What Is a TM44 Air Conditioning Inspection?
Last updated: 2 November 2026
A TM44 inspection is a statutory energy assessment of a building's air conditioning system, carried out by a CIBSE-accredited assessor to check efficiency and compliance. The requirement has applied since 2011 under UK energy legislation, per SOCOTEC UK (2025), and applies to systems with a combined effective rated output above 12kW.
Commercial landlords and facilities managers in London and across the UK must treat TM44 as a recurring compliance obligation, not a one-off task. Every qualifying system requires a valid TM44 report, reassessed every five years, according to CCA Environmental Ltd, citing GOV.UK (2025). Non-compliance carries fixed-penalty notices of up to £300 per system, as confirmed by Chillmasters Services Ltd (2026).
Key Takeaways
- A TM44 inspection is the legal energy assessment required for air conditioning systems above 12kW, mandatory since 2011 per SOCOTEC UK (2025).
- TM44 reports must be renewed every five years for systems over 12kW, per CCA Environmental Ltd, citing GOV.UK (2025).
- Non-compliance can trigger fines of up to £300 per unit, with further penalties for continued breach, per SEA Consulting (2025).
- Reports must be lodged on the government's national register, and missing systems attract fixed-penalty notices of up to £300 each, per Chillmasters Services Ltd (2026).
What a TM44 inspection means in practice
A building owner or managing agent responsible for a commercial property must identify every air conditioning system on site and establish whether its combined output exceeds 12kW. For systems first commissioned on or after 1 January 2008, the first inspection deadline fell within five years of that date, while larger systems over 250kW faced an earlier deadline of 4 January 2009, and all qualifying systems needed inspection by 4 January 2011, per CCA Environmental Ltd, citing GOV.UK (2025). A CIBSE-registered assessor then inspects refrigerant levels, controls and overall efficiency, producing a report lodged on the national register. Priority First manages this compliance obligation as part of its wider Facilities Management service for commercial and residential buildings across London.
Related terms
- CIBSE — the Chartered Institution of Building Services Engineers, the body that accredits TM44 assessors.
- EPBD — the Energy Performance of Buildings Directive, the EU legislation that originally introduced mandatory air conditioning inspections, retained in UK law.
- F-Gas Regulations — separate rules governing refrigerant handling that often run alongside TM44 compliance checks.
- Effective rated output — the combined cooling capacity of a building's air conditioning units, measured in kilowatts, used to determine whether TM44 applies.
- Non-Domestic EPC register — the government database where TM44 reports and energy performance certificates are lodged.
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- Office Facilities Management London | Priority First 2026
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