TM44 Air Conditioning Inspections Explained
If your building's air conditioning adds up to more than 12 kW, the law requires an accredited energy assessor to inspect it at least every five years and lodge the report on the national register. This guide explains who the duty falls on, what the threshold means, who may do the inspection, what the report covers, the penalties, and how TM44 fits alongside your maintenance contract. We match businesses with vetted, F-Gas certified contractors, many of whom can arrange an accredited assessor.
The 12 kW threshold and who carries the duty
The threshold is the combined effective rated output of all air conditioning in the building under one person's control, not the size of any one unit. The duty falls on whoever controls the technical functioning of the system — normally the landlord for landlord-provided plant, the tenant where the tenant installed it.
| Scenario | Combined output | TM44 required? | Duty holder |
|---|---|---|---|
| Small shop with two 3.5 kW wall splits | 7 kW | No | — |
| Office with five 3.5 kW splits under one occupier | 17.5 kW | Yes | Occupier who controls them |
| Multi-tenant building, landlord VRF serving all floors | Typically 50–250 kW | Yes | Landlord / managing agent |
| Tenant-installed system in a leased unit | Above 12 kW | Yes | Tenant |
Effective rated output is the manufacturer's cooling capacity under standard conditions. Comfort cooling, including the cooling side of air-to-air heat pumps, counts; dedicated process cooling and refrigeration generally do not.
Every five years — and when the clock starts
Existing systems must hold a report no more than five years old; a new system above 12 kW must be inspected within five years of being put into service. On sale or letting the current report passes to the new controller — if none exists, they must arrange one within three months — and the enforcing authority can demand it within seven days. There is no grace period at expiry, so diarise renewal a few months ahead; assessor availability tightens in summer.
Accredited energy assessors only
The inspection must be carried out by an air conditioning energy assessor registered with a government-approved accreditation scheme: Level 3 for simple packaged and split systems (typically no single unit over 12 kW), Level 4 for complex and centralised systems — VRF/VRV, chilled water, large ducted plant. Most commercial buildings need Level 4. A service engineer's F-Gas certificate does not qualify them, though some contractors employ or partner with an assessor. Verify accreditation on the Energy Performance of Buildings Register before booking, and ask for the lodged report reference afterwards.
What a TM44 inspection covers
The assessor inspects the plant, reviews documentation and produces a report with an efficiency assessment and recommendations — a couple of hours for a simple site, a day or more for a large building.
| Area | What the assessor looks at |
|---|---|
| Inventory | Every system, unit, capacity, refrigerant type and age — reusable for F-Gas and asset registers |
| Sizing | Whether installed capacity matches the cooling load; over-sized plant short-cycles and wastes energy |
| Condition and maintenance | Filters, coils, condensers, insulation, evidence of leaks, and whether maintenance and F-Gas records are in order |
| Recommendations | Practical improvements — controls, maintenance, refurbishment or replacement — with indicative payback where possible |
Penalties and enforcement
Enforcement sits with local trading standards. Failing to hold a valid report, or to produce one within seven days when asked, attracts a fixed penalty — historically £300 per offence and repeatable while the breach continues; treat that as indicative and confirm the current amount. The sharper consequences are usually commercial: a due-diligence request on sale or letting, a lender or insurer condition, or a tenant dispute where a missing report is a visible gap in the compliance file. The report also earns its keep — an independent expert tells you whether your plant is the right size and whether a controls fix or a VRF replacement would pay back; the commercial cost guide helps budget that.
Sources & methodology
- Energy Performance of Buildings (England and Wales) Regulations 2012 and government guidance "Air conditioning inspections for buildings".
FAQs
Get your plant inspected and maintained
Tell us about your building and systems and we match you with vetted, F-Gas certified commercial contractors — many can arrange an accredited TM44 assessor alongside a maintenance contract. Free and without obligation.