The short answer
The part of the building regulations that most often affects an air conditioning installation is the electrical work. In England and Wales a new circuit is notifiable, so it's done by a registered electrician or notified to building control.
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Planning and building regulations are easy to confuse. Planning is about whether something can go in a particular place, including how it looks and the noise it makes. Building regulations are about whether the work itself is done to set standards, and they apply whether or not planning permission was needed.
Which rules cover which part of the job
An air conditioning installation touches several sets of rules, each dealing with a different part of the work.
| Part of the job | Rules | Who deals with it |
|---|---|---|
| Outdoor unit position | Planning | Local council |
| New electrical circuit | Building regulations | Registered electrician or building control |
| Refrigerant pipework | F-gas rules | F-gas qualified engineer |
| Holes through fire-separating walls | Building regulations | Installer |
The planning side is covered in Do you need planning permission? and the refrigerant side in F-gas rules for homeowners. The rest of this guide is about building regulations.
The electrical work
Most air conditioning systems need a dedicated circuit from the consumer unit, rather than a plug in a socket. In England and Wales, adding a new circuit is notifiable work under Part P of the Building Regulations. That means it has to go through one of two routes.
- A registered electrician. An electrician registered with a competent person scheme can certify their own work. The scheme lets the council know, and you receive a certificate confirming the work complies with the Building Regulations.
- Building control. If the person doing the work isn't registered, the work has to be notified to the council's building control team before it starts, and building control checks it.
An isolator switch near the outdoor unit is common, so the system can be switched off safely for servicing. Electrical requirements covers circuits and isolators in more detail.
The paperwork you should get
For a new circuit done by a registered electrician, you would normally expect two documents:
- an electrical installation certificate from the electrician, recording what was installed and the results of their tests
- a Building Regulations compliance certificate, confirming the work was notified through the scheme
If building control dealt with the work instead, keep whatever confirmation they provide.
Responsibility for meeting the regulations rests with the person doing the work, but if work doesn't comply, the owner of the property can end up having to put it right. Asking before work starts who will certify the electrical work, and how, helps avoid gaps later.
Keep the certificates with the rest of the system's documents. A buyer's solicitor is likely to ask for them if you sell, as covered in Selling a home with air conditioning.
Other parts of the regulations
The electrical work isn't the only thing the regulations can touch, though for a typical wall-mounted system the other areas are usually minor.
- Fire separation. Some walls and floors are there to slow the spread of fire, such as those between flats, or between a house and a garage built into it. Any hole made through one for pipes or cables has to be sealed properly afterwards.
- Energy efficiency. The regulations set efficiency standards for fixed heating and cooling systems, including how they're controlled.
- Larger building work. If an installation is part of a bigger project, such as an extension or a loft conversion, the building regulations for that project apply as well.
A good installer will know which of these apply to a particular installation and can explain how each will be dealt with.
Wales, Scotland and Northern Ireland
Wales has its own version of the Building Regulations. A new circuit is notifiable there too, although other details can differ from England.
Scotland has its own building standards system, and Northern Ireland has its own building regulations. The electrical rules work differently in both, so the local council's building standards or building control team is the place to check what applies.
Related guides
- Electrical requirementsMost wall-mounted systems need their own circuit from the consumer unit, often with an isolator switch near the outdoor unit. In England and Wales a new circuit is notifiable building work, so it's done by a registered electrician or notified to building control.
- Do you need planning permission?Usually not in England, where air-to-air heat pumps that aren't used only for cooling count as permitted development if conditions on number, size, position and noise are met. Listed buildings, flats and protected areas follow different rules.
- F-gas rules for homeownersF-gas rules in Great Britain require anyone installing, servicing or removing a split system to hold the right qualification, and ban releasing refrigerant. A typical home system is well below the size that needs mandatory leak checks.
- Why installation needs a certified engineerA split system is joined into a sealed refrigerant circuit on site, and in Great Britain anyone doing that work needs the right F-gas qualification, with the business holding a company F-gas certificate. Poor work can cause leaks, damage and safety problems.