TM44 Air Conditioning Inspections
If one person controls more than 12kW of air conditioning in a building, the law says it must be inspected by an accredited energy assessor at least every five years and the report lodged on the national register. Most operators only find out they are in scope when a solicitor, an insurer or an auditor asks for the report. This page is how to work out whether that is you. If you also need the system looked after rather than just inspected, the commercial page covers maintenance contracts.
General guidance, not legal advice • England & Wales • We arrange inspections through accredited assessors
What TM44 is, and what it is not
TM44 is the method. The law is the Regulations.
Everybody calls it “a TM44”, which muddles two separate things. The duty itself comes from the Energy Performance of Buildings Regulations. TM44 is the technical memorandum published by CIBSE that tells an assessor how to carry the inspection out: what to look at, what to measure, how to write it up.
So when a managing agent asks for “your TM44”, what they actually want is the air conditioning inspection report lodged against the building under those Regulations. The memorandum is the recipe; the Regulations are the reason you have to cook.
It is an energy inspection, not a service visit
An assessor does not clean a filter, weigh in refrigerant or fix a fault. They look at the plant, the controls, the paperwork and the way the system is actually being used, then form a judgement: is it the right size for the building, is it being maintained well enough, and where is energy going to waste? The output is a report with recommendations.
Acting on those recommendations is voluntary. Holding the report is not. And because it is a different duty with a different qualification behind it, having a maintenance contract does not discharge it, any more than an MOT covers a service.
Are you in scope? The 12kW question
The threshold is 12kW of effective rated output, and this is the part almost everybody gets wrong. It is not measured per unit. Where several systems sit under the control of one person in one building, their outputs are added together, so a shop with four modest wall units can be in scope while not one of those units is anywhere near 12kW on its own.
Not one unit is close to 12 kW on its own. Together they are over the line, and the building is in scope.
| If this is your building | Then |
|---|---|
| One 7kW split serving a small office, and nothing else | Out of scope. Under 12kW combined, so no inspection duty arises. |
| Four 3.5kW wall units in a retail unit | In scope: 14kW combined. This is the case that catches people. Each unit looks far too small to matter, and together they are over the line. |
| Three 5kW cassettes in an open-plan office | In scope: 15kW combined. Same arithmetic, different format of unit. |
| A single VRF system serving a whole building | In scope, comfortably. Most VRF condensers clear 12kW on their own, and the inspection covers the indoor units and controls as well as the outdoor plant. |
| Two tenants in one building, each with their own system | The duty follows the person who controls the system, not the building. Each tenant is assessed on what they control. Whether that is you or your landlord depends on your lease: on a full repairing lease it is usually you. |
| Cooling provided for a process rather than for people | A cold room, or a unit dedicated to equipment rather than comfort, generally sits outside the scope of comfort cooling. The line is not always obvious, and where a system does both it is the assessor's call. |
“Effective rated output” is the manufacturer’s stated maximum output in continuous operation: the figure on the nameplate, not what the system happens to be delivering on the day. If you are close to the line, the honest answer is that you need someone to add up what is actually installed rather than what everyone remembers being installed. That is what an asset register is for, and it is the first thing we build on a survey.
When it falls due
The cycle is simple enough once you know where the clock starts. What trips people up is inheriting a building and assuming the clock started when they moved in.
The first inspection is due before the end of the fifth year from the day the system was first put into service. Not from when the building was occupied, and not from when you bought it: from commissioning.
The gap between one inspection and the next must never exceed five years. If a report is dated the 3rd of a month, the next one is due by the 3rd of that month five years on, not simply “that year”.
Whoever controlled it before you is required to hand you the most recent inspection report. Ask for it in the pack, before you complete, alongside the EPC and the refrigerant records.
You have three months from taking control to get an inspection carried out. Three months is not long once you have found an assessor, arranged access and waited for lodgement, so it is worth starting on day one rather than day sixty.
What the report actually contains
It is more useful than its reputation suggests. Whatever else it is, it is a qualified outsider spending half a day telling you the truth about plant you probably inherited.
| What the assessor looks at | Why it matters |
|---|---|
| Is it the right size for the building? | Oversized plant short-cycles, wears itself out and controls humidity badly. Undersized plant never reaches setpoint and runs flat out trying. The assessor compares installed capacity against what the building actually needs, which is frequently the most valuable line in the report. |
| The condition and efficiency of the refrigeration plant | Compressors, heat exchangers, fans and the state of the coils, assessed for how well they are converting electricity into cooling now, rather than how well they did when they were new. |
| How air actually gets to the space | Ductwork, grilles, diffusers and fans. A system can be in perfect mechanical health and still waste a third of its output because the air never arrives where the people are. |
| The controls, and how they are set | Setpoints, time schedules, zoning, and whether anything is fighting anything else. Cooling and heating running against each other in the same space is commoner than it should be and costs a fortune. |
| Whether the maintenance regime is adequate | The assessor reviews the records. A thin or absent maintenance history shows up in the report, which is one reason a system on a proper contract tends to inspect well. |
| Recommendations, and a register reference | Cost-effective improvements, and where relevant a recommendation to replace. The report carries a reference number generated when it is lodged on the Energy Performance of Buildings Register, without that number it is not a valid report. |
What happens if you have not got one
Enforcement sits with local weights and measures authorities: Trading Standards. The fines are not enormous. The timing of the problem usually is.
