Air conditioning in Britain is governed by three separate legal regimes at once, and it is easy to assume it is governed by one. The refrigerant is controlled by environmental law, the system itself is controlled building work, and the electrical circuit feeding it is controlled separately again. A business can be fully entitled to carry out one of those things and hold no authorisation at all for the other two.
What follows comes from the instruments themselves. The F-gas rules described here run across Great Britain; the building-control chain set out below is the English one, and Wales, Scotland and Northern Ireland each operate their own building-control regime. Where an outdoor unit may be sited is a separate planning question.
Three regimes, three different pieces of paper
These are not tiers of one qualification but unrelated authorisations under different instruments.
| Regime | What it controls | Instrument | Who authorises |
|---|---|---|---|
| F-gas | Work on the refrigerant circuit | Assimilated Regulation (EU) 517/2014 and Regulation (EU) 2015/2067, enforced through SI 2015/310 | Refcom Certification Ltd, F-Gas Register (Quidos), Bureau Veritas UK Ltd |
| Building Regulations – the system | Installing a fixed system in a dwelling | Building Regulations 2010, regulation 12(2) and Schedule 3 item 6 | A scheme operator registered for that Schedule 3 scope |
| Building Regulations – the electrics | The new circuit the system runs on | Building Regulations 2010, regulation 12(6A), Part P | A scheme operator registered for the Schedule 3 item 8 electrical scope |
The F-gas company certificate is a duty attached to an activity
That distinction is easy to miss. A company F-gas certificate is not a badge a firm holds in order to trade in the category — it is a duty triggered by carrying out particular acts for other people.
Article 2(2) of Regulation (EU) 2015/2067 applies to companies carrying out three categories of activity on stationary refrigeration, air conditioning and heat pump equipment for other parties: installation; repair, maintenance or servicing; and decommissioning. Article 5 requires them to hold a certificate. Government guidance puts it plainly: a company, including a sole trader, must be certified to service stationary F gas equipment operated by others, while a company servicing only its own equipment does not need to be certified.
Three approved bodies issue that certificate in Great Britain: Refcom Certification Ltd, the F-Gas Register (Quidos) and Bureau Veritas UK Ltd. It must be renewed every three years, and it is scoped rather than open-ended: Article 6(2)(b) requires it to state which activities the holder may perform and the maximum refrigerant charge size, in kilograms. Article 6(1) adds a condition on obtaining one at all — the company must employ enough certified individuals for the expected volume of work. Nor does passing work down the chain dissolve the duty: Article 10(11) of Regulation (EU) 517/2014 requires a firm assigning a certificated task to another to take reasonable steps to ascertain that it holds the necessary certificates, separately enforceable under Schedule 2 to SI 2015/310.
Engineers need their own qualification, and the charge decides the category
Company certification and personal qualification are different requirements: guidance is explicit that an individual must have their own qualifications to work on F gas equipment, even when working for someone else. The categories are defined by how much refrigerant is in the system, not by what type of system it is — so whether a split and a multi-split sit in the same category turns on the charge, not on what the system is called.
| Category | What it permits |
|---|---|
| Category I | Carry out all activities |
| Category II | Install, maintain, service and recover refrigerant from systems containing less than 3 kg of F gas, or less than 6 kg if hermetically sealed |
| Category III | Recover refrigerant only, within the same charge thresholds |
| Category IV | Check equipment for leaks, where the refrigeration circuit is not broken into |
A typical domestic wall-mounted split sits below 3 kg, so Category II covers it; larger multi-split and VRF systems can exceed that charge and need Category I. Awarding bodies named in current guidance include City & Guilds, BESA and LCL Awards, with CITB listed as no longer issuing new F gas qualifications. Unlike company certification, no expiry period is stated for the personal qualification.
What the law counts as installation
The reason a split system cannot be treated as an appliance sits in a definition. Article 2(20) of Regulation (EU) 517/2014 defines installation as joining two or more pieces of equipment or circuits containing, or designed to contain, fluorinated greenhouse gases, with a view to assembling a system in the location where it will be operated, that entails joining together gas-carrying conductors of a system to complete a circuit — irrespective of the need to charge the system after assembly.
That closing clause disposes of the pre-charged argument: a unit sold with refrigerant already in it is still being installed the moment the pipework is joined. Article 2(21) likewise puts repairing leaks inside maintenance or servicing.
Nor does the hermetically sealed exemption help. Article 2(11) of Regulation (EU) 517/2014 reserves that term for equipment in which all fluorinated greenhouse gas containing parts are made tight by welding, brazing or a similar permanent connection, with a tested leakage rate of less than three grams a year — which pipework joined on site does not meet. A plug-in portable is a different object again: it is not piped up on site, and it sits outside the rules that govern fixed systems. The differences between system types matter legally as well as practically.
Selling a pre-charged system is a duty on the seller
Article 11(5) of Regulation (EU) 517/2014 is short and specific: non-hermetically sealed equipment charged with fluorinated greenhouse gases may only be sold to the end user where evidence is provided that the installation is to be carried out by an undertaking certified in accordance with Article 10 of that Regulation.
