Die richtige Sauna-Ausstattung: Ofen, Gebäude und alles drumherum

Hardware is where sauna dreams meet invoices. Every choice below is a trade between guest experience, running cost, labour, and regulation — and the right answer depends on the business model and site you've already chosen. Choosing hardware first and a model second is the classic beginner mistake; this guide assumes you're doing it in the right order.

Wood-fired versus electric stove

The defining choice, and there is no universally correct answer.

Wood-fired delivers the löyly most enthusiasts prize — löyly being the character of the steam when water hits the stones: soft, enveloping heat rather than a dry sting. The living fire is part of the product, and for waterfront and rural saunas it's often what guests come for. The costs are real: 45–90 minutes of heating before every session, someone to feed the fire throughout, firewood logistics (buying, drying, storing, carrying — roughly 1–2 m³ per week of regular commercial use, illustrative), ash disposal, chimney sweeping, and the strictest fire-safety rules. Wood-fired means a human is always working while the sauna is hot.

Electric buys you predictability: switch on, reach temperature in 30–60 minutes, no fuel handling, timers and remote control, easier permits in urban buildings. Modern electric stoves with generous stone mass produce genuinely good löyly — the "electric saunas are harsh" reputation mostly comes from undersized stoves with too few stones. Costs: a commercial-scale stove typically draws 9–15 kW, so at, say, €0.20/kWh a heavy operating day can run €15–30 in electricity (illustrative), and you may need a three-phase supply upgrade. Regulation shifts from fire authority to electrical certification.

Practical rule of thumb: staffed sessions at an atmospheric site favour wood; long unstaffed opening hours, urban buildings, and private-hire self-service favour electric. Some venues run both — a wood-fired main sauna and an electric one for flexible hours.

Building type

Purpose-built cabin or building. Best experience, best insulation, best longevity — and the highest cost and longest permit path. The right call for a permanent venue with a secure long lease or owned land.

Container, trailer, or floating conversions. Faster and often cheaper to deploy, movable if the site doesn't work out, and sometimes permit-lighter. The catches: insulation and ventilation retrofits are harder than they look in a steel box, trailers cap your capacity and add road-legality questions, and floating platforms add marine maintenance forever. As demand-testing vehicles, though, they're excellent — a trailer sauna can validate a market before you commit to a €100,000 build (see mobile models).

Barrel saunas. The cheapest fast route to a working sauna (often €8,000–20,000 delivered, illustrative). Honest assessment: they heat quickly, look charming, and work well for private hire up to ~6 people — but bench geometry is compromised (feet cold, head hot), capacity is limited, and thin walls mean higher heating costs in deep winter. Fine as a starter or a second unit; rarely the backbone of a high-volume venue.

Capacity sizing

Count bench metres, not marketing capacity: a comfortable adult needs about 60 cm seated, and Nordic bathers expect to be able to lie down off-peak. A "12-person" sauna is often a pleasant 8-person sauna. Size to your model:

• Private hire: 6–10 seats covers most groups.
• Drop-in: capacity is your revenue ceiling — do the capacity maths before deciding, and remember two medium saunas often beat one big one (flexibility, maintenance without full closure, gender-separate or quiet sessions).
• Aufguss programming (aufguss: a hosted ritual where a sauna master distributes steam with a towel) needs a larger room, tiered benches, and space for the host to work.

Changing rooms, showers, and the bits guests judge

Guests forgive a rustic hot room; they do not forgive a grim changing room. Budget seriously for: enough hooks and benches for a full changeover of guests (two sessions overlap at the door), warm dry floors, showers scaled to capacity (one per 6–8 guests as a working minimum), mirrors, and somewhere dry for winter coats. Hygiene inspections focus here too — the standards are covered in cleaning and hygiene.

Cold plunge options

In rough order of preference and descending wow-factor:

1. Sea or lake access — unbeatable, free to "run", but demands ladders, lighting, rescue equipment, and winter avanto maintenance (see safety procedures).
2. Ice baths / plunge tubs — engineered cold anywhere; either refilled and dumped (cheap, laborious) or chilled and filtered (convenient, €3,000–10,000+ illustrative, plus water-treatment duties).
3. Cold showers — the minimum viable contrast. Every sauna should have them regardless.

Ventilation basics

Bad ventilation is the most common defect in amateur builds and it ruins everything: stale heavy air, drowsy guests, mould in the structure. Principles: fresh air in near the stove, exhaust out low on the opposite side (the classic Finnish arrangement, since hot air needs to be pulled down through the bathing zone), and continuous air exchange sized for occupancy — roughly 6 air changes per hour is the common design target. In mechanical-ventilation buildings, involve an HVAC designer who has done saunas before. This is the wrong place to improvise.

Accessibility

Design for it from the start: step-free route to the changing room, a bench at transfer height, grab rails at the door and plunge steps, and a shower seat. Retrofitting accessibility into a barrel or trailer is nearly impossible; into a purpose-built sauna, trivial — if planned. Accessible saunas also serve your largest growth demographic: older regulars are the most loyal bathers you will ever have.

Materials and durability

• Aspen and alder — the classic Nordic bench woods: low resin, cool to the touch, pale (aspen) or warm-toned (alder). Aspen shows dirt sooner; both are comfortable and safe at temperature.
• Thermo-wood (heat-treated aspen, alder, or pine) — dimensionally stable, rot-resistant, darker; excellent for benches and exteriors in commercial use, at a price premium.
• Spruce/pine panelling — fine for walls and ceilings, not for benches (resin pockets get hot and sticky).
• Commercial reality: benches take enormous wear. Design them to be removable and refinishable, and put annual sanding/replacement into your maintenance plan.

Buying used versus new

Used barrel saunas, trailers, and stoves circulate constantly and can halve startup costs. Inspect ruthlessly: rot at the base and around windows, cracked stove interiors, corroded flues (a used chimney is rarely worth reusing — budget a new one), and mould smell in the insulation. Ask why it's being sold; "we never got the bookings" is market information, not just a bargain. For stoves in commercial use, confirm the model is certified for your installation and that parts (stones, grates, elements) are still available. New hardware with a warranty often wins once you price your own repair hours honestly.

However you spec it, photograph the finished setup well — your hot room, plunge, and changing space are the product shots that fill your calendar once you list on a platform like GoToSauna.

Related reading

• Writing a lean sauna business plan
• Choosing a location
• Sauna maintenance