Air conditioning quietly runs up some of the largest energy bills in any commercial building. A TM44 inspection checks whether that system is working as it should, and whether it meets the legal standard set for cooling equipment across England and Wales. Skip it, and the risk builds slowly, until an enforcement officer or a property buyer asks to see the paperwork.
Knowing how often you need a TM44 air conditioning inspection puts you in control of your compliance calendar and helps you plan the cost well ahead of any deadline. A provider such as TM44.uk can confirm your schedule, though the basic rule is simple enough to check yourself. This guide covers when it is due, what happens on the day, and how to get ready.
What Is a TM44 Air Conditioning Inspection?
A TM44 inspection is an energy assessment of a building’s air conditioning, carried out by an accredited assessor. The name comes from CIBSE Technical Memorandum 44, the guidance assessors follow. It sits under the Energy Performance of Buildings Regulations, so for many businesses it is a legal duty rather than a nice-to-have.
The duty applies to systems with an effective rated output above 12kW. That figure catches more buildings than people expect. Four wall-mounted units at 3.5kW each already pass the threshold once they sit under one person’s control. Offices, shops, clinics, warehouses and schools all tend to qualify, whatever the size of any single unit.
The point of it is partly compliance and partly money. A good report shows where cooling is wasted through poor controls, bad scheduling or worn-out equipment. Acting on those findings can cut running costs and keep the system healthier for longer.
How Often Is a TM44 Inspection Required?
The core rule is short. A qualifying air conditioning system must be inspected at least once every five years, and the certificate produced stays valid for exactly that period. Once five years pass from the date of the last inspection, the certificate lapses and the building falls out of compliance, even if the equipment still runs fine.
The clock runs from the inspection date, not the day the system was installed. Buy a building with existing air conditioning and you inherit the previous owner’s deadline. Miss it, and the gap becomes your problem, not theirs. Many assessors suggest booking the first inspection within three years of a new system going live, to build in breathing room.
Sometimes an earlier visit makes sense. Big changes to the system, added units, a major refit, or a run of high bills and comfort complaints are all reasons to bring the date forward. An inspection after significant work gives you a fresh baseline and flags any new problems before they settle in.
What Happens During a TM44 Inspection?
A TM44 inspection is visual and non-invasive, so nothing gets dismantled. The assessor reviews the refrigeration equipment, the fans and air handling, and the controls that decide when cooling runs. They also check maintenance records and how the system is used from day to day. Clear access to units and plant rooms keeps the visit short.
Two accreditation levels exist. Level 3 covers simpler split and VRF systems, while Level 4 handles complex centralised plant. Meeting the air conditioning inspection requirements means using an assessor qualified for your type of system. This is where a proper commercial air conditioning inspection differs from a routine service call, since the focus is energy performance and compliance, not repairs.
Afterwards you receive a report and a certificate lodged on the national Landmark Register. The report is an energy efficiency inspection at heart. It lists where the system wastes power and offers practical fixes, from adjusting timers to correcting set points. You are not legally forced to act on the advice, though ignoring it usually costs money.
Why Staying Up to Date with TM44 Inspections Matters
Letting a certificate expire rarely feels urgent until it suddenly does. Staying current under the TM44 regulations protects the business on several fronts at once, and most of them hit the bottom line. Here is what keeping up to date buys you.
- Legal protection: local authorities can issue a fixed penalty of £300 for each system without a valid report. Gaps most often surface during property sales and lease negotiations, and a missing certificate can stall a deal at the worst possible moment.
- Lower bills. A poorly run system can burn through far more energy than it needs to. The report tells you exactly where.
- Kit that lasts: a system that is correctly controlled and maintained tends to run for longer before it needs replacing, which spreads out capital spend.
- A smaller carbon footprint, which increasingly matters for ESG reporting, MEES obligations and tenant expectations.
Framed this way, TM44 compliance stops looking like a box to tick. It becomes a cheap way to protect an asset and keep a building lettable, without the awkward conversation with an enforcement officer or a buyer’s solicitor.
How to Prepare for Your Next TM44 Inspection
A little preparation makes the visit faster and the report more useful. Pull together your maintenance records and any documentation on the system, since gaps in paperwork slow the assessor down. Make sure units, ceiling voids and plant rooms can be reached without hunting for keys on the day.
Timing matters too. Check when your current certificate expires and book well before that date, rather than scrambling once you are already non-compliant. Portfolio managers often keep a simple spreadsheet of every site and its expiry, with reminders set a few months ahead, so nothing slips past.
Above all, use an accredited assessor qualified for your system type. An unaccredited report will not lodge on the register and will not count. It is a small check that saves a repeat visit and a second bill later on.
Getting Ahead of the Deadline
The five-year cycle sounds like plenty of time until the fifth year arrives and the diary is full. Treating the inspection as a planned event, booked early and slotted into a wider maintenance routine, takes the pressure off and usually produces a better outcome than a rushed visit under deadline stress.
Check your expiry date this week. If it is close, or if you are not sure when your last inspection happened, that uncertainty is the real risk. A quick call to an accredited assessor settles it, and turns a vague worry into a date in the calendar.
Frequently Asked Questions
How often do I legally need a TM44 inspection?
At least once every five years for any qualifying system. The certificate is valid for five years from the inspection date, and you become non-compliant the moment it expires, whatever condition the equipment is in.
Which air conditioning systems require a TM44 inspection?
Any system with an effective rated output above 12kW. That total combines every unit under one person’s control, so several small units in one building often qualify even when no single unit reaches the threshold.
What happens if my TM44 inspection has expired?
The building is non-compliant, and local authorities can issue a fixed penalty of £300 for each affected system. Expired or missing reports also tend to cause delays during property sales and lease transactions.
How long does a TM44 inspection usually take?
It depends on the size and complexity of the system. A single simple installation might take a couple of hours, while a large centralised plant across several floors takes considerably longer. Good access speeds things up.
Does a TM44 inspection replace regular air conditioning maintenance?
No. The inspection is an energy assessment, not a service. It sits alongside routine maintenance and does not clean, repair or replace anything. You still need a servicing schedule to keep the system running well.
