The Outpost 4 Person Outdoor Garden Sauna

The Outpost — Premium Insulated Outdoor Sauna

The Outpost is a fully-insulated, premium-build outdoor sauna designed for serious year-round use in any British garden. Built to order at our European workshop and delivered fully assembled, with your choice of Harvia heater and exterior cladding.

Key features at a glance:

• Capacity: 4-6 people comfortably
• Dimensions: 235 × 235 × 240 cm external / 200 × 200 cm sauna room
• Insulation: 10 cm rockwool — full thermal envelope for year-round use
• Frame: C24 structural-grade calibrated timber
• Exterior cladding: Spruce W-profile (standard) or Thermowood W-profile (from +£800)
• Panoramic window: 200 × 200 cm, 8 mm tempered glass
• Benches: 2-tier Linden wood
• Heater: Harvia Cilindro PC90 9.0 kW electric or Harvia Legend 150 wood-burning

Why The Outpost

Engineered to last in the British climate. Built around a structural C24 calibrated frame and clad in W-profile painted timber, the Outpost is designed to handle wet, cold and unpredictable UK weather. The 10 cm rockwool insulation through the walls, ceiling and floor keeps heat where you want it — meaning faster warm-up times, lower running costs, and reliable temperature even on a January morning.

Spruce or thermowood — your call. The standard build comes in painted W-profile spruce, a classic look that takes paint beautifully and weathers well when maintained. Upgrade to thermowood (from +£800) for a darker, harder, more dimensionally stable timber that resists rot, swelling and warping over time. Both options use the same W-profile cladding and are available in our full range of paint finishes.

A panoramic view, day or night. The 200 × 200 cm 8 mm tempered-glass panoramic window turns your sauna into a viewing platform — your garden, the stars, the snow. Paired with discreet LED lighting beneath the benches and behind the backrest plus an exterior lights set, it sets the right atmosphere without overdoing the spa-resort cliché.

Premium sauna-grade interior. Two-tier Linden wood benches sit inside a spruce-clad sauna room. Linden is one of the classic Finnish sauna woods — light in colour, low in resin, and comfortable against bare skin even when the air's hot.

Your choice of heater. Pick the Harvia Cilindro PC90 9.0 kW electric heater for plug-and-play simplicity and digital control, or the Harvia Legend 150 wood-burning stove (chimney included) for the traditional Finnish ritual. Both are properly specified for the cabin volume.

Made bespoke to your taste. Beyond the heater and exterior cladding choices, the Outpost can be further customised with composite WPC exterior cladding, your choice of exterior paint colour (12 finishes), interior sauna room wood, door style, and add-ons like a Himalayan salt wall, sauna accessory set, water tank or wooden heater fence. See the Bespoke Upgrades tab for the full list.

Delivered fully assembled. The Outpost is built, finished and quality-checked at our European workshop and arrives on site ready to position — there's no on-site construction. Because it ships as a complete cabin, placement requires lifting equipment such as a HIAB lorry-mounted crane, mobile crane or telehandler. The right solution and cost depend on your site access and how far the unit has to travel from the road to its final position, so we'll spec and quote the lift alongside your order.

What's included as standard

• Full sauna cabin — C24 calibrated structural frame, W-profile painted exterior (spruce or thermowood per variant), spruce interior cladding, terrace-board floor
• 10 cm rockwool insulation — through walls, ceiling and floor
• Panoramic window — 200 × 200 cm, 8 mm tempered glass
• Glass entrance door (tempered)
• 2-tier Linden wood benches
• LED lighting — under the benches and behind the backrest
• Exterior lights set
• Harvia sauna heater — electric Cilindro PC90 9.0 kW or wood-burning Legend 150 (per variant chosen)
• Chimney (wood-burning variant only) — through-roof flue kit

Specifications

Dimensions

External footprint	235 × 235 cm
External height	240 cm
Internal sauna room	200 × 200 cm
Panoramic window	200 × 200 cm
Installed weight	~1,000 kg

Construction & insulation

Structural frame	C24 calibrated softwood
Exterior cladding	Spruce W-profile (standard) or Thermowood W-profile (from +£800)
Interior cladding	Spruce wood (walls & ceiling)
Floor	Terrace-grade timber boards
Insulation	10 cm rockwool (walls, ceiling, floor)
Window glazing	8 mm tempered glass
Door	Glass (tempered)
Benches	2-tier Linden wood

Heaters

Electric variant	Harvia Cilindro PC90 — 9.0 kW
Wood-burning variant	Harvia Legend 150 (with chimney through roof)

Lighting

• LED strip under benches
• LED strip behind backrest
• Exterior lights set

Capacity

4-6 people seated comfortably. The 4 m² internal floor area gives ample room for the heater, two-tier benches and movement space without crowding.

