Air conditioning legislation and compliance

Who can work on air conditioning

Most air conditioning and heat pump systems use a fluorinated greenhouse gas, or F gas, as their refrigerant. In Great Britain, any company working on equipment containing F gas, including sole traders, must be certified by an approved body. GOV.UK explains this in its guidance on certification for companies working on equipment containing F gas. The engineers doing the work need their own F-gas qualifications as well.

Great Britain keeps the retained version of Regulation (EU) 517/2014. Northern Ireland follows the EU’s newer F-gas rules, so the details there differ. AirCon Doctor is an F-Gas certified company, and our certification details are available on request.

Leak checks and records

The duty to check for leaks depends on how much refrigerant a system holds, measured in tonnes of CO2 equivalent (tCO2e). To work it out, multiply the refrigerant charge in kilograms by its global warming potential (GWP) and divide by 1,000. So 3 kg of R32 (GWP 675) is about 2.0 tCO2e, and 3 kg of R410A (GWP 2088) is about 6.3 tCO2e. The GWP figures come from the annex to Regulation 517/2014.

GOV.UK’s leak checking guidance sets the intervals:

• 5 to less than 50 tCO2e: at least every 12 months.
• 50 to less than 500 tCO2e: at least every 6 months.
• 500 tCO2e or more: automatic leak detection is required, and it must itself be checked, every year for most equipment.

Fitting a leak detection system lets you double the checking interval. Hermetically sealed systems have no maximum period unless they hold 10 tCO2e or more. Responsibility is shared between the equipment’s operator, usually the owner or the business that runs it, and the technicians who service it. Keep records of every check, top-up and repair. Many small domestic splits fall below 5 tCO2e, but multi-split and VRF systems often don’t. Our maintenance contracts cover the checks and records for businesses.

Bans on new equipment

Some F gases can no longer be used in new products. GOV.UK lists the current and future bans. Two matter most for air conditioning:

• Movable (portable) air conditioning using HFCs with a GWP above 150 is banned.
• From 2025, new single split systems holding less than 3 kg of refrigerant can’t use F gases with a GWP above 750. There are exceptions, including larger splits and air-to-water single splits.

That is why most new small split systems now use R32, which has a GWP of 675. Our guide to R32 and R410A explains the difference.

The HFC phase-down and 2027

Separately from the bans, the amount of HFC refrigerant that can be placed on the market in Great Britain is capped and steps down over time. The government consulted on changing the schedule, and on 15 May 2026 it confirmed it will not legislate in 2026 to change the steps from 1 January 2027. That means the existing step applies, taking the GB quota down to 24% of the baseline from 1 January 2027.

In practice, supply gets tighter. Higher-GWP refrigerants such as R410A are likely to become scarcer and dearer to buy for top-ups. Repairing and servicing existing R410A systems remains legal. R22 is different: it is an ozone-depleting HCFC, and the rules on ozone-depleting substances allowed reclaimed HCFCs to be used for servicing only until 31 December 2014, so R22 systems can no longer be topped up. Our guides to the 2027 phase-down and repairing or replacing older systems go further.

Planning permission

In England, an air source heat pump on a house can be permitted development, meaning no planning application is needed, if it meets the conditions on the Planning Portal. In summary:

• The outdoor unit, with its housing, is no more than 1.5 m³.
• It complies with MCS 020(a), which includes a noise check. From 28 May 2026 MCS 020(a) is the only permitted scheme.
• It is not used solely for cooling.
• It is not within the curtilage of a listed building or on a scheduled monument.
• In conservation areas and World Heritage Sites, it is not on a wall or roof facing a highway, or nearer a highway than the house. Elsewhere, it is not on a wall above ground floor facing a highway.
• It is not on a pitched roof, and on a flat roof it is at least 1 m from the edge.
• Detached houses may have two units; other houses one.

Flats and blocks of flats have different limits, including a 0.6 m³ size limit. Councils can remove these rights with an Article 4 direction. Since 2025 the rights also cover air-to-air heat pumps, but a cooling-only air conditioning unit is not covered, so check with your council. Listed building consent is a separate matter. Our guide to planning permission for air conditioning has more detail.

Electrical work and Part P

Electrical work in homes in England must meet Part P of the Building Regulations. The Planning Portal lists “the installation of a complete new circuit” as notifiable work, and most air conditioning needs a dedicated circuit. An installer registered with a competent person scheme can self-certify the work. Otherwise, building control must be told before work starts, and the work inspected. We’re NICEIC approved, so we certify the circuit ourselves. See our guide to new circuits and Part P.

TM44 air conditioning inspections

Under the Energy Performance of Buildings Regulations, buildings with air conditioning systems of more than 12 kW effective rated output need an energy inspection, no more than five years apart, by an accredited energy assessor. Separate units under 12 kW count if their combined output is more than 12 kW and one person controls them. The report must be lodged on the national register. GOV.UK’s guide to air conditioning inspections sets out penalties of £300 for not having a report and £200 for not providing it to Trading Standards within seven days. The inspection method is CIBSE’s TM44. We’re not energy assessors, but we can arrange or prepare for a TM44 inspection and fix what it finds.

Grants and VAT

The Boiler Upgrade Scheme, set out in the 2026 regulations, gives £7,500 towards an air-to-water or ground source heat pump and £2,500 towards an air-to-air heat pump in England and Wales. The air-to-air grant needs the system to replace existing fossil-fuel heating, meet the home’s full heating demand and be fitted by an MCS certified installer; it can’t be an add-on alongside a boiler. Until March 2027, an extra £1,500 is available for air source or ground source heat pumps in homes heated by oil or LPG with no mains gas. The installer applies for the grant. See our guide to the air-to-air grant.

On VAT, HMRC’s Notice 708/6 zero-rates installing energy-saving materials in homes, including permanently fixed air source heat pumps, until 31 March 2027, then 5%. HMRC says most air conditioning units are air source heat pumps, but each case depends on its facts. Businesses pay the standard rate. We confirm the VAT on your quote; our guide to zero VAT explains more.

This page is general information, not legal or tax advice. For advice on your situation, speak to your council, HMRC or a qualified adviser. Questions about your system? Call 07833 053749.

General information, checked against the official sources linked on 30 October 2026. It isn’t legal advice.