Do I Need a TM44 Inspection? The 12kW Rule Explained
## The TM44 Inspection: Who Needs One?
The TM44 air conditioning inspection requirement catches many building owners and tenants by surprise. Unlike some other compliance obligations, there is no notification system — it's your responsibility to know whether your building is in scope and to arrange an inspection proactively.
### The Core Rule: 12kW Combined Output
You need a TM44 inspection if the **effective rated output** of your building's air conditioning systems exceeds **12kW in total**.
The critical word is "total". You don't need a single large system — the regulation aggregates all AC units in the building. Examples:
- **2 × 7kW split units = 14kW combined → TM44 required**
- **4 × 3.5kW cassette units = 14kW combined → TM44 required**
- **1 × 10kW single unit = 10kW → TM44 NOT required**
- **3 × 5kW ceiling cassettes = 15kW combined → TM44 required**
### What Counts as "Air Conditioning"?
For TM44 purposes, "air conditioning" means any system that provides cooling — not just systems with the words "air conditioning" in the product name. This includes:
- Split and multi-split systems
- VRF and VRV systems
- Cassette air conditioning units
- Fan coil units connected to a chiller
- Close-control units and precision cooling
- Portable air conditioning units (if permanently installed)
Systems used **only for heating** (including heat pumps in heating-only mode) are generally excluded. Reversible heat pumps with a cooling function may be in scope — ask your assessor.
### What Doesn't Count?
- Mechanical ventilation without cooling
- Fans and evaporative coolers
- Refrigeration systems for food storage
- Data centre cooling where the space is not for human occupancy
### How to Check Your Building
1. Find the specification plate on each AC unit (usually on the side of the outdoor condenser unit)
2. Note the "Cooling Capacity" in kW for each unit
3. Add the figures together
4. If the total exceeds 12kW, you need a TM44
If you're unsure, contact Avorria for a free pre-inspection consultation. We can confirm your compliance status over the phone before you commit to a booking.
### What Happens If I Don't Have One?
Trading Standards can issue a £300 fixed penalty notice per building. An additional £200 can be charged for failing to produce the report within 7 days. These fines are renewable — so ignoring the problem is significantly more expensive than getting the inspection done.
[Book your TM44 inspection online](/book?service=tm44) or [learn more about TM44](/services/tm44).
The TM44 air conditioning inspection requirement catches many building owners and tenants by surprise. Unlike some other compliance obligations, there is no notification system — it's your responsibility to know whether your building is in scope and to arrange an inspection proactively.
### The Core Rule: 12kW Combined Output
You need a TM44 inspection if the **effective rated output** of your building's air conditioning systems exceeds **12kW in total**.
The critical word is "total". You don't need a single large system — the regulation aggregates all AC units in the building. Examples:
- **2 × 7kW split units = 14kW combined → TM44 required**
- **4 × 3.5kW cassette units = 14kW combined → TM44 required**
- **1 × 10kW single unit = 10kW → TM44 NOT required**
- **3 × 5kW ceiling cassettes = 15kW combined → TM44 required**
### What Counts as "Air Conditioning"?
For TM44 purposes, "air conditioning" means any system that provides cooling — not just systems with the words "air conditioning" in the product name. This includes:
- Split and multi-split systems
- VRF and VRV systems
- Cassette air conditioning units
- Fan coil units connected to a chiller
- Close-control units and precision cooling
- Portable air conditioning units (if permanently installed)
Systems used **only for heating** (including heat pumps in heating-only mode) are generally excluded. Reversible heat pumps with a cooling function may be in scope — ask your assessor.
### What Doesn't Count?
- Mechanical ventilation without cooling
- Fans and evaporative coolers
- Refrigeration systems for food storage
- Data centre cooling where the space is not for human occupancy
### How to Check Your Building
1. Find the specification plate on each AC unit (usually on the side of the outdoor condenser unit)
2. Note the "Cooling Capacity" in kW for each unit
3. Add the figures together
4. If the total exceeds 12kW, you need a TM44
If you're unsure, contact Avorria for a free pre-inspection consultation. We can confirm your compliance status over the phone before you commit to a booking.
### What Happens If I Don't Have One?
Trading Standards can issue a £300 fixed penalty notice per building. An additional £200 can be charged for failing to produce the report within 7 days. These fines are renewable — so ignoring the problem is significantly more expensive than getting the inspection done.
[Book your TM44 inspection online](/book?service=tm44) or [learn more about TM44](/services/tm44).