Technical review: Current accredited TM44 assessor to be confirmed before publication
Last reviewed: 4 September 2026
If you manage a commercial building, you may have searched for “TM44 requirements”, “TM44 regulations UK”, “TM44 inspection frequency” or “is a TM44 inspection a legal requirement?”. These questions usually arise when a facilities manager is preparing for an audit, taking over a building, reviewing an expired report or planning a maintenance programme.
This guide explains the main requirements in plain English for building owners, landlords, occupiers and facilities managers in England and Wales. It is general information, not legal advice. Whether a particular system is in scope depends on its effective rated output, control arrangements, building use and available records.
What is a TM44 inspection?
A TM44 inspection is an energy-efficiency inspection of an air-conditioning system. The assessment methodology is based on CIBSE TM44, Inspection of air conditioning systems: a guide to EPBD compliance.
The purpose is to understand how the system is operating and identify practical opportunities to improve performance. An assessor may review the system’s likely efficiency, controls, maintenance condition, sizing and operation under normal building conditions. The resulting report can help reduce avoidable energy use, operating cost and carbon emissions.
A TM44 inspection is not the same as routine servicing, refrigerant leak testing or a repair visit. The inspection may identify a dirty filter, a faulty sensor or an inappropriate control setting, but physical work is normally arranged separately.
Which systems are covered?
The key threshold is an effective rated output of more than 12 kW. Several units below 12 kW can be treated as one system when they are under common control and their combined output is above 12 kW.
Check manufacturer rating plates, O&M manuals, commissioning documents, maintenance schedules, equipment registers and design drawings. If the capacity is unclear, it should be established through appropriate inspection, calculation and enquiries by a suitably qualified person. Floor area alone is not a reliable substitute because occupancy, glazing, orientation, equipment loads and operating hours change cooling demand.
How often is an inspection required?
An in-scope system must be inspected at intervals of no more than five years. Plan ahead for locating the previous report, checking register status, arranging safe access, gathering records, coordinating tenants and reviewing recommendations. Systems first put into service on or after 1 January 2008 generally require their first inspection within five years of being put into service. Historic deadlines for older systems may already have passed, so use the latest official guidance for a current decision.
Who is responsible?
The person who controls the technical operation normally carries responsibility. Depending on the property and contract, this may be the owner, landlord, occupier, facilities-management company or another named operator.
The person who adjusts a thermostat is not automatically the responsible person. The relevant question is who has authority over operation, maintenance and technical management. Outsourcing routine servicing does not automatically remove an owner’s responsibility; landlord and occupier duties may run in parallel.
What does the inspection involve?
Pre-inspection review
The assessor requests the address, capacities, equipment schedules, previous report, maintenance history, control information and operating pattern. Good records reduce uncertainty.
Asset and system survey
The assessor identifies accessible indoor and outdoor units, central plant, distribution equipment and controls. They check labels, system boundaries, zoning and sensors.
Controls and operating review
The assessment considers schedules, set points, zoning and control sequences. Common issues include simultaneous heating and cooling, operation outside occupied hours and overridden controls.
Maintenance and condition review
Visible faults or conditions that may reduce efficiency are recorded. Cleaning, repair or refrigerant work is normally a separate scope.
Cooling-load and sizing review
The installed system is considered in relation to cooling demand. Oversizing can cause inefficient operation; undersizing can affect comfort.
Report, lodgement and handover
The assessor prepares a building-specific report, lodges it on the relevant register and gives it to the person responsible. Retain the reference number with energy and maintenance records.
What must the report contain?
The GOV.UK guide states that a report should include the building address, assessor name, employer or trading address, inspection date, accreditation scheme and valid reference number. Technical content should explain likely efficiency, faults, maintenance adequacy, controls, system size relative to cooling load, typical operation and improvement opportunities.
Is TM44 the same as maintenance?
No. Maintenance, cleaning, safety checks, refrigerant leak testing and repairs may be required under other obligations. TM44 focuses on energy performance and recommendations. If a repair is identified, agree a separate scope, risk assessment and price.
Must every recommendation be implemented?
There is no legal requirement to implement every recommendation. Nevertheless, record each item, assign an owner, estimate cost and benefit, and document whether it was accepted, deferred or rejected. Recommendations may support a wider decarbonisation plan, but a TM44 report is not a complete net-zero strategy.
What happens when responsibility changes?
The latest report should be passed to anyone taking over responsibility. If a new operator has not received it, the system may need inspection within three months of the change in control. Include the report, reference number, system list and outstanding recommendations in the property handover pack.
Are rules different in London or Birmingham?
The core England and Wales requirements do not change by city. Searches for “TM44 inspection London”, “TM44 inspection Birmingham”, “TM44 inspections Leicester”, “TM44 inspections Nottingham” and “TM44 inspections Derby” usually indicate a need for local availability and relevant experience. Providers should explain genuine coverage without creating thin doorway pages.
Final compliance checklist
- Is the combined effective output above 12 kW?
- When was the last report completed and lodged?
- Who controls technical operation?
- Is the assessor currently accredited?
- Will the report be registered and referenced?
- Are plant rooms and tenant spaces accessible?
- Which recommendations require separate work?
- Where will the report be stored?
Need a TM44 inspection?
See UEC Energy’s TM44 inspection service or contact the team. Provide the building address, approximate capacity, previous report date and access restrictions.
Sources: GOV.UK air-conditioning inspection guide and CIBSE TM44.
Practical questions before you book
What if the previous report is missing?
Start by checking the building logbook, facilities-management portal, landlord records and the previous assessor’s correspondence. If no valid report can be located, do not assume that an old invoice or service sheet proves compliance. Ask an accredited assessor to review the available evidence and advise whether a new inspection is needed.
Can one report cover several tenants?
It can, where the systems are properly identified and the control arrangements are clear. The report should distinguish landlord-controlled central plant from tenant-installed equipment. Give the assessor a current asset schedule and lease responsibility matrix rather than asking them to infer ownership during a short site visit.
What should happen after the report?
Nominate an owner for each recommendation, record the decision and set a review date. Keep evidence of completed controls changes, maintenance and capital work. This makes the next inspection more useful and prevents the same issue being rediscovered without explanation.
Does a report guarantee lower bills?
No. The report identifies opportunities. Actual energy and carbon outcomes depend on implementation, occupancy, weather, tariffs, maintenance and control quality. Present projected benefits as estimates and verify completed measures with reliable data.