Buying
Wood-fired vs electric sauna heaters
One needs a certified circuit, the other needs a flue and possibly a DEFRA-exempt stove. The rules decide this more often than the romance does.
Most people arrive at this question wanting wood and leave with electric, and the reason is rarely the heat. It is that a wood-fired sauna is a solid fuel appliance with a chimney, and in a lot of British gardens that brings rules an electric heater never triggers. Settle the legal question first, then decide which heat you actually want.
| Electric | Wood-fired | |
|---|---|---|
| Heat-up | 30-40 minutes, unattended | 45-60 minutes, tended |
| Control | Thermostat and timer | Manual, by the fire |
| Cost per session | About £1.57 | £4-£7 in logs |
| Install | Certified circuit | Flue, hearth and clearances |
| Smoke control area | No restriction | Needs an exempt appliance |
| Running noise | Silent | Crackle and draw |
The smoke control question comes first
Large parts of urban and suburban Britain sit inside smoke control areas, and inside one, wood counts as an unauthorised fuel. You can only burn it in a DEFRA-approved exempt appliance. Emitting smoke from a chimney in a smoke control area carries a penalty of up to £300, and buying unauthorised fuel for a non-approved appliance carries a fine of up to £1,000, both set out in the government's smoke control area rules.
The catch for sauna buyers specifically is that most wood-burning sauna stoves are not on the exempt list, which is aimed at domestic room heaters. Before ordering anything wood-fired, check your address against your council's smoke control map and check the exact stove model against DEFRA's register of exempt appliances. If the model is not on it and you are in a controlled area, that is the end of the decision.
What each one costs to install
Electric costs more to install and less to run. Wood is the reverse, and the gap is wider than most people expect once kiln-dried logs are priced properly.
- Electric: £300 to £800 for a dedicated circuit, certified by a registered electrician
- Wood: £400 to £900 for a twin-wall flue kit, heat shielding and a non-combustible hearth
- Wood also wants a dry log store, which is either a build or a purchase
- Electric adds nothing further; wood adds an annual chimney sweep at £60 to £100
Neither figure is optional. The electrical route is fixed by regulation, and the dedicated circuit a heater needs has to be installed and certified by a registered electrician whichever cabin you buy. The flue route is fixed by physics and by the manufacturer's clearance distances, which are not negotiable on a timber building.
How the heat differs
A well-run wood stove produces a softer, more variable heat, and the löyly from a large mass of stones over a firebox is genuinely different from a compact electric element. Sauna traditionalists are not imagining this. The trade is that the temperature drifts, you feed it during the session, and the last 20 minutes are cooler than the first.
Electric holds a setpoint. You set 90°C, walk out an hour later, and it is 90°C. For anyone using a sauna several evenings a week, that consistency is the entire product, and it is why electric dominates the cabins on our ranking of the best outdoor saunas despite the wood-fired romance.
Placement changes with the fuel
A flue changes where the cabin can go. Smoke has to clear neighbouring windows, the stove needs clearance from combustible cladding, and sparks near a fence are the single most common source of neighbour friction with garden saunas. Electric cabins can sit anywhere the cable reaches.
Height matters too, because the flue is part of the building for permitted development purposes. A 2.2m cabin with a 60cm flue is not a 2.2m building, and the Planning Portal's 2.5m limit within 2m of a boundary applies to the overall height. That is exactly the sort of detail that decides whether a garden sauna needs planning permission.
Which to buy
- Buy electric if you are in a smoke control area, if the sauna will be used on weeknights, or if nobody in the house wants to tend a fire
- Buy wood if you are rural or outside a controlled area, the sauna is a weekend event, and the fire is part of what you are buying
- Buy wood if there is no practical route for a supply cable to the bottom of the garden, which is a real and underrated case
- Buy electric if the cabin is small, since a compact room reaches temperature fast and wastes the stove's advantage
Whichever fuel wins, the output still has to match the room, and sizing a heater to cabin volume works the same way for a stove as for an element. The ongoing figures behind the cost comparison above sit in what a sauna costs to run, and the fuel is one of the six decisions that choosing a home sauna settles in order.
Frequently asked questions
Can I have a wood-fired sauna in a smoke control area?
Only if the stove is a DEFRA-exempt appliance, and most sauna stoves are not on that list. Check the specific model against DEFRA's register before ordering, because in a controlled area a non-exempt stove cannot legally burn wood.
How do I know if I am in a smoke control area?
Contact your local council's environmental services team, which holds the map for your area. Smoke control areas cover much of urban and suburban England and are not obvious from the street.
What is the fine for burning wood illegally?
Up to £300 for emitting smoke from a chimney in a smoke control area, and up to £1,000 for buying unauthorised fuel for use in a non-approved appliance. Both are set out in the government's smoke control guidance.
Which heats up faster, wood or electric?
Electric, by roughly 15 to 20 minutes. A correctly sized electric heater brings a garden cabin to temperature in 30 to 40 minutes on a timer, while a wood stove takes 45 to 60 and has to be lit and tended throughout.
Is a wood-fired sauna cheaper to run?
No. A session burns roughly 10kg to 15kg of dry hardwood, which is £4 to £7 at UK kiln-dried prices, against about £1.57 of electricity for a 6kW heater. Wood is a preference, not a saving.
Does a wood-fired sauna need a chimney sweep?
Yes, annually for regular use, at £60 to £100. Skipping it risks a flue fire and will usually invalidate both the appliance warranty and any related insurance claim.
Do I need building regulations approval for a sauna flue?
The flue installation itself must meet the requirements for solid fuel appliances, including clearances and the hearth. Use a HETAS-registered installer who can certify the work, which is the equivalent of using a Part P electrician on the electric route.
Can a wood-fired sauna be used indoors?
Almost never in a domestic setting. The flue routing, clearances and combustion air requirements make it impractical inside a house, which is why indoor cabins are electric with very few exceptions.
Does the flue count toward planning height limits?
Yes. The flue is part of the building's overall height for permitted development, so a 2.2m cabin with a 60cm flue exceeds the 2.5m limit that applies within 2m of a boundary.
Can I convert an electric sauna to wood-fired later?
Rarely worth it. The cabin needs a hearth, heat shielding and a flue penetration through the roof, and the timber around the stove position has to be rated for it. Decide the fuel before you order the cabin.