Sauna Installation UK: Base, Access, Build and Costs
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Most of what goes wrong with a garden sauna goes wrong before it is switched on. A base that was not quite level. An access route nobody measured. An electrician booked for the wrong week, or not booked at all.
This guide covers what actually has to happen to get a sauna working in a British garden — the base, the access, the build, the connection — and what each part realistically costs.
The short version
- Prepare a level, load-bearing base before delivery day.
- Check your access route — width, corners, gates, overhead branches.
- Take delivery — usually a pallet to the kerb or driveway.
- Build the cabin — typically a day for two people, or use an installation service.
- Connect the heater — a qualified electrician for electric; our fitters for gas or wood-fired flues.
Steps 1 and 2 are where people come unstuck, and they are the two you can sort out today.
1. The base
A sauna needs a base that is level, well-drained and load-bearing. Not roughly level — actually level, because a barrel or cabin that sits out of true will fight you throughout the build and may never seal properly at the door.
What works
- Concrete slab — the gold standard, and the only sensible answer for heavy log cabins or pre-assembled buildings.
- Paving slabs on a compacted sub-base — perfectly good for most flat-pack saunas, and easier to arrange.
- Compacted gravel — acceptable for lighter cabins on well-draining ground. Not for anything approaching a tonne.
- An existing deck — only if it is rated for the load. Most garden decking is not designed for 700–1,200 kg in one spot.
How much weight are we talking about?
More than people expect. A compact cube is around 500–600 kg. A mid-size barrel is 700–950 kg. A solid log cabin runs to 950 kg before the heater goes in, and a fully assembled sauna house is heavier still. That is before you add four to six people and a stove full of stones.
Drainage
Whatever the base, water must run away from it. Timber sitting in standing water will fail regardless of how it was treated. Leave the ground falling gently away, and do not box the cabin in so tightly that air cannot circulate underneath.
2. Access — the step most people skip
This is where deliveries genuinely fail, and it is entirely avoidable.
Flat-pack saunas arrive as panels on a pallet. The individual pieces go through a standard side gate, but the pallet itself needs somewhere to be put down — usually a driveway or hard standing, because a pallet truck will not cross a lawn.
Pre-assembled saunas arrive as one finished building. That is the simplest installation there is — placed, connected, working the same day — but it needs a route wide enough for the whole cabin and machinery to place it. A 2.4 m wide building will not go down a 1.2 m alley, and no amount of goodwill on the day will change that.
Measure these before you order
- Narrowest point of the route, including gate posts and downpipes
- Tight corners — a long pallet needs swing room
- Overhead: branches, cables, a carport roof
- Ground firmness — can a pallet truck or crane actually get there?
- Where the lorry will stop, and whether it can turn
Send us photographs of the route before you order. We would far rather tell you a particular model will not fit than have it turn up and go back on the lorry.
3. Building it
Flat-pack saunas from good manufacturers arrive as numbered, pre-cut panels with instructions. A barrel goes together faster than most people expect — the shape is self-jigging. A cube or cabin is more like flat-pack furniture at building scale.
Realistically: a day for two competent people on most cabins, longer on the largest. You will want a second person regardless — glass panels and roof sections are not one-person jobs.
Using an installation service
Our construction service starts at £500, with mileage beyond a certain distance — send a postcode for a firm quote.
What you get for it beyond saved time: we apply insulating paste between every panel as we build. Gaps between panels are the most common reason a sauna underperforms — it reaches temperature slowly, loses it quickly, and never quite feels right. That is a build-quality problem, not a heater problem, and it is invisible once the cabin is closed up.
4. Connecting the heater
Electric
An electric sauna heater needs a dedicated circuit installed by a qualified electrician, and in most cases that is notifiable work under Part P. Budget separately for it — a garden supply run from the consumer unit is commonly £400–£1,200 depending on distance and how easily the cable can be routed.
Larger heaters may need more than a standard domestic circuit. Confirm the requirement before you order the heater, not after.
Wood-fired
No electrical supply needed at all. The flue has to be cut and fitted correctly with proper clearances to combustible timber — that is a job for someone who has done it before. Our fitters install the stove and check the flue on the day.
Gas
An off-grid propane heater runs from a standard gas bottle, so there is no cable, no trench and no consumer-unit work. For a sauna at the bottom of a garden with no supply, it frequently saves more than the heater costs. We cut the flue and commission the heater on installation day.
What it all costs
| Item | Typical UK cost |
| Sauna cabin | £3,750 – £10,000+ |
| Base — paving on sub-base | £300 – £800 |
| Base — concrete slab | £800 – £2,000 |
| Construction service | from £500 |
| Electrical supply and connection | £400 – £1,200 |
| Gas — flue and commissioning | included with our gas options |
The honest total for a mid-range garden sauna, properly installed, is usually £5,000–£8,000 all in. Anyone quoting a cabin price alone is not quoting the job.
Common questions
How much does sauna installation cost in the UK?
Construction alone starts around £500 for a flat-pack cabin. Add a base at £300–£2,000 depending on type, and electrical work at £400–£1,200 if you are going electric. Gas and wood-fired avoid the electrical cost entirely.
Do I need planning permission?
Usually not — most garden saunas fall under permitted development. Exceptions apply for size, siting near boundaries, listed buildings and conservation areas. See our planning permission guide.
How long does installation take?
A flat-pack cabin is typically a day for two people, plus the electrician's visit separately. A pre-assembled sauna house is placed and connected in a few hours, assuming access works.
Can I install a sauna myself?
Yes, for the cabin — they are designed for it, and the panels are numbered. The heater connection is different: electric work needs a qualified electrician, and a wood or gas flue needs correct clearances to combustible material. That part is not a DIY job.
What if my access is too tight?
Then a flat-pack cabin rather than a pre-assembled one, and possibly a smaller model. Send photographs of the route and we will tell you what will actually fit — before you order, not after.
Ready to look at cabins?
- Garden Saunas — the full outdoor range by size and format.
- Sauna Cabins & Houses — including one delivered fully assembled.
- Nordic Saunas — Estonian-built, flat-packed on a single pallet.
- Gas Sauna Heaters — the route with no electrician.
Also useful: home sauna electrical requirements and sauna running costs.
