What does a business energy audit involve?

The basic steps

Audits vary in depth, but most follow the same pattern.

1. Gather the numbers. The auditor asks for 12 months or more of bills, your MPAN and MPRN meter numbers, and any half-hourly data if you have it.
2. Walk the site. They look at lighting, heating, ventilation, refrigeration, compressed air, hot water, office equipment and the building fabric, noting what is on, when, and why.
3. Spot the baseload. This is the energy used when the premises are shut. High overnight use often points to equipment left running.
4. Rank the fixes. You receive a list of actions with estimated cost, saving and payback.
5. Follow up. A good audit leaves a plan with owners and dates, not just a report.

Walk-through example

Suppose a bakery spends £9,000 a year on electricity and finds, from half-hourly data, that overnight use is 2 kW higher than it should be because a proofing cabinet is left on. Running 8 hours a night for 360 nights: 2 kW × 8 × 360 = 5,760 kWh. At the Q2 2026 non-domestic average of 24.51p/kWh, that is 5,760 × £0.2451 = about £1,412 a year. The figures are illustrative, but the sums show why an audit starts with the quiet hours.

Who has to do one

The government's Energy Savings Opportunity Scheme (ESOS) is the formal version. It applies to large UK undertakings: those with 250 or more employees, or turnover above £44 million and a balance sheet above £38 million. For the current phase the qualification date is 31 December 2026 and the notification deadline is 5 December 2027. The assessment must cover at least 95% of total energy use, and a lead assessor must be appointed unless, for example, the organisation uses less than 40,000 kWh of energy or holds ISO 50001 covering 95% of its energy.

Small and medium businesses outside a qualifying group are not in scope, though they can carry out an assessment voluntarily. Our business energy audit guide goes further.

Cost and quality

We have not found a reliable published price for small-business audits, so we do not quote one. Ask for a fixed fee, the assessor's qualifications, a sample report, and whether the adviser also sells equipment or energy contracts, which can colour the advice. If a supplier, installer or broker offers a free audit, ask what it is selling and treat the recommendations with that in mind.

You can run a basic audit yourself: compare your last three bills, read the meter at close and at opening, and walk round asking what truly needs to be on.

Making the report useful

Ask for actions sorted by payback, with the assumptions written down: the unit rates, operating hours and equipment ages used. Check that quick wins, such as controls and scheduling, appear before expensive hardware. Request raw numbers in a spreadsheet if you can, so you can update them when your tariff changes. Finally, agree a date to review progress. The savings only arrive when somebody owns each action.

Next steps

• Collect 12 months of bills and check them with our guide to reading your bill.
• Consider energy monitoring to see usage by the half hour.
• Start with lighting and heating, the usual first wins.

Biz Energy is independent and not affiliated with any supplier, broker or comparison site, and takes no commission. This is general information, not legal, tax or financial advice.