What is a TM44 Inspection and Why Does Your Business Need One?

A TM44 inspection is a legally required energy assessment of any commercial air conditioning system with a combined rated output above 12kW, carried out every five years by an accredited assessor. Despite this being a statutory obligation under the Energy Performance of Buildings (England and Wales) Regulations 2012, many business owners, landlords and facilities managers across the North East remain unaware of the requirement — or uncertain about what the process actually involves. This comprehensive guide explains everything you need to know about TM44 air conditioning inspections: the legal basis, what happens on site, who the requirement applies to, and why it pays to act sooner rather than later.

What Is a TM44 Inspection? Understanding the Legal Requirement

Something we get asked a lot at AirCert is “What is a TM44 inspection”? The term TM44 refers to Technical Memorandum 44, a guidance document published by the Chartered Institution of Building Services Engineers (CIBSE). It sets out the methodology that accredited energy assessors must follow when inspecting air conditioning systems in commercial and public buildings. The legal requirement originates from the Energy Performance of Buildings (England and Wales) Regulations 2012, which transposed the EU Energy Performance of Buildings Directive into UK law. Following Brexit, these requirements remain firmly in force as part of retained UK legislation.

Because we often get asked “what is a TM44 inspection”? we know that it isn’t something that a lot of people are familiar with. A TM44 inspection is not a service or maintenance check. It is an independent energy assessment of your air conditioning system, designed to evaluate how efficiently the system operates and to identify opportunities for reducing energy consumption. Upon completion, the assessor issues a formal TM44 certificate — sometimes called an Air Conditioning Inspection Report — which is lodged on the national Landmark register and must be made available to local authority enforcement officers on request. Because all TM44 certificates are registered nationally, enforcement officers can directly identify buildings that should hold a certificate but do not — making non-compliance far more detectable than many building managers assume.

What is a TM44 Inspection Professional Actually Going to Look For?

A qualified, accredited energy assessor will attend your premises and carry out a thorough review of your air conditioning system. A typical TM44 inspection covers the following areas:

What is a TM44 Inspection Actually Going To Do For My Business?

While it is not a hugely well-known certification, it is iegally-mandated that all AC systems over 12kW are inspected at least every 5 years. Getting an AirCert TM44 inspection ensures that your organisation stays within the law.

• System identification and sizing: The assessor records the type, age, capacity and configuration of all air conditioning units and associated components — including split systems, multi-split systems, VRF/VRV systems, chillers, fan coil units and packaged rooftop units.
• Assessment of system controls: The inspection evaluates whether appropriate controls are in place — timers, thermostats, zone controls and building management systems (BMS). Poorly configured or absent controls are among the most common sources of avoidable energy waste in commercial buildings.
• Refrigerant and condition checks: While the assessor does not carry out F-Gas testing, they will note the refrigerant type and assess the general condition of the equipment, including visible signs of leaks, poor maintenance or deterioration.
• Building fabric and heat gains: The assessor considers the building itself — orientation, glazing, insulation and internal heat sources — to assess whether the cooling demand is proportionate and whether the system is working harder than necessary.
• Comparison against benchmarks: The system’s performance is compared against recognised efficiency benchmarks to identify shortfalls and prioritise improvements.
• Recommendations report: The final TM44 certificate includes a prioritised list of recommendations for improving the energy efficiency of the system and reducing running costs — in plain, actionable language.

A straightforward TM44 inspection for a single system in a standard office or retail unit can typically be completed within two to three hours. Larger or more complex installations — multi-zone VRF/VRV networks, chilled water plant, or multi-tenanted buildings — will take longer and require a Level 4 accredited assessor.

Who Needs a TM44 Inspection?

The legal threshold is clear: any air conditioning system with a combined effective rated output exceeding 12kW requires a valid TM44 inspection certificate. This threshold catches many building owners off guard — it does not require a large centralised cooling installation. A building with just two or three wall-mounted split units can comfortably exceed 12kW when their outputs are totalled. The obligation applies across a wide range of premises, including (but not limited to):

• Offices and business parks
• Retail units and shopping centres
• Hotels, restaurants and leisure facilities
• Healthcare facilities, GP surgeries and dental practices
• Warehouses and industrial units with conditioned spaces
• Schools, colleges, universities and care homes
• Server rooms and data centres
• Mixed-use buildings with commercial air conditioning

If you are a commercial landlord, the responsibility for arranging the TM44 inspection typically sits with you — although the terms of the lease may transfer compliance obligations to the occupier. Building and facilities managers should confirm whether a valid certificate is in place and ensure it is renewed before expiry. There is no grace period for a lapsed certificate: from the moment it expires, the building is non-compliant and exposed to enforcement action.

Why Your Business Needs a TM44 Inspection

Legal Compliance and Enforcement

The most immediate reason to arrange a TM44 inspection is straightforward: it is the law. Local authority Trading Standards departments have the power to issue penalty charge notices to building owners or occupiers without a valid air conditioning inspection certificate. The current fine for non-compliance is £300 for systems between 12kW and 250kW — and it can be issued repeatedly until a valid certificate is produced. Enforcement across the North East and Yorkshire is increasing, particularly during EPC-related inspections and commercial property transactions, where a missing TM44 certificate can delay or derail a sale or letting.