The duty sits on the seller. Government guidance sets out the steps: ask the end user for the details of the qualified technician who will install the equipment, get those details — guidance says they should be in writing — and check they are valid. None of it applies to hermetically sealed equipment, and no retention period is prescribed for these installer records.
This is where do-it-yourself installation runs aground. The obstacle is not a rule against owning a split system: it is that installing one means completing a refrigerant circuit, and that act requires a personal F-gas qualification of the appropriate category. Anyone without one doing the work is working unlawfully, whoever supplied the equipment.
Fitting a fixed system in a home is controlled building work
The second regime is entirely separate from the first, and it applies whether or not the F-gas side is in order. Regulation 2(1) of the Building Regulations 2010 defines fixed building services to include fixed systems for air conditioning, which makes such a system a controlled service because Part L of Schedule 1 imposes a requirement on it. Regulation 3(1)(b) makes providing a controlled service building work. Regulation 12(2) then requires a building notice or an application for building control approval with full plans, and regulation 12(6)(a) supplies the escape — unless the work is one of the descriptions in Schedule 3 and is carried out by a person registered for that scope.
The relevant scope is Schedule 3 item 6: installation of an air conditioning or ventilation system in a dwelling, that does not involve work on a system shared with other dwellings. Item 5 is the equivalent scope for buildings other than dwellings.
The point that matters when reading any credentials list: this is a different registration from the electrical one. An electrical competent person registration does not confer the Schedule 3 item 6 scope, and neither has anything to do with refrigerant handling. Three scopes, three registrations, with overlapping operator names.
The electrical circuit is notified separately
Approved Document P, the statutory guidance on Part P in England, names this technology by example. Paragraph 2.2 applies Part P to electrical installations in a dwelling-house or flat and to parts of the installation outside the dwelling, giving as its own examples fixed lighting, photovoltaic panels on roofs, and air conditioning units attached to outside walls.
Whether the work is notifiable turns on the circuit rather than the appliance. Regulation 12(6A) makes three things notifiable in a home: installing a new circuit, replacing a consumer unit, and any addition or alteration to an existing circuit in a special location. Because a fixed system normally needs its own dedicated circuit back to the consumer unit, the electrical work is notifiable in those cases. That is a common outcome in older Yorkshire housing — Victorian terraces, 1930s semis, ex-colliery estates, converted lofts — where a spare way on the consumer unit cannot be assumed.
Approved Document P sets out three certification routes: self-certification by a registered competent person, a registered third-party certifier, or a building control body. Under the first, an electrical installation certificate to BS 7671 is completed, and within 30 days of the work being completed a Building Regulations compliance certificate is issued to the occupier while the information passes to building control. Schedule 3 item 8 is the scope for fixed low or extra-low voltage electrical installations in dwellings. One limit: Approved Document P is headed for use in England, and Wales operates a divergent Part P regime.
Enforcement, and what MCS has to do with it
Government guidance is direct: it is against the law to work with F gas without the correct certification, and a business that does so could receive a civil penalty. Enforcement runs through Schedule 4 to SI 2015/310, inserted for England and Scotland in April 2018, which decides civil penalties on the balance of probabilities and bars one where the act has already led to a criminal conviction. In England and Scotland that is a civil regime rather than the broad criminal one older trade material describes: after the 2018 amendment only intentional release of F gas remained a criminal offence there, while Wales and Northern Ireland kept the wider criminal offences under a separate version of the same regulation. Great Britain also runs its own F-gas rules, based on the assimilated version of Regulation 517/2014, so the tighter European phase-out timetable quoted on non-UK sites is no guide to what is lawful here.
One frequent confusion: MCS certification is a separate matter from the three regimes above. MCS is a certification scheme for microgeneration technologies, and it is not one of the three authorisations this guide sets out. MCS has not yet opened air-to-air certification to installers, and its consumer guidance still lists the technology as coming soon — which matters when reading grant claims, and is drawn out further in the comparison of air conditioning and air-to-air heat pumps.
Larger systems bring an ongoing duty on the operator
Above a certain size, installation is not the end, and the duty is not confined to commercial buildings. Under the Energy Performance of Buildings (England and Wales) Regulations 2012, an air conditioning system with an effective rated output of more than 12 kW must be inspected by an energy assessor at intervals not exceeding five years, with fixed penalties for failing to hold a valid report or produce one on request. The duty falls on whoever controls the operation of the system, usually the building owner or manager rather than a tenant. Aggregation is conditional, not automatic: units count as one system only where a relevant person can control the temperature of more than one of them. Accredited air conditioning energy assessment is a separate accreditation again.
What compliance actually looks like on paper
A compliant fixed installation in an English home means a certified business doing the refrigerant work with qualified individuals, the system self-certified under Schedule 3 item 6 or notified to building control, and, where the job needs a new circuit, that circuit certified and notified under Part P. Three distinct obligations — and satisfying one says nothing about the other two.
It also explains why a specification cannot be settled from a model number alone. The refrigerant charge decides the qualification category; the circuit decides the notification route; the calculated heat gain decides the equipment. The sizing calculation the English guidance describes is the front end of that same chain, and the VAT treatment of air conditioning turns on the same fixed-versus-portable distinctions.