The short answer
It depends on the heater rating. A small infrared cabin of around 3kW or less can often plug into a standard 13-amp socket, ideally on its own circuit, with no rewiring. Anything larger — most traditional electric saunas and bigger infrared models — draws more than a 13-amp socket can supply, so it must be hard-wired onto a dedicated circuit, commonly rated around 32 amps, by a qualified electrician. In England and Wales this fixed electrical work falls under Part P of the Building Regulations, so it must be done by a registered competent electrician (or notified to building control). Saunas are a high-risk, hot and humid environment, so the wiring and the heater's safety controls are not a DIY job for anything beyond a plug-in cabin.
The question on every sauna install is whether you can just plug it in or need an electrician. For a small infrared cabin it is often the former; for a traditional or larger sauna it is firmly the latter. Here is where the line sits.
The rules in brief
- 3kW or less infraredoften plugs into a 13-amp socket
- Over 3kWhard-wired dedicated circuit
- Typical traditional heaterneeds ~30–40A supply
- Who does itqualified, registered electrician
- RegulationPart P, Building Regulations
Plug-in versus hard-wired
Small infrared saunas — typically one- to three-person, low-wattage models around 3kW or less — generally run from a standard 13-amp UK socket, ideally on a dedicated circuit, with no electrical upgrade. Once you go above about 3kW, the load exceeds what a 13-amp socket can safely carry, so the sauna must be hard-wired into its own dedicated circuit at the consumer unit. A 4.5–6kW traditional heater usually needs around a 30-amp supply, and 7.5–9kW heaters more again. That work — running the cable, fitting the circuit and connecting the heater's controls — is for a qualified electrician.
Part P and why it matters
In England and Wales, installing a new dedicated circuit for a sauna is notifiable work under Part P of the Building Regulations. That means it must be carried out by an electrician registered with a competent-person scheme, or otherwise notified to and signed off by local building control. The reason is simple: a sauna combines high power, heat and moisture, which makes correct circuit protection, earthing and heater controls a genuine safety matter. Using a registered electrician gives you the certificate that confirms the work meets the regulations — useful for insurance and for selling the home later.
| Sauna | Electrician needed? |
|---|---|
| Small infrared, ~3kW or less | Often plug-in — no rewiring |
| Larger infrared, over 3kW | Yes — dedicated circuit |
| Traditional electric (4.5–9kW) | Yes — dedicated 30–40A+ supply |
| Any new circuit (England & Wales) | Yes — notifiable under Part P |
General guidance — confirm your own case with a qualified electrician. Source: UK electrical safety and supplier guides.
Want the electrics handled properly?
We'll match you with a vetted sauna supplier or installer who arranges the dedicated supply through a qualified, registered electrician and provides the Part P certificate where the work is notifiable.
Frequently asked questions
Do I need an electrician to install a sauna?
For a small infrared cabin of around 3kW or less that plugs into a standard 13-amp socket, often not. For most traditional saunas and larger infrared models over 3kW, yes — they must be hard-wired onto a dedicated circuit by a qualified electrician, and the new circuit is notifiable under Part P in England and Wales.
Can a sauna run from a normal plug socket?
A small low-wattage infrared sauna (around 3kW or less) can usually plug into a standard 13-amp socket, ideally on its own circuit. Anything more powerful draws too much current for a socket and must be hard-wired into a dedicated circuit.
What size electrical supply does a traditional sauna need?
A typical 4.5–6kW heater usually needs a dedicated circuit of around 30 amps, while 7.5–9kW heaters need 40–50 amps or more. The exact requirement depends on the heater, and the circuit must be fitted by a qualified electrician.
Sources & further reading
- Electrical Safety First — Building Regulations (England)
- Eden Hut — sauna electrical requirements, complete home guide
Figures on this page are typical UK ranges drawn from published sources and depend on your specific sauna, home and electricity tariff. Running costs assume about 27p per kWh. They are guidance, not a quotation.