Bespoke upgrades & customisation

Beyond the heater and cladding choices you make at order, almost every other element of the Outpost can be specified to your project. Talk to us when you place your order and we'll confirm the build before fabrication.

Further exterior cladding upgrade: Composite WPC in black, grey or brown is available on request as an alternative to spruce or thermowood W-profile.

Exterior paint colour — 12 finishes including natural oiled, coal black, golden brown, mahogany, transparent grey, anthracite, light brown, dark grey, dark oak, dark walnut and teak.

Interior sauna room wood:

• Spruce (standard)
• Thermowood (upgrade)
• Linden wood (upgrade)
• Alder wood (upgrade)

Bench wood: Linden/aspen (light tone, standard) or alder (darker tone, on request).

Heater upgrades — beyond the standard PC90 and Legend 150, larger Harvia electric (Cilindro PC90XW 9 kW WiFi, SP90XW WiFi, Legend PO110XW 10.8 kW WiFi) and wood-burning (M3, M3 SL, 20 Pro, 20 Pro SL, Cilindro 16, Legend 300) options are available on request.

Door options: Glass (standard), wooden, or full-glass doors. Window and door glass available in black or mirrored finish (+£300).

Accessories add-ons available:

• Himalayan salt wall with LED
• Sauna accessory set (bucket, scoop, thermometer, timer)
• 30 L or 60 L water tank for chimney (wood-burning only)
• Wooden heater fence

Electrical connection: Cable only, plug-in (230 V or 380 V), connection box, or connection box with 380 V plug.

For pricing on any of the above further upgrades, contact our team when you order — we'll confirm everything on the spec sheet before fabrication begins.

Frequently asked questions

How many people does it seat?
Four to six adults comfortably, or two people lying down on the two-tier bench setup. The 4 m² internal floor area leaves room for the heater, free movement and a relaxed experience without crowding.

Can I use it year-round?
Yes. The 10 cm rockwool insulation through walls, ceiling and floor makes the Outpost a true four-season sauna. Warm-up times stay fast and running costs sensible even in deep British winter.

What's the difference between spruce and thermowood?
Spruce is a classic, lighter softwood that takes paint beautifully and forms the standard exterior cladding. Thermowood (from +£800) is heat-treated to a higher temperature, which removes moisture and resin and gives the wood a darker tone, harder surface and significantly better dimensional stability — it resists rot, swelling and warping over time, which is why it's a popular long-life upgrade for British weather.

What's the difference between the electric and wood-burning variants?
The electric variant uses the Harvia Cilindro PC90 (9.0 kW) — plug it in, set the controls, and it's ready on a schedule. The wood-burning variant uses the Harvia Legend 150 with a through-roof chimney — a more traditional Finnish experience with the sound and smell of a real fire, but requires manual lighting and stocking with firewood.

What kind of base do I need?
A flat, level base capable of supporting roughly 1,000 kg installed weight. A concrete pad, paving slabs, or a suitably reinforced timber deck all work. We'll discuss site requirements at the order stage.

Do you deliver and install?
Yes — UK-wide delivery is available. The Outpost arrives fully pre-assembled, so on-site placement requires lifting equipment: a HIAB lorry-mounted crane, mobile crane or telehandler depending on access and lifting distance. Lifting cost varies by site and is confirmed at quote stage. Lead time is typically 6 to 8 weeks from order, as each unit is built to order with your chosen heater, cladding and finish.

What lifting equipment do I need on site?
The Outpost weighs roughly 1,000 kg and ships as a single pre-assembled unit. We arrange the appropriate lift — typically a HIAB lorry-mounted crane (the most common solution where the truck can park close to the final position), a mobile crane (when the unit needs to travel further or clear obstacles), or a telehandler (useful for tighter or rough-terrain sites). Lifting cost depends on the equipment, your site access and the working distance, and is quoted with your order based on photos or a site visit.

What electrical supply does it need?
The electric heater variant needs a 9 kW supply (typically 3-phase / 380 V for full output; some installations can run on 230 V with appropriate setup). Our team confirms exact requirements with your electrician at order stage. The wood-burning variant only needs power for the LED lighting and exterior lights.

What's the warranty?
5-year manufacturer warranty covers structural and material defects not caused by natural wear and tear; heater warranty is provided by Harvia direct. Full warranty terms are confirmed at order stage.

What maintenance does it need?
Outdoor saunas need minimal maintenance: occasional retreatment of the exterior paint every few years, periodic cleaning of the bench wood, and standard sauna heater maintenance per Harvia's guidelines. Wood-burning chimneys should be swept annually.