Energy Savings and Reduced Running Costs

Beyond compliance, a TM44 inspection delivers genuine commercial value. Air conditioning systems are among the largest consumers of electricity in commercial buildings, typically accounting for 20–35% of total energy expenditure. Over time, systems lose efficiency through component degradation, poor maintenance, refrigerant losses and incorrect settings. Independent data indicates that acting on a TM44 report’s recommendations can reduce a system’s running costs by 15–25% — savings that, for a typical commercial office building running air conditioning for 2,500 hours per year at current electricity rates, often amount to several hundred pounds annually and pay back the cost of the inspection within the first year. Common findings include oversized systems running at partial load, conflicting heating and cooling cycles, inadequate zoning, and thermostat settings far lower than operationally necessary.

Supporting Your Net Zero and ESG Commitments

Many businesses in the North East are working towards carbon reduction targets, driven by corporate social responsibility commitments, ESG reporting obligations or the UK’s wider net zero agenda. A TM44 inspection provides a clear, evidence-based assessment of your cooling system’s energy performance and a practical roadmap for improvement. Implementing the report’s recommendations demonstrates measurable progress in reducing your building’s operational carbon emissions — increasingly expected by insurers, investors and major contract clients.

Protecting Property Value and Lease Obligations

For commercial landlords, maintaining a valid TM44 certificate is increasingly important during property sales, lettings and refinancing. Solicitors acting for prospective tenants and buyers now routinely request evidence of TM44 compliance as standard conveyancing due diligence — in the same way that EPCs have become non-negotiable in commercial transactions. A missing or expired certificate can delay completions, reduce the perceived management quality of the asset, and in some cases give tenants grounds to renegotiate lease terms.

Choosing the Right TM44 Inspector

Not all energy assessors are qualified to carry out TM44 inspections. The assessor must hold a valid Level 3 or Level 4 air conditioning inspection qualification accredited by an approved certification scheme. The level required depends on the complexity of the system:

• Level 3 accreditation covers simpler systems — single split, multi-split and packaged units commonly found in offices, retail premises and smaller commercial buildings.
• Level 4 accreditation covers complex systems, including centralised chiller plant, VRF/VRV networks, air handling units with cooling coils and building-wide systems integrated with a BMS.

At AirCert, we hold both Elmhurst Level 3 and Level 4 accreditation, meaning we are fully qualified to inspect the complete range of air conditioning systems — from a single wall-mounted unit in a small office to complex centralised cooling installations in large commercial buildings. Elmhurst Energy is one of the UK’s leading government-approved accreditation bodies, and our registration ensures every TM44 certificate we issue is lodged on the official Landmark register and fully compliant with current legislation.

What to Expect When You Book with AirCert

We aim to make the TM44 inspection process as straightforward as possible for our clients across the North East of England and Yorkshire. Here is what the process looks like from first contact to certificate delivery:

• Quick, transparent quotation: Tell us about your building and your air conditioning system, and we will provide a clear, fixed-price quote with no hidden charges. Request your quote here.
• Flexible scheduling: We minimise disruption to your operations by arranging inspection visits at times that suit you, including outside normal business hours where needed.
• Thorough, professional inspection: Our accredited assessors carry out a comprehensive assessment in line with the CIBSE TM44 methodology, examining every relevant component of your system.
• Fast certificate turnaround: Your TM44 certificate and recommendations report are typically issued within a few working days of the inspection, lodged on the Landmark register and sent directly to you.
• Expert follow-up advice: If you have questions about your report or want to discuss how to act on the recommendations, we are always happy to provide further guidance.

Common Questions About TM44 Inspections

How Often Do I Need a TM44 Inspection?

A TM44 certificate is valid for five years from the date of the inspection. You must arrange a new inspection before the existing certificate expires to maintain continuous compliance. We recommend booking your renewal at least four to six weeks before the expiry date to avoid any gap in coverage.

Is a TM44 Inspection the Same as an Air Conditioning Service?

No. A TM44 inspection is an independent energy assessment, not a maintenance or servicing visit. Regular servicing by an F-Gas registered engineer is essential for system reliability and regulatory compliance under F-Gas Regulations — but it does not fulfil the separate legal requirement for a TM44 inspection. Both are required, and many clients choose to coordinate the two on the same day to minimise disruption to their building.

What Happens If I Do Not Have a Valid Certificate?

You risk a penalty charge notice from your local Trading Standards authority. You may also encounter complications during commercial property transactions, lease negotiations and insurance renewals. Beyond the legal risk, operating without an up-to-date TM44 inspection means you are likely missing opportunities to reduce energy waste and cut operating costs.

Does the 12kW Threshold Apply Per Unit or Per Building?

The threshold applies to the combined effective rated output of all air conditioning systems serving a building. Individual units may each be below 12kW, but if their combined output exceeds this figure, a TM44 inspection is required. This catches many building owners out — particularly in offices and retail units with several modest-sized split units installed across different rooms or floors.

Take Action Today

If you own, manage or occupy a commercial building in the North East of England or Yorkshire with air conditioning, checking your TM44 compliance should be a priority. Whether you need a first inspection or a renewal, AirCert provides a professional, fully accredited service that ensures you meet your legal obligations while identifying real opportunities to improve energy efficiency and reduce costs.

Ready to book your TM44 air conditioning inspection? Get a quote from AirCert today and ensure your business is fully compliant with current regulations.