! The extended deadline for ESOS Phase 3 compliance offers a valuable window of opportunity to get started. Contact the OAK Network today to discuss your ESOS requirements and explore how our experts can help your organisation achieve compliance and unlock significant energy savings. Together, we can enhance the quality of your business and build a more sustainable future.

Book a Demo with The OAK Network today!

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