KJ Tait

Does My Building Need a TM44 Inspection?

Engineer inspecting commercial air conditioning equipment during a TM44 compliance assessment
Date
25 August 2026

If the air conditioning systems under your control have a combined effective rated output of more than 12kW, you normally need a TM44 air conditioning inspection. The threshold applies to the combined cooling capacity, so several small units can bring a building within scope even when no individual unit exceeds 12kW.

Air conditioning inspections are a legal requirement under the Energy Performance of Buildings (England and Wales) Regulations 2012. The person who controls the operation of the system must arrange an inspection by an accredited air conditioning energy assessor at intervals not exceeding five years.

This guide explains how to determine whether your commercial building requires a TM44 inspection, who is responsible and what information you should check.

Does My Building Need a TM44 Inspection?

Your building is likely to require a TM44 inspection when all the following apply:

  • There is air conditioning within the building.
  • The combined effective rated cooling output is more than 12kW.
  • You control the technical operation of the relevant systems.
  • The system has not been inspected within the last five years.

The regulations apply to air conditioning systems, not simply to large buildings. A small office, shop, clinic or restaurant can therefore require an inspection if several smaller cooling units collectively exceed the threshold.

How Does the TM44 12kW Threshold Work?

For TM44 compliance, the relevant figure is the system's effective rated output. This is the maximum cooling output specified and guaranteed by the manufacturer for continuous operation under the stated efficiency conditions.

Where one person controls the temperature of several individual air conditioning units in a building, those units are treated as components of a single air conditioning system. Their rated outputs must therefore be considered together.

Example: Four Small Split Systems

  • 4 × split air conditioning units
  • 3.5kW cooling capacity per unit
  • Combined cooling capacity = 14kW

Result: TM44 inspection required.

This aggregation rule is one of the most common causes of accidental non-compliance. Property managers may review each unit separately and conclude that none exceeds 12kW, without calculating the combined capacity under their control.

It Is More Than 12kW, Not 12kW or More

The regulatory wording is more than 12kW. A system rated at exactly 12kW does not cross the threshold, while a combined output above 12kW does.

Which Air Conditioning Systems Count?

The definition covers systems that control or lower air temperature. It can also include systems that combine cooling with ventilation, humidity control or air cleanliness.

Systems commonly encountered during commercial TM44 reviews include:

  • Wall-mounted and ceiling-mounted split systems
  • Multi-split air conditioning systems
  • Variable refrigerant flow and variable refrigerant volume systems
  • Packaged air conditioning units
  • Chillers serving fan coil units or air handling systems
  • Comfort cooling serving offices, reception areas and meeting rooms
  • Cooling associated with mixed heating, ventilation and air conditioning systems

Dedicated process refrigeration requires careful consideration. Government guidance is primarily intended to cover refrigeration used to provide cooling for building occupants, although the regulations do not contain a blanket exemption limiting inspections only to comfort cooling. A competent assessor should review unusual or specialist installations individually.

Which Buildings Commonly Require a TM44 Inspection?

The requirement depends on the air conditioning system rather than the building's use, ownership, floor area or EPC rating. Buildings that commonly require TM44 inspections because they frequently contain air conditioning systems exceeding 12kW include:

  • Commercial offices
  • Retail units, supermarkets and shopping centres
  • Hotels, restaurants and leisure facilities
  • GP surgeries, dental practices, clinics and healthcare buildings
  • Schools, colleges and university buildings
  • Warehouses with cooled offices or occupied operational areas
  • Laboratories and life-science facilities
  • Data centres and buildings with IT cooling
  • Mixed-use developments with centrally controlled cooling

A modest building can exceed 12kW surprisingly quickly. The safest approach is to check the installed plant rather than estimating eligibility from floor area or building type.

How Can I Check the Cooling Capacity?

Start by preparing an asset list of every air conditioning unit under the control of the relevant owner, occupier or property manager. Record the manufacturer, model number and rated cooling output for each item.

The cooling capacity may be available from:

  1. The rating plate fixed to the indoor or outdoor equipment
  2. Operating and maintenance manuals
  3. Air conditioning asset registers
  4. F-Gas records
  5. Maintenance contractor records
  6. Manufacturers' technical information
  7. Commissioning records and as-installed equipment schedules

Do not add heating outputs, electrical input powers or refrigerant quantities. The assessment must use the appropriate rated cooling outputs. Model numbers can sometimes contain capacity indicators, but they should be checked against reliable manufacturer information rather than treated as conclusive evidence.

What If the Records Are Incomplete?

Incomplete records do not demonstrate that a building is outside the regulations. An initial compliance review can use photographs of equipment labels, floor plans, maintenance schedules and F-Gas information to identify the installed systems and establish whether the 12kW threshold is exceeded.

Who Is Legally Responsible for the Inspection?

The responsibility sits with the person who controls the technical operation of the air conditioning system. This means more than having permission to adjust a room thermostat.

Depending on the ownership, lease and management arrangements, the responsible person may be:

  • The building owner
  • A commercial landlord
  • An occupier with responsibility under a full repairing and insuring lease
  • A tenant that owns and operates locally installed systems
  • A facilities management or servicing company where the contract assigns technical control

Appointing a maintenance contractor does not automatically remove the owner's or occupier's duty. Government guidance states that a landlord or building occupier may retain a parallel duty to ensure the system has been inspected.

For multi-let properties, responsibility may differ between landlord-controlled central plant and tenant-installed systems. The lease, equipment ownership and actual technical control should be reviewed together.

How Often Is a TM44 Inspection Required?

