Is Your London Building Legally Compliant? Everything You Need to Know About TM44 Air Conditioning Inspections

If you own or manage a commercial building in London, chances are you’ll have heard about the merits of TM44 inspection, whether this be directly from a surveyor or in terms of compliance reminders and queries from landlords. For many managers of buildings, it falls into that uncomfortable category of work that seems important but never really gets to the top of the to-do list.

The problem is, TM44 compliance isn’t something you can afford to procrastinate over. It’s the law, and ignoring it is becoming a lot more serious with enforcement tightening across the capital. In this article, we will discuss exactly what TM44 inspections are, who needs them, what it entails and why you should get it sorted sooner rather than later. This makes good practical sense.

What Is a TM44 Inspection?

A TM44 inspection is a legal energy assessment of air conditioning systems fitted within commercial buildings throughout the UK. It is not a general maintenance check or service call — it is an official, government-mandated assessment conducted by a certified energy assessor.

The inspection determines the efficiency of your air conditioning system, highlights energy-wasting parts and offers a detailed report with specific recommendations. Once finished, the assessor submits a TM44 certificate to the official government register that acts as verification of your compliance. The name is derived from CIBSE’s Technical Memorandum 44, the guidance document approved for use to evaluate air conditioning energy efficiency in the UK.

Who Does It Apply To?

The rules are fairly straightforward. If the effective rated output of any air conditioning systems within your building cumulatively exceeds 12 kilowatts, a valid TM44 inspection is required by law. This includes offices, retail units, hotels, gyms, health care facilities and schools as well as most other types of commercial property.

Please note, multiple smaller units can still add up to above the 12kW limit so while you may have individual units below said limit their combined output would still count. If your combined capacity over all units is anything more than 12kW, the regulation’s for you. It is the responsibility of whoever runs that part of the air-conditioning system — be it a building owner, a landlord, a facilities manager or in some cases, a tenant who has taken on responsibility for the building’s services.

How Often Must It Be Done?

TM44 inspections must be carried out at least once every five years. Once your certificate expires, your building is immediately considered non-compliant until a new inspection is completed and registered on the government database.

Many building managers in London choose to schedule their inspections before the five-year mark, particularly ahead of lease renewals, property sales, or compliance audits, where having a current certificate on record can make a significant practical difference.

Why Does It Matter Especially in London?

London has a huge concentration of commercial floor space, and the capital has seen increasing enforcement activity in recent years. High-density business areas like Canary Wharf, The City, and Central London are under particular scrutiny.

According to recent data, more than 70% of buildings in London are overdue for inspection. One of the most common reasons is that building owners mistakenly believe their Energy Performance Certificate covers them. It does not. An EPC and a TM44 certificate are completely separate documents serving different purposes, and having one does not substitute for the other. With fines of up to £800 per site for non-compliance, and enforcement on the rise, the financial risk of ignoring TM44 requirements is real. Missing or expired certificates can also create complications during property transactions, lease renewals, and insurance renewals — situations where proof of compliance is routinely requested.

What Actually Happens During the Inspection?

A TM44 inspection is carried out by a qualified, accredited energy assessor at Level 3 or Level 4, depending on the complexity of your system. Only accredited assessors are authorised to conduct official inspections and lodge certificates on the government register.

During the visit, the assessor will carry out a thorough technical review of your air conditioning setup — examining indoor and outdoor units, reviewing maintenance records and energy logs, assessing control systems such as timers, thermostats, and zoning configurations, checking for F-Gas compliance documentation, and evaluating how well the system suits the building it serves. After the inspection, the assessor compiles the findings into a formal report that details the current condition of your system, highlights inefficiencies or problem areas, and sets out clear recommendations for improvement. The TM44 certificate is then lodged on the official government register, making it publicly verifiable. Most inspections take between one and three hours, depending on the size and complexity of the system.

It Is More Than Just a Legal Requirement

While compliance is the obvious reason to arrange a TM44 inspection, many building managers find the results genuinely useful beyond avoiding a fine.

Air conditioning systems that have not been assessed in several years can quietly waste considerable amounts of energy. Poorly calibrated controls, outdated settings, and inefficient operation all add up — and in a city like London where operating costs are already high, that waste has a direct cost attached to it. Acting on the recommendations in a TM44 report can reduce cooling costs noticeably and extend the working life of your equipment, which in turn reduces maintenance and replacement expenses over time.

TM44 vs EPC vs F-Gas: Understanding the Difference

There is often confusion between TM44 inspections and other compliance certificates, so it helps to understand what each one covers.

A TM44 certificate assesses the energy efficiency and performance of your air conditioning system and is valid for five years. An EPC rates the overall energy performance of the building itself and is valid for ten years. An F-Gas check involves testing for refrigerant leaks from your cooling systems and is typically required every six to twelve months depending on system size. All three serve different regulatory purposes, and if your building has air conditioning, it is likely that you need all three at different intervals to remain fully compliant.

How to Check If Your Building Is Compliant

You can check whether your building has a valid TM44 certificate by searching the official GOV.UK TM44 register using your postcode, address, or certificate number. If your property does not appear, or if the certificate has expired, you will need to arrange a new inspection.

Checking this proactively is far better than waiting to be asked. Auditors, insurers, landlords, and prospective tenants can all look up your compliance status directly on the public register, so an expired or missing certificate is not something that stays hidden for long.

Staying on the Right Side of the Rules

TM44 inspections apply to a very large number of commercial buildings across London, and the rules around them are not going away. If anything, enforcement is becoming more consistent and the financial penalties for non-compliance are increasing.

The process itself is far less complicated than many building managers expect. An accredited assessor visits your site, carries out the inspection, and lodges the certificate — usually within a matter of days. What you get in return is not just legal cover, but a clearer picture of how your air conditioning system is performing and where money might be leaving through inefficiency. If you are unsure whether your building qualifies or when your last inspection was carried out, a quick search on the government’s TM44 register is the most sensible place to start.