Our highest priority is the safety of all our valued customers and colleagues, especially as we face the battle against COVID-19. Please read our coronavirus update here

0345 070 1055

The Energy Savings Opportunity Scheme (ESOS), is a mandatory energy assessment scheme designed to help large enterprises meet their environmental commitments and benefit from cost savings.

Organisations are encouraged to review how energy is being used within the organisation by their buildings, industrial processes and transport, and then identify practical, cost-effective savings opportunities in these areas.

ESOS applies to organisations defined as ‘large undertakings’ that meet the following qualifying criteria:

  • 250 or more employees
  • An annual turnover in excess of 50 million Euro and an annual balance sheet total in excess of 43 million Euro
  • An overseas company with a UK registered establishment which has 250 or more UK employees (paying income tax in the UK)


An ESOS assessment includes:

  • Appointing a lead assessor
  • Assessing your total energy consumption
  • Identifying your areas of significant energy consumption
  • Notifying the Environment Agency
  • Keeping records of how you have complied with ESOS

Qualifying organisations that did not complete and notify a compliance assessment by 5 December 2015 will be in breach of the regulations and at risk of enforcement action and penalties. Organisations that qualify for ESOS must carry out ESOS assessments every 4 years.

ESOS does not require participating organisations to implement the recommended energy saving measures, but it does encourage major energy savings in companies throughout the UK. With around 20 per cent of a company’s annual energy usage currently wasted through inefficient practices, according to figures from the Carbon Trust, ESOS has the potential to influence energy management and behaviour, improving the profitability of organisations and reducing energy demand and carbon emissions across the UK.

How can we help?

Heating and hot water is typically the largest single end-use of energy in a building, so a good starting point for efficiency measures.

For the UK's high percentage of old buildings, investing in high-efficiency condensing boiler technology is an excellent cost-effective measure. Replacing inefficient or ageing non-condensing boiler plant with super-efficient, fully-modulating condensing boilers such as the Gas 220 can cut gas consumption and carbon emissions by a third, transforming the energy performance of a building.

For more information on ESOS, visit the Government's website.