Steam & Oak Cube Sauna 2m — Spruce or Thermowood, 5 Person

Steam & Oak Cube Sauna 2m — build it your way, in spruce or thermowood

The 2m Cube is the size most UK gardens actually want: a genuine five-seat sauna room with a proper panoramic glass front, on a footprint that still leaves you a garden. It sits between our 1.8m Cube and the 2.4m Double-Shelf — more bench than the 1.8m, less ground than the 2.4m with its porch.

This is a made-to-order cabin. You choose the timber, the heater and the electrical connection at checkout, and it is built to that specification. Nothing here is a stock box with options bolted on afterwards.

Choose your timber — spruce or thermowood

Both walls are 44mm solid timber. The wall is the structure, not a thin cladding over a hidden frame, so what you see and lean against is the building itself. There is no cavity to trap damp and no concealed insulation to fail.

Spruce is the traditional Nordic sauna timber and, at 44mm, a thicker solid wall than most barrels on the market — that timber mass stores heat and gives it back evenly, so the warmth stays steady rather than dropping away the moment the door opens. Thermowood is that same principle with the moisture cooked out of the cell walls, which is what makes it so dimensionally stable outdoors. See Thermowood vs Slow-Grown Spruce for the full comparison.

Choose your heater — wood-fired M3 or electric Cilindro

• No heater — cabin only. Take the shell and fit your own stove.
• Harvia M3 (wood-fired). The classic Finnish log-burning stove. No electrics at all, no standing charge, and the ritual of building the fire. Needs a flue — pick your chimney route on the order.
• Harvia M3 SL (wood-fired, through-wall feed). Same stove, loaded from outside the sauna room through the wall. You feed the fire without letting the heat out and without carrying logs past bathers — the standard choice where the sauna has a porch or anteroom.
• Harvia Cilindro PC90 9kW (electric). The cylindrical stone column — a deep vertical stone mass that gives a softer, rounder löyly than a flat-topped heater, because the steam rises through the whole column rather than off a shallow tray. Needs a dedicated circuit.
• Harvia Cilindro PC90XW 9kW WiFi (electric). The same heater with app control. Set it heating from the train and walk into a sauna that is already at temperature — the single upgrade owners tell us they use most.

Heater prices shown are a holding price pending final supplier confirmation.

Choose your electrical connection

How the cabin arrives wired changes what your electrician has to do on the day — and what it costs you. All four connection options are available:

• Electricity cable only. The cabin is delivered with the cable run and nothing terminated. Lowest cost, most work for your electrician — they specify and fit everything.
• Electric plug-in, 230V or 380V. Terminated to a plug. Simplest route where you already have a suitable outdoor socket on the correct circuit.
• Electricity connection box. A proper consumer connection box fitted in the cabin — your electrician wires into the box rather than building the termination from scratch.
• Electricity connection box with 380V plug. The full arrangement: connection box and a three-phase plug. The fastest commissioning of the four, and the usual choice with a 9kW Cilindro.

Electric heaters need a dedicated circuit installed by a qualified electrician and signed off under Part P — budget £800–£1,500 on top, and book them before delivery. The wood-fired M3 options need no electrical supply for the heater itself.

Build & finish

• Walls: 44mm solid spruce or thermowood
• Benches: Linden / aspen light wood as standard; alder (darker) available
• Bench layout: Two benches facing each other as standard; two-storey L-shape available
• Floor: Terrace decking board
• Roof: Two-layer bitumen shingles — black, grey, red, brown or green
• Glass: 8mm tempered as standard; mirror or black glass available
• Lighting: Standard Harvia light inside, plus 2 external Harvia lights
• Exterior finish: 11 colours from natural oiled through to coal black

Specifications

• Capacity: 5 person
• Use: Outdoor only
• External dimensions (L × W × H): 300 cm × 235 cm × 240 cm
• Wall thickness: 44mm
• Timber: Slow-grown spruce or thermowood
• Weight: ~1,100 kg
• Heater: Harvia M3 / M3 SL wood-fired, or Cilindro PC90 / PC90XW WiFi electric

Options available on request

Beyond the choices on this page, the cabin can be specified with: a front terrace or a +50cm length extension; front and rear panoramic windows; two-storey L-shaped benches; LED lighting under the benches, behind the backrest or around the crown (single colour or 7-colour RGB); a Bluetooth speaker set mounted under the benches; a 30L or 60L water tank on the chimney; a wooden heater fence; stainless steel banding; and a sauna accessory set (bucket, scoop, thermometer, timer). Ask us and we will quote your exact build.

Base & groundworks — what size slab do I need?

This is the question worth answering before you order, because the base has to be ready on delivery day and cannot be corrected afterwards. The cabin footprint is 300 × 235 cm. We recommend oversizing the base so no part of the sauna overhangs and you have a dry margin to stand on.

Concrete specification: 100 mm (4″) of concrete over 100–150 mm of compacted MOT Type 1 hardcore, with A142 or A193 steel mesh in the upper third. That is standard domestic slab practice and comfortably more than this cabin needs.

The load is not the difficult part. The cabin is around 1,100 kg; add five bathers, a heater full of stones, benches and water and you are at roughly 1,700 kg — about 240 kg/m² spread over the footprint. A 100 mm reinforced slab on well-compacted ground carries far more. What matters is flatness and drainage:

• Level to within about 5 mm across the whole base. A cube with a full-height glass door is unforgiving — twist the base and the door stops closing squarely against its seal.
• Do not let water pond under the timber. Either lay a slight fall (about 1:80) away from the door, or lay it dead level and let the surrounding ground drain.
• Leave the bearers proud. The cabin sits on timber base beams, so the shell never touches the concrete directly — that air gap is what keeps the base timbers dry. Don't bed it down solid.

Concrete is not the only option. At this weight all of these are perfectly sound:

• Paving slabs on a compacted sub-base — 50 mm slabs on sharp sand over MOT Type 1. Cheaper, no curing wait, and reversible if you move the sauna later.
• Concrete pads under the bearers — 400 × 400 × 100 mm pads at each bearer point instead of a full slab. Least material, but every pad must be dead level with the others.
• Ground screws — quick, no spoil to dispose of, and good on sloping or awkward-access sites.

A poured slab needs around 28 days to reach full strength — it is walkable within a few days and generally fine to build on at seven. If your delivery date is tight, slabs or ground screws avoid that wait altogether. Send us photos of your site and we will tell you what it needs.

Delivery & site preparation

• Made to order — lead time confirmed at order.
• Delivered assembled or in sections depending on access; we will confirm before dispatch.
• Site preparation: a stable, level base is required before delivery — see the base sizing above. At ~1,100 kg this cabin needs proper ground bearing, not a lawn.
• Access: please check your route to the garden before ordering. Send us photos and we will advise.
• Electrical (Cilindro variants): dedicated circuit, qualified electrician, Part P sign-off.
• Chimney (M3 variants): flue through wall or roof, with clearance from buildings and overhanging trees.

💡 Not sure which configuration? Read our complete UK Sauna Buying Guide, or talk to us — this is a made-to-order cabin and we would rather get the spec right than sell you the wrong one.

Prices on this listing are holding prices pending final supplier confirmation.