TM44 air conditioning inspections.

One provider for TM44, EPC and ESOS.

ista can support you with TM44 inspections as well as EPCs and ESOS assessments – all in one place.

Our expert assessors help simplify compliance, reduce administrative burden and identify energy saving opportunities across your building portfolio.

Understanding statutory air-conditioning inspection requirements in the UK (2025).

TM44 inspections are mandatory energy‑efficiency assessments for air‑conditioning systems under the Energy Performance of Buildings Regulations. They apply to any building operating air‑conditioning systems with a combined cooling capacity over 12kW. These inspections must be completed by an accredited assessor every five years.

Why TM44 inspections matter.

TM44 inspections help organisations understand how efficiently their air‑conditioning systems operate and where improvements can be made. 

Air‑conditioning can account for up to 40% of a building’s energy consumption, meaning even small operational changes can deliver meaningful cost and carbon savings. The inspection identifies low‑ and no‑cost opportunities to improve performance, reduce energy use and lower emissions, while also supporting compliance with broader energy reporting frameworks such as ESOS and SECR. TM44 reports must be retained and made available to authorities upon request, with failure to comply potentially resulting in fines ranging from £300 to £800 per building.

What happens during a TM44 inspection?

A TM44 assessment typically includes:

• Review of system controls, sizing and condition
• Checks of maintenance records and operational practices
• Assessment of refrigerant type, quantity and suitability
• Identification of inefficiencies and improvement opportunities
• Practical recommendations that can deliver 10–40% energy savings in some cases

The output is a formal TM44 report outlining compliance status and recommended actions.