Free resource
The Commercial Energy Audit Checklist
Everything to check before, during and after a site energy audit — scoping, the walk-through, the measurements worth taking, normalising the data, and reporting so the recommendations actually happen. Distilled from our full Energy Audits course.
1 · Before you visit — scoping & data
An audit is won or lost before you arrive. Agree what you're auditing and get the data flowing early.
- Agree the audit level with the client (walk-through vs detailed vs investment-grade) and match it to what they need to decide
- Draw the boundary explicitly: which buildings, processes and meters are in scope — and which are not
- Request 12+ months of gas and electricity bills (half-hourly data if available)
- Request production/occupancy records for the same period — you cannot normalise without them
- Ask for a site plan, a plant list and any previous audit reports
- Book the visit for a day the site is actually running normally
- Confirm site-specific safety requirements (PPE, permits, escorted areas) before arrival
2 · The walk-through
Walk the energy path from the meter to the point of use — and trust your senses.
- Start at the incoming meters and trace each energy stream to its major users
- List the significant energy users (the ~20% of plant that takes ~80% of the energy)
- Listen for compressed-air leaks (hiss), look for steam plumes and dripping traps
- Feel for uninsulated hot pipework, valves and flanges — every hot surface is a running cost
- Note plant running that serves nothing (lights in empty rooms, ventilation in unused areas, idling compressors)
- Check setpoints against actual need: heating and cooling fighting each other, cold stores colder than spec
- Photograph nameplates of major plant (ratings, efficiencies, model numbers)
- Ask the operators what runs overnight and at weekends — then verify against half-hourly data
Frequently asked questions
- What should a commercial energy audit checklist include?
- Five stages: scoping (agree the audit level, boundary, and gather 12+ months of bills plus production or occupancy data), a structured walk-through tracing energy from the meters to the major users, targeted measurements (flue-gas analysis, motor loads, overnight baseload, compressed-air checks), normalised analysis against weather and output, and a report that quantifies every recommendation with costs, savings and paybacks.
- How long does a commercial energy audit take?
- A walk-through audit of a straightforward site is typically a day on site plus reporting time. Detailed audits of complex or industrial sites take several days, plus data analysis either side of the visit. ESOS-compliant audits are sized so that, together with other compliance routes, they cover at least 90% of the organisation's total energy consumption.
- What is the difference between a walk-through and a detailed energy audit?
- A walk-through relies on observation and existing data (bills, half-hourly profiles) to find behavioural waste and obvious faults; it is quick and cheap but its savings estimates are indicative. A detailed or investment-grade audit adds measurement, sub-metering and engineering analysis, producing numbers robust enough to underwrite capital spending decisions.
- Do I need an energy audit for ESOS?
- If your organisation qualifies as a large UK undertaking (250+ employees, or turnover above roughly £44m with a balance sheet above roughly £38m), ESOS requires its energy consumption to be covered by compliant audits, ISO 50001 certification or equivalent routes, and the Phase 4 deadline is 5 December 2027. Smaller organisations have no legal obligation, but the same audit method is how they find savings.