| If you have no valid report | What that means |
|---|---|
| £300 penalty | For failing to hold a valid current air conditioning inspection report for a system that needs one. |
| A further £200 | For failing to produce the report to an enforcement officer within seven days of being asked for it. |
| 28 days to appeal | A penalty notice can be appealed to the county court within 28 days. The duty itself does not go away while that is happening. |
| The real cost is the timing | It surfaces when a buyer’s solicitor raises enquiries, when an incoming tenant asks for the compliance file, at insurance renewal, or during an ISO 14001 audit , and an inspection cannot be backdated. You get a report from the day it is done, which is no help to a deal that needed it last week. |
Where we fit in, and where we deliberately do not
The inspection has to be carried out by an energy assessor who is a member of a government-approved accreditation scheme, and lodged on the register in their name. That independence is the point of the exercise, and we are not going to pretend otherwise. What we do is everything either side of it.
On survey we build an asset register: every indoor and outdoor unit, model, nameplate output, refrigerant type and charge, location. Adding it up is then arithmetic rather than guesswork, and you end up with a document that answers the question permanently.
Equipment records, refrigerant records, service history, commissioning data and control settings. An assessor arriving to a full file inspects faster and reports better than one arriving to a shrug.
Through an accredited assessor, with access, keys, roof permits and someone who knows where the plant is all organised in advance, which is usually the part that delays these things.
This is the half of the job that is genuinely ours. Recommendations tend to be about controls, settings, maintenance and occasionally replacement, and those are things we do. Anything we would charge you for is quoted before it happens.
Five years is exactly long enough to forget. Buildings we maintain carry the inspection date in the same schedule as the service visits and the leak checks, so it arrives as a reminder rather than as a surprise from a solicitor.
To be completely plain about it: ArcticNord do not carry out TM44 inspections ourselves. We arrange them through accredited assessors, and we do the work the report recommends. If you would rather appoint your own assessor, that is entirely normal and we will give them the records and the access they need.
Common questions
Does my maintenance contract cover the TM44 inspection?+
No, and it is worth being clear about this. A maintenance visit and a TM44 inspection are separate duties with separate qualifications behind them. Maintenance keeps the system working and keeps your F-Gas records straight; the inspection is an independent energy assessment by an accredited assessor, lodged on the national register. A good maintenance regime makes the inspection go better and usually report better, but it does not replace it.
My units are all small. Am I really in scope?+
Quite possibly. The 12kW threshold applies to the combined effective rated output of everything under one person’s control in the building, not to individual units. Four 3.5kW wall units come to 14kW, which is over the line. It is the most common way of being in scope without realising it.
Who is responsible: me or my landlord?+
The duty sits with whoever controls the operation of the system, which is not automatically the freeholder. On a full repairing and insuring lease it is usually the tenant. It can also be passed to a facilities management company by contract. If it is genuinely unclear, it is worth settling in writing, because “we each thought it was the other one” is not a defence.
How often does the inspection have to happen?+
At intervals of no more than five years. For a newly installed system the first inspection is due within five years of it first being put into service.
What if I have just taken over the building and there is no report?+
The previous person in control should have handed you the most recent report. Where none is handed over, you have three months from taking control to have an inspection carried out.
Who is allowed to carry out the inspection?+
Only an energy assessor who is a current member of a government-approved accreditation scheme, and the report has to be lodged on the Energy Performance of Buildings Register to be valid. It is not something a maintenance engineer can sign off, ourselves included.
Do I have to act on the recommendations?+
No. The recommendations are advisory. The requirement is to have the inspection done and to hold the report. That said, the recommendations are generally about controls, settings and maintenance rather than capital spend, and those tend to pay for themselves.
Does this apply in Scotland and Northern Ireland?+
The Regulations described on this page are the England and Wales ones. Scotland and Northern Ireland have their own equivalent requirements deriving from the same European directive, and the detail differs. Our own work is in the East Midlands, Lincolnshire and Yorkshire, so England is what we deal with day to day.
Not sure whether you are in scope?
The survey that answers it is free, and it is a separate visit. We are not turning up to do a service and adding it on. You get an asset register listing every unit, its output and its refrigerant charge, which settles the TM44 question and your F-Gas leak-check frequency at the same time.