TM44 air-conditioning inspections: the duty estates teams forget
Any building whose air-conditioning totals more than 12 kW of cooling output must have a statutory inspection by an accredited energy assessor every five years. It is the most widely breached energy regulation in UK commercial property — usually discovered mid-transaction, at the worst possible moment.
The legal duty in brief
The requirement comes from the Energy Performance of Buildings Regulations, with CIBSE's TM44 guidance defining the inspection methodology — hence the shorthand. The building "controller" (usually the occupier for leased space, the landlord for common plant) must hold a valid inspection report, lodged on the national register, refreshed at least every five years. New systems must be inspected within five years of installation.
Compliance rates are poor — government's own commissioned research has repeatedly found a substantial majority of in-scope systems uninspected. That is partly ignorance of the aggregation rule (see the FAQs) and partly because no annual process surfaces the duty. It tends to emerge when a solicitor's due diligence checklist asks for the report.
What the inspector actually examines
- Plant condition and sizing — whether installed cooling capacity bears any relationship to the loads it serves. Oversizing is endemic and expensive.
- Controls and operation — setpoints, scheduling, and the classic finding of heating and cooling fighting each other in the same zone.
- Documentation — F-Gas records, maintenance regimes, previous reports.
- Efficiency opportunities — the report must include recommendations, which is where TM44 quietly earns its fee: 10–30% cooling energy reductions are routine findings.
A competent inspection is therefore a miniature cooling-system audit. Treated as input to a wider site energy audit, the recommendations get costed and sequenced rather than filed; treated as a certificate to satisfy a solicitor, the value evaporates.
TM44 within a compliance programme
For multi-site organisations we fold TM44 into the wider compliance calendar: inspections aligned with ESOS Phase 4 site sampling so cooling systems are surveyed once for both purposes, findings flowing into the savings register, and renewal dates diarised so the five-year cycle never lapses again. Single-building owners get the same discipline at smaller scale — inspection, lodged report, recommendations costed, renewal date tracked.
Where inspection findings point to plant replacement, timing matters: refrigerant phase-downs keep tightening the economics of older systems, and replacement decisions made with audit data — load profiles, occupancy patterns, tariff structure — consistently come out smaller and cheaper than like-for-like swaps. That analysis is exactly what the audit fee buys.