Statutory 5-year inspection — commercial AC systems over 12kW

TM44 Air Conditioning Inspection London

Statutory 5-year air conditioning energy inspection for commercial properties with AC systems over 12kW combined. Coordinated through CIBSE / Elmhurst / Quidos / Sterling accredited assessors, with F-Gas remedial work delivered in-house (REF1024168).

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A TM44 inspection is a statutory energy efficiency assessment of an air conditioning system, required under the Energy Performance of Buildings (England and Wales) Regulations 2012 (SI 2012/3118), Part 4. The obligation applies to any AC system with an effective rated output of more than 12kW — measured across all units under the same person's control in a building, not per individual unit. Inspections must be repeated at intervals not exceeding five years and must be carried out by an energy assessor accredited through one of four government-approved schemes: CIBSE, Elmhurst Energy, Quidos, or Sterling Accreditation. The inspection report is lodged on the national Energy Performance of Buildings Register and a valid reference number issued. Mainteniq coordinates TM44 inspections through its network of accredited energy assessors and delivers any F-Gas refrigerant and remedial AC work the report recommends through its own certified engineers (Refcom REF1024168).

The 12kW threshold is combined output — not per unit

Under Regulation 17(2) of SI 2012/3118, where a building operator, landlord, or managing agent controls more than one AC unit in a building, those units are treated as a single system for the purposes of the threshold. Ten 2kW wall-split units under one management company's control aggregate to 20kW — well above the 12kW trigger. The key question is not the size of any individual unit, but whether the person responsible for the building controls AC equipment whose combined cooling capacity exceeds 12kW. A building with a single 5kW reception unit controlled by one person may be below threshold; a building with twelve 2kW units all under one facilities manager is not.

TM44 Legal Requirements at a Glance

RequirementDetail
Applies toAC systems with an effective rated output of more than 12kW — combined across all units under the same person's control.
Inspection frequencyAt least every 5 years (Reg 18(1)).
Carried out byAn energy assessor accredited through one of four approved schemes: CIBSE, Elmhurst Energy, Quidos, or Sterling Accreditation.
Report lodged onEnergy Performance of Buildings Register — a valid reference number must be included in the report.
Primary penalty£300 fixed penalty per breach, imposed by Trading Standards (local weights and measures authority — Reg 34(1)).
Failure to produce report on requestAdditional £200 fixed penalty for failing to produce the inspection report to a Trading Standards Officer within 7 days of request.
Building types in scopeAll buildings — Part 4 contains no explicit residential exemption. Commercial premises are the primary target, but residential blocks with communal AC under single management control are also in scope.
Optimisation requirementSince SI 2020/1422, inspection reports must assess the system's capability to optimise performance under typical operating conditions (Reg 19(2A)).
Legal basisEnergy Performance of Buildings (England and Wales) Regulations 2012, SI 2012/3118, Part 4, Reg 17(2) and Reg 18(1).

Source: gov.uk — A guide to air conditioning inspections in buildings (updated September 2024)

What a TM44 Inspection Assesses

AC system type, age, and condition — including split systems, VRF/VRV, chillers, and air handling units

Effective rated cooling output — confirming whether the 12kW combined threshold is met

Energy efficiency of the system under typical operating conditions

Optimisation opportunities — including controls, zoning, scheduling, and temperature set-points

Sizing assessment — whether the installed system is appropriately sized for the space it serves

Maintenance history — assessing whether the system is being maintained to preserve performance

Recommendations for improvement — written schedule of energy-saving measures with indicative savings

Who Needs a TM44 Inspection

Offices & Commercial Premises

Any office building, business park, or commercial unit where total AC capacity under management control exceeds 12kW. Open-plan offices with multiple ceiling cassettes or rooftop condensers often aggregate well above the threshold.

Retail & Hospitality

Retail units, restaurants, hotels, and leisure venues commonly run central or zoned AC systems well above 12kW. A single hospitality venue with a central air handling unit will almost always trigger TM44.

Healthcare & Education

Hospitals, GP surgeries, care homes, schools, and universities frequently operate large climate control systems. Healthcare and education operators are often unaware that TM44 applies to them.

Residential Block Managing Agents

Build-to-Rent towers, large apartment blocks with communal AC, and serviced accommodation operators controlling central cooling systems are in scope — the 12kW threshold covers combined communal output under single management control.