Qualifying air conditioning systems must be inspected at intervals of no more than five years. The due date should be taken from the previous valid inspection report or, for a newly installed qualifying system, the date on which it was first put into service.

If responsibility for a system transfers and the new responsible person is not given the existing inspection report, the regulations require an inspection within three months of taking control.

Who Can Carry Out a TM44 Inspection?

The inspection must be carried out by an air conditioning energy assessor who is a current member of a government-approved accreditation scheme.

In England and Wales, a valid air conditioning inspection report must be produced and lodged on the Energy Performance of Buildings Register by an accredited assessor. The report includes a unique reference number generated through the register.

A routine maintenance visit, F-Gas inspection or refrigerant leak check does not replace a TM44 inspection. These activities serve different purposes and may be required alongside the statutory energy assessment.

What Happens During a TM44 Inspection?

The assessor reviews accessible parts of the air conditioning system and considers how efficiently the system is likely to operate. The inspection normally examines:

  • Installed air conditioning plant and system configuration
  • Equipment condition and maintenance arrangements
  • Control settings and operating schedules
  • The relationship between installed capacity and cooling demand
  • Opportunities to improve system efficiency
  • Faults or control issues visible during the inspection
  • The system's ability to optimise performance under typical operating conditions
  • Potential replacement options and alternative solutions

The resulting report provides findings and recommendations. There is no general legal requirement under the TM44 provisions to implement every recommendation, but acting on suitable measures can reduce energy consumption, operating costs and carbon emissions.

What Documents Should I Prepare?

Good records help the assessor understand the system and can make the inspection more efficient. Useful information includes:

  • The previous air conditioning inspection report
  • A current air conditioning asset register
  • Operating and maintenance manuals
  • Maintenance and service records
  • F-Gas records
  • Record drawings and system schematics
  • Controls descriptions and operating schedules
  • Commissioning information
  • Details of changes made since the previous inspection

The most recent inspection report must be retained. It should be kept with the building log book, maintenance information or other building energy records and passed to any new person taking control of the system.

What Are the Risks of Not Having a Valid Inspection?

Local weights and measures authorities are responsible for enforcing the air conditioning inspection requirements in England and Wales. Enforcement can include requiring documents to be produced and issuing penalty charge notices where the regulations have not been met.

Non-compliance can also create practical problems during:

  • Property acquisitions and disposals
  • Lease negotiations and changes of occupier
  • Compliance and facilities management audits
  • ESG and energy performance reviews
  • Refinancing and investor due diligence
  • Changes of managing agent or maintenance contractor

The greater commercial risk is often poor control of the underlying asset information. If no one can confirm the system capacity, responsible person, previous inspection date or report location, the property owner cannot readily demonstrate compliance.

A Practical TM44 Compliance Check

Facilities and property managers can use the following process to establish the building's position:

  1. Identify every air conditioning system within the property.
  2. Confirm which person or organisation controls each system.
  3. Obtain the manufacturer and model number for each unit.
  4. Verify the rated cooling output from reliable records.
  5. Add together the outputs of units under common control.
  6. Check whether the combined output is more than 12kW.
  7. Locate the latest inspection report and confirm its date.
  8. Arrange an accredited inspection if the report is missing, expired or due for renewal.

For a property portfolio, maintain a central register recording the address, responsible person, cooling capacity, report reference number, inspection date and next due date for each building.

How KJ Tait Can Help

KJ Tait provides TM44 air conditioning inspections and initial compliance reviews for commercial buildings and property portfolios. Our accredited assessors combine the statutory inspection with practical building services engineering knowledge, helping clients understand both their compliance position and the opportunities to improve system operation.

If you are unsure whether a building exceeds 12kW, KJ Tait can review the available asset information, equipment schedules, F-Gas records and plant details before confirming the appropriate next step.

Frequently Asked Questions

Is a TM44 inspection a legal requirement?

Yes. In England and Wales, air conditioning systems with an effective rated output of more than 12kW must be inspected by an accredited air conditioning energy assessor at intervals not exceeding five years.

Do several small air conditioning units count towards 12kW?

Yes. Where one person controls several units in a building, their rated cooling outputs are considered together. Four 3.5kW units have a combined output of 14kW and would exceed the threshold.

Does a system rated at exactly 12kW require an inspection?

The regulations apply to systems with an effective rated output of more than 12kW. A system rated at exactly 12kW does not exceed that threshold.

How often do I need a TM44 inspection?

The interval between inspections must not exceed five years. Check the date shown on the current inspection report rather than relying on an estimated renewal year.

Can I be fined for not having a TM44 inspection?

Yes. Local weights and measures authorities enforce the requirements and can issue penalty charge notices. They can also require the responsible person to produce the relevant inspection report.

Does an F-Gas inspection count as a TM44 inspection?

No. F-Gas checks, maintenance visits and TM44 inspections have different purposes. A qualifying air conditioning system may need all of these activities.

Do I need an inspection if the air conditioning is rarely used?

Potentially, yes. The requirement is based on the effective rated output of the installed system, not simply how frequently it operates.

Who is responsible in a rented commercial building?

Responsibility depends on who controls the technical operation of the system. This may be the landlord, an occupier under the lease, a tenant that installed its own equipment or, in some circumstances, a contracted facilities management provider.

What should I do if I cannot find the previous TM44 report?

Check the building log book, operation and maintenance records and the Energy Performance of Buildings Register. If responsibility has transferred to you and no report was provided, the regulations require the system to be inspected within three months of taking control.

How do I confirm whether my building is in scope?

Prepare an asset list, verify the rated cooling output of each unit and calculate the combined output under common control. If the records are incomplete or the arrangement is unclear, ask an accredited assessor to undertake an initial compliance review.