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 Regulations 2012 implement the EU Energy Performance of Buildings Directive in England and Wales. Article 15 required member states to inspect air conditioning systems 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, and the report is public on the non-domestic MEES register, which increasingly drives lettability decisions.
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 pre-2008 that have never been inspected
- Systems that have undergone significant modification since the last inspection
Comfort cooling systems, VRF, chillers, packaged rooftop units and split systems are all in scope. Process cooling for industrial use is out of scope.
Level 3 vs Level 4
Level 3 — simple systems, packaged units, splits and small VRF. Most commercial offices fall here.
Level 4 — complex central plant, chillers, BMS-controlled systems, large multi-zone VRF. Required for anything above roughly 500 kW aggregate or where the system includes a chiller.
The wrong-level assessor produces a report that will not lodge on the register.
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 vs CIBSE TM46
- Recommendations for efficiency improvement — ranked by payback
The report is a written document with clear recommendations, an overall efficiency rating, and a next-due date.
Lodging on the register
The assessor lodges the report on the non-domestic energy performance register within 3 months of inspection. The duty holder receives a report reference number. Enforcement officers check the register — not paper certificates.
F-Gas: a separate regime
Regulation (EU) 517/2014 (retained) governs fluorinated greenhouse gases. Leak check frequency depends on refrigerant charge in CO2-equivalent tonnes:
- 5–50 tCO2e — every 12 months
- 50–500 tCO2e — every 6 months
- >500 tCO2e — every 3 months (or 6 with a fixed leak detection system)
All F-Gas work must be carried out by a REFCOM-registered contractor with individually certified engineers. Records must be kept for a minimum of 5 years and made available to the Environment Agency on request.
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 the HSE treat it as the compliance benchmark for kitchen grease extract and general ductwork.
Kitchen extract cleaning frequency by use:
- Heavy use (12+ hours/day) — quarterly
- Moderate use (6–12 hours) — every 6 months
- Light use (2–6 hours) — annually
Post-clean evidence includes photographic before/after and a deposit thickness test (target <200 microns average).
Evidence pack
- Current TM44 report and lodgement reference
- F-Gas leak check records for every system above 5 tCO2e
- REFCOM certificate for your refrigeration contractor
- TR/19 cleaning certificates with deposit thickness tests
- PPM schedule for AHUs, chillers, boilers
- Airflow commissioning reports post 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 risk on a non-compliant EPC register entry is much larger.
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