How Mainteniq Coordinates Your TM44

1

System assessment — confirm you're in scope

We review your AC system inventory — unit types, rated cooling output per unit, and who controls them — to confirm whether TM44 applies and when the next inspection is due.

2

Inspection coordinated through an accredited assessor

We coordinate the inspection through energy assessors accredited with CIBSE, Elmhurst Energy, Quidos, or Sterling Accreditation. The assessor attends site, completes the TM44 assessment, and lodges the report on the Energy Performance of Buildings Register.

3

Report delivered — reference number on the national register

You receive the TM44 inspection report with a valid registration number from the Energy Performance of Buildings Register. We retain a copy for your service records and flag the next due date.

4

F-Gas remedial work delivered in-house

Where the report recommends refrigerant checks, AC servicing, or component replacement, our F-Gas certified engineers (Refcom REF1024168) carry out the remedial work directly — no second contractor needed.

How Mainteniq Coordinates TM44 + Remedial Work

TM44 inspections must be carried out by energy assessors accredited through one of four government-approved schemes: CIBSE, Elmhurst Energy, Quidos, or Sterling Accreditation. Mainteniq does not hold TM44 inspector accreditation directly — we coordinate inspections through our network of accredited assessors and manage the process on your behalf. As F-Gas certified specialists (Refcom REF1024168), our engineers then deliver any refrigerant handling, AC maintenance, or remedial work the inspection report recommends. This single-contractor approach means commercial property managers avoid the time and coordination cost of sourcing two separate suppliers — one for the inspection, one for the follow-up work — under one coordinated Mainteniq contract.

Regulatory Guidance & Standards

gov.uk — A guide to air conditioning inspections in buildingsEnergy Performance of Buildings RegisterCIBSE — TM44 guidance and approved accreditation schemeSI 2012/3118 — Full legislation text

Mainteniq holds Refcom F-Gas certification REF1024168 (valid to March 2029), authorising our engineers to handle refrigerants on all AC systems. TM44 inspections are coordinated through CIBSE-, Elmhurst-, Quidos-, or Sterling-accredited energy assessors.

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Serving commercial properties across London and a 120-mile radius. Inspection coordinated through accredited assessors. F-Gas remedial work delivered in-house.

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TM44 Inspection FAQs

A TM44 inspection is a statutory energy efficiency assessment of an air conditioning system, required under the Energy Performance of Buildings (England and Wales) Regulations 2012 (SI 2012/3118), Part 4. It applies to any AC system with an effective rated output of more than 12kW — measured across all units under the same person's control in a building, not per individual unit. Inspections must be repeated at intervals not exceeding five years. The TM44 refers to the CIBSE technical memorandum (TM44:2012) that defines the inspection methodology for compliance with the Regulations.

Across the whole building — under the control of the same person. Regulation 17(2) of SI 2012/3118 provides that where a single person has control over more than one AC unit in a building, all those units are treated as components of a single system for the purposes of the threshold. Ten 2kW wall-split units under one management company's control aggregate to 20kW — well above the 12kW trigger. The key question is not the size of any individual unit, but whether the responsible person controls AC equipment whose combined cooling capacity exceeds 12kW.

TM44 reports can only be signed off by an energy assessor accredited through one of four government-approved accreditation schemes: CIBSE, Elmhurst Energy, Quidos, or Sterling Accreditation. Mainteniq does not hold TM44 inspector accreditation directly — we coordinate inspections through our network of accredited assessors, then carry out any F-Gas refrigerant work, AC servicing, or remedial maintenance the report identifies. This gives you a single point of contact for the entire TM44 cycle rather than managing two separate contractors.

At least every five years. Regulation 18(1) of SI 2012/3118 requires inspections at regular intervals not exceeding five years. There is no provision equivalent to the CP12 two-month early renewal window — a TM44 inspection must simply occur within five years of the previous one. If the inspection report recommends a shorter interval, that recommendation should be followed. Failure to inspect within the five-year cycle results in a £300 fixed penalty per breach, enforced by Trading Standards.

The inspection report will recommend improvements to the AC system's energy performance and optimisation. Where recommendations involve refrigerant handling — such as leak checking, refrigerant recovery, recharging, or component replacement — that work must be carried out by an F-Gas certified company under UK Fluorinated Greenhouse Gas Regulations. Mainteniq holds Refcom certification REF1024168, which authorises our engineers to carry out this refrigerant work directly. We coordinate the TM44 inspection through an accredited assessor and then deliver the F-Gas remedial work in-house, issuing a single consolidated service record.