If you are responsible for a commercial building with air conditioning, the term TM44 is likely to appear on your compliance checklist. TM44 inspections are a legal requirement for many air conditioning systems, and getting the timing right is essential. Miss the deadline and your building falls out of step with UK energy efficiency regulations. This article explains how often you need a TM44 inspection, when the five-year period starts and what can trigger a fresh assessment.
What Is a TM44 Inspection?
A TM44 inspection is a professional and comprehensive assessment of an air conditioning system. It is sometimes referred to as a TM44 survey, and it is carried out by an accredited energy assessor. The inspection evaluates the energy performance of the system and considers whether the equipment is appropriately sized for the cooling load of the building. It also identifies opportunities to improve operational efficiency and reduce running costs.
The legal basis for the inspection sits in the Energy Performance of Buildings (Certificates and Inspections) Regulations 2007, which were followed by the Energy Performance of Buildings (England and Wales) Regulations 2012 and updated again in 2020. These regulations implement the EU Energy Performance of Buildings Directive, and TM44 inspections remain a mandatory part of compliance. The inspection report provides a clear record of the system’s condition, efficiency and any recommendations for improvement.
How Often Is a TM44 Inspection Required?
The simple answer is every five years. A TM44 inspection is a compulsory requirement that must be conducted within a maximum interval of five years since the last inspection. The regulations require that inspections are no more than five years apart, and systems with an output of more than 12kW should be inspected at least every five years.
This five-year frequency applies to the ongoing cycle of certification. Once you have an inspection, your next one is due within five years from the date on your certificate. It is not calculated from the date the system was installed, commissioned or first used. Keeping track of the certificate date is therefore the most reliable way to manage your compliance calendar.
When Does the Five-Year Period Start?
The five-year TM44 inspection frequency period starts from the date on your certificate, not from installation, commissioning or first use. This is an important distinction. Many building owners assume the clock begins when the air conditioning system was installed, but the regulations are clear that the certificate date is the reference point.
To find your re-inspection deadline, check the date on your most recent TM44 certificate and count forward five years. Keep the certificate in your compliance file and set a reminder ahead of the expiry date. If you have any doubt about the certificate date, an accredited assessor can help you confirm what is recorded.
First Inspections for Systems Installed After December 2008
For air conditioning systems installed on or after 30 December 2008, the first inspection must take place within five years of the installation date. This rule applies where the system is otherwise within the scope of the regulations.
After the first inspection, the standard five-year cycle applies from the certificate date. The GOV.UK guidance on air conditioning inspections in buildings confirms that inspections must be no more than five years apart. If you are unsure whether your system has been inspected before, an accredited assessor can check the details and confirm what you need to do.
Which Systems Are Covered by the 12kW Threshold?
The regulations apply to air conditioning systems with a rated output exceeding 12kW. If the air conditioning systems in your building collectively exceed 12kW in output, you are legally required to arrange a TM44 inspection at the required intervals.
This threshold covers many commercial buildings with comfort cooling, including offices and retail premises. A single system with a lower output may fall outside the requirement, but the combined output of all the air conditioning systems in a building must be considered before assuming an inspection is not needed.
If you are uncertain whether your building is within scope, the safest approach is to ask an accredited assessor to review the system details. They can confirm whether a TM44 inspection is required and help you schedule it at the right time.
Who Is Responsible for Arranging the Inspection?
According to the regulations, if you control a refrigerant air conditioning system with a rated output exceeding 12kW, it is mandatory for you to organise a TM44 inspection at the specified intervals. The official guidance identifies the relevant person in the building as the party who must arrange the inspection.
This responsibility usually falls to the building owner or the person with day-to-day control of the system. The important point is that someone with control of the system must take ownership of the inspection cycle. If you are unsure who holds that responsibility in your building, confirm it before the certificate expires.
What If Your System Is Modified or Replaced?
A TM44 inspection is not only triggered by the passage of time. If your air conditioning system is modified or replaced, a new inspection may be required. This means significant changes to the system can reset the inspection clock or demand a fresh assessment before the usual five-year date arrives.
The guidance also notes that new controllers have three months to arrange the inspection. If you install new control equipment, you should treat this as a prompt to bring the updated system into compliance without delay. Always check with an accredited assessor if you are planning modifications, so you know exactly what the regulations require for your situation.
Why the Five-Year Cycle Matters
Regular TM44 inspections are not just an administrative exercise. They help you achieve better operational efficiency from your air conditioning system and keep you legally compliant with the UK regulations that implement the Energy Performance of Buildings Directive.
There is also a strong financial case for keeping inspections up to date. The guidance for TM44 inspections points to potential reductions in cooling energy use of up to 40% as a result of improvements identified during the inspection. For a large commercial building, that level of saving can have a significant impact on running costs and carbon emissions.
Compliance matters for practical reasons too. Tenants, buyers and lenders increasingly ask for up-to-date building compliance documentation. A valid TM44 certificate demonstrates that the building is being managed responsibly and can smooth the path when you come to sell, let or refinance.
Practical Tips for Staying Compliant
Many businesses align their TM44 inspections with their maintenance cycle. Because air conditioning systems are usually serviced on a regular schedule, linking the inspection to an existing maintenance visit can make compliance easier to manage and reduces the risk of missing the deadline.
- Check the date on your current TM44 certificate and note the five-year deadline
- Set a reminder well before the expiry date so you can book an accredited assessor
- Keep your inspection records alongside other building compliance documents
- Ask your maintenance contractor whether an inspection is due if you are unsure
- Review the certificate after any significant change to the system
Booking the inspection a little early is generally better than leaving it to the last minute. The assessor will need access to the system and to relevant building documentation, and even a short delay can push you past the deadline. A proactive approach keeps you compliant, protects your operational efficiency and gives you peace of mind.
Frequently Asked Questions
These are the questions building owners and facilities managers most often ask about TM44 inspection timing and compliance.
Is a TM44 inspection a legal requirement?
Yes. TM44 inspections are compulsory for air conditioning systems with an output exceeding 12kW. The requirement is set out in UK energy performance regulations, which implement the EU Energy Performance of Buildings Directive. If you are the person responsible for the system, you must arrange an inspection at the required intervals and keep the resulting certificate as evidence of compliance.
How long is a TM44 inspection valid?
A TM44 inspection certificate is valid for five years. The next inspection must take place no more than five years after the date on the previous certificate. You should count the period from the certificate date, not from the date the system was installed or the inspection was booked.
What happens if I miss the five-year deadline?
If you miss the deadline, you are not complying with the regulations. You should arrange a new inspection as soon as possible and bring your certificate up to date without further delay. Aligning future inspections with your maintenance cycle is one way to avoid the same problem, and an accredited assessor can advise on your specific circumstances.
Do I need a new TM44 inspection if I change my air conditioning system?
If the system is modified or replaced, a new inspection may be required. Significant changes can reset the inspection clock, so you should arrange an assessment of the updated system. Where new controllers are installed, the guidance indicates that you have three months to arrange the inspection. Ask an accredited assessor to confirm what applies to your system.
