The Energy Performance of Buildings Regulations 2012 require a TM44 inspection every 5 years for air conditioning systems with an effective rated output above 12 kW. The report must be lodged on the non-domestic MEES register within 3 months of inspection. F-Gas leak checks apply separately and are based on refrigerant charge size.
Why TM44 exists
The Energy Performance of Buildings (England and Wales) Regulations 2012 require air conditioning systems above a threshold output to be inspected for energy efficiency. In the UK that inspection follows CIBSE TM44.
The purpose is not safety, it is energy performance. But the regulation is enforced with fixed penalties, the report is lodged on the central non-domestic register, and an absent or lapsed TM44 report increasingly shows up in lease due diligence and MEES conversations. HVAC is the line most often bundled into a general FM contract and least often actually checked.
If you are assembling the whole statutory picture for a building rather than fixing one line, start with the UK duty holder compliance guide.
Who needs one
Any air conditioning system with an effective rated output above 12 kW, including:
- Single systems above 12 kW
- Multiple systems in the same building where the aggregate exceeds 12 kW
- Systems installed before 2008 that have never been inspected
- Systems significantly modified since the last inspection
Comfort cooling, VRF, chillers, packaged rooftop units and split systems are all in scope. Process cooling for industrial use is out of scope.
The inspection is required at intervals not exceeding five years. Aggregation is where buildings get caught: six 3 kW splits across three floors is an 18 kW system for TM44 purposes, even though no single unit is close to the threshold.
Level 3 versus Level 4
| Feature | Level 3 | Level 4 |
|---|---|---|
| Typical systems | Packaged units, splits, small VRF | Chillers, BMS-controlled central plant, large multi-zone VRF |
| Typical building | Offices, retail, small commercial | Large offices, hospitals, universities, campuses |
| Assessor accreditation | Level 3 air conditioning energy assessor | Level 4 air conditioning energy assessor |
| Depth | Component inspection, controls review, sizing check | Full system analysis, plant efficiency, distribution and control strategy |
The wrong-level assessor produces a report that will not lodge on the register. Confirm the accreditation level against the plant before you accept the quote, not after the visit.
What the inspection covers
- System documentation and design intent
- Age and remaining service life of major components
- Effectiveness of controls and BMS integration
- Refrigerant type and F-Gas compliance
- Maintenance regime and log book
- Energy performance benchmarks against CIBSE TM46
- Recommendations for efficiency improvement, ranked by payback
The report is a written document with clear recommendations, an overall efficiency assessment and a next-due date. Recommendations are advisory, not mandatory, but they are visible to anyone who pulls the register entry.
Lodging on the register
The assessor lodges the report on the non-domestic energy performance register and the duty holder receives a report reference number. Enforcement officers check the register, not paper certificates. Always ask for the lodgement reference, not just the PDF. A report that exists only as a file on your contractor's server does not evidence compliance.
F-Gas: a separate regime
Fluorinated greenhouse gas rules sit alongside TM44 and are enforced separately by the Environment Agency. Leak check frequency depends on refrigerant charge in CO2-equivalent tonnes:
| Charge (tCO2e) | Leak check frequency | With fixed leak detection |
|---|---|---|
| 5 to 50 | Every 12 months | Every 24 months |
| 50 to 500 | Every 6 months | Every 12 months |
| Over 500 | Every 3 months | Every 6 months, detection system mandatory |
All F-Gas work must be carried out by a registered contractor with individually certified engineers. REFCOM is the most widely recognised UK registration scheme. Records must be kept for a minimum of five years and made available on request. Keep the equipment log per system, with charge, refrigerant type, engineer certificate number and date, rather than a folder of visit sheets.
TR/19 ventilation hygiene
BESA TR/19 Guide to Good Practice covers internal cleanliness of ventilation systems. It is not a statutory instrument, but insurers and enforcing officers treat it as the compliance benchmark for kitchen grease extract and general ductwork. A kitchen fire claim declined on the basis of an inadequate extract clean is a far larger loss than the cleaning contract that prevented it.
| Kitchen extract use | Hours per day | Cleaning frequency |
|---|---|---|
| Heavy | 12 or more | Quarterly |
| Moderate | 6 to 12 | Every 6 months |
| Light | 2 to 6 | Annually |
Post-clean evidence should include photographic before and after coverage and a deposit thickness test. TR/19 Grease sets a mean deposit thickness target below 200 microns. Specify "TR/19 Grease with pre and post verification" in the contract, because a generic cleaning certificate is what insurers reject.
Where ductwork penetrates compartment walls, cleaning access panels can breach fire stopping. That is a finding for whoever holds your fire risk assessment, and it falls between contractors more often than any other item.
Evidence pack
- Current TM44 report and lodgement reference for every building over threshold
- F-Gas leak check records for every system above 5 tCO2e
- Contractor F-Gas registration certificate, for example REFCOM
- TR/19 cleaning certificates with deposit thickness tests
- PPM schedule for AHUs, chillers and boilers, mapped to SFG20
- Airflow commissioning reports after any refurbishment
TM44 is easy to overlook because there is no visible failure mode. The system keeps working whether it has been inspected or not. The penalty is small. The letting and insurance risk from a gap in the record is much larger.
Related reading: the hotel statutory compliance checklist and the local authority estates checklist show where TM44 and F-Gas sit alongside fire, water and electrical duties, and the contractor vetting guide covers how to check an F-Gas registration properly.
Working with TICDesk
TICDesk is a UK procurement desk for testing, inspection and compliance work. Tell us the plant, the building and your deadline, and we introduce up to three vetted HVAC and refrigeration providers with the right accreditation level, typically within 48 hours. The service is free to the client and TICDesk earns a success fee from the contractor. Visit our HVAC desk or open a brief.
Frequently asked
Which air conditioning systems need a TM44?
Any system with an effective rated output over 12 kW, including packaged splits where the aggregate rated output across the same building or common ownership exceeds 12 kW.
How often is a TM44?
Every 5 years. The report must be lodged on the non-domestic energy performance register within 3 months of the inspection date.
Who can carry out a TM44?
A CIBSE-accredited or ECMK-registered Level 3 or Level 4 air conditioning assessor. Level 3 covers simple systems; Level 4 is required for complex central plant and BMS-controlled systems.
What is the penalty for not having a TM44?
A fixed penalty of £300 per building, plus continued liability until compliance. Local Weights and Measures Authorities enforce.
Sources & further reading
