Arnica Cedar Square Sauna with Adjustable Benches & Windows – Harvia Heater Included

The outdoor sauna has moved from luxury differentiator to expected feature on high-performing short-term rental properties — and the gap between hosts who have one and those who don't is showing up in nightly rates, booking velocity, and review scores. The Arnica Cedar Square Sauna is built for hosts who want that edge, without giving up interior comfort or photographic appeal to get it.

Crafted from aromatic rustic cedar with approximately 1.2-inch thick walls, the Arnica delivers efficient heat retention and year-round outdoor durability. Where barrel saunas curve inward and sacrifice usable corner space, the Arnica's square format converts every square inch of floor area into usable seating and standing room. Guests feel the difference the moment they step inside.

What sets the Arnica apart from standard outdoor box saunas is its combination of adjustable dual benches — which can lay flat or recline at an angle for customized relaxation — and tempered glass windows that bring natural light into the interior and create an open, airy feel that guests remember long after checkout.

Available in two sizes — 4-person and 6-person — the Arnica ships with a full accessories package, weather-resistant shingles, and a UL-certified Harvia KIP heater made in Finland. Everything you need to go from delivery to first session is included.

A Cedar Square Sauna Built for Space, Light, and Guest Comfort

The Arnica is designed from the ground up for outdoor installation — not adapted from an indoor unit and rebranded. Every material choice, from the rustic cedar construction to the stainless steel hardware and heater, is selected for performance across seasons and climates.

Why the Square Format Maximizes Usable Interior Space

Barrel saunas curve inward — which means the walls slope away from occupants on both sides, reducing the effective floor area and the comfortable seating width. The Arnica's square geometry uses the full footprint. Every corner, every inch of bench length, and every square foot of floor space is available to your guests.

The interior gives four to six adults genuine room to sit, stretch, and move — not a forced configuration where everyone is pressed together. A temperature range of 158–194°F delivers an authentic traditional sauna experience, from a gentle warm session to a full high-heat Finnish ritual, across the full width of a properly proportioned interior.

The Harvia KIP heater powers the system with an adjustable dial and an auto 60-minute shut-off for safety and energy efficiency. Guests control their session without you having to manage the heater between turns.

Adjustable Benches and Tempered Glass Windows: The Details That Define the Experience

The Arnica's dual benches adjust between flat and angled positions, giving guests the flexibility to lie back for a full-body session or sit upright for a more traditional experience. It's a small mechanical feature with a meaningful impact on how long guests stay in and how positively they describe the experience afterward.

The tempered glass windows are equally important. An outdoor sauna with no natural light connection can feel claustrophobic — particularly for guests who are new to sauna culture. The Arnica's windows bring the outside in, let guests watch the evening settle across your property, and give the interior a design-forward quality that photographs well and feels premium in person.

Rustic Cedar Construction: Built to Weather and Age Beautifully

Western red cedar is the material of choice for outdoor saunas worldwide — not by tradition alone, but because it genuinely outperforms alternatives in high-heat, high-humidity environments. Cedar's natural oils resist moisture absorption, warping, and decay, which means the Arnica holds its structural integrity season after season without demanding constant maintenance.

The approximately 1.2-inch (30mm) thick walls provide meaningful thermal insulation — keeping heat in during sessions and protecting the interior from ambient temperature swings between uses. Weather-resistant shingles are included for roof installation, completing the exterior weatherproofing from day one. This is a unit built to live outdoors year-round.

Why STR Hosts Are Adding Outdoor Saunas to Their Listings

Outdoor saunas have crossed from aspirational amenity to booking-driving infrastructure on premium short-term rental properties. Listings featuring a sauna command meaningfully higher nightly rates, attract longer stays, and generate the kind of enthusiastic reviews that build Superhost status.

The Amenity That Commands Higher Nightly Rates

Sauna is no longer a niche wellness feature — it's a mainstream search filter on major booking platforms. Guests who search for properties with saunas are committed, high-intent travelers willing to pay a premium for the right property. Adding the Arnica doesn't just upgrade your amenity list — it repositions your listing in a higher nightly rate bracket.

Group bookings, wellness retreats, corporate offsites, and couples' getaways all skew toward sauna-equipped properties when the option exists. The complete accessories package — included at no additional cost — means your listing photos show a fully equipped wellness installation from day one.

What the Harvia KIP Heater Means for Guest Experience

Harvia is Finland's most recognized sauna heater brand — and Finland is the country that invented the modern sauna. The KIP model is a UL-certified electric heater that reaches operating temperature reliably, holds it consistently, and accepts 35 lbs of sauna stones for authentic löyly — the steam ritual at the heart of traditional Finnish sauna culture.

The adjustable dial gives guests precise control over their session temperature within the 158–194°F range, while the auto 60-minute shut-off provides safety and energy management without requiring host intervention. For hosts, a reliable heater means fewer service calls, fewer negative reviews citing temperature issues, and more confident recommendations to guests who have never used a sauna before.

Who This Is For / Who It's Not

This outdoor sauna is the right fit if you:

✔ Want the highest-ROI amenity upgrade available for a premium STR property
✔ Are outfitting a property that attracts wellness travelers, group bookings, or couples' retreats
✔ Want maximum interior floor space — the square format uses every inch vs. a barrel's curved walls
✔ Want natural light and outside views inside the sauna — the tempered glass windows deliver both
✔ Need a fully accessorized sauna with no supplemental purchases required
✔ Want an amenity that photographs beautifully and commands a higher nightly rate bracket

This may not be the right fit if you:

✖ Are looking for a plug-in 120V unit — the Harvia KIP heater requires 220–240V professional electrical wiring
✖ Need a covered exterior cooling/seating area attached to the sauna — see the Liatris Barrel Sauna for a front porch canopy option
✖ Are managing a property in a jurisdiction with strict electrical permit requirements and no budget for licensed installation

What Owning This Looks Like

Picture your guests settling into the Arnica as the sun goes down — bench reclined, windows framing the evening outside, sauna stones hissing with the first ladle of water. They stay longer than they planned. They go in for another round. They mention it by name in their review.

A fully equipped outdoor sauna session for up to six guests — no supplemental gear required. An evening wellness ritual that becomes the centerpiece of your guests' stay and the story they tell when they get home. A listing differentiator that filters your booking inquiries toward higher-value, longer-stay guests. A long-term outdoor installation that appreciates in listing value as sauna demand continues to grow.

The Arnica isn't an amenity you add to check a box. It's an investment in the kind of guest experience that builds a reputation — and a booking calendar — that keeps filling itself.

Available Sizes

The Arnica is available in two sizes. All features, materials, accessories, and the Harvia KIP heater are included in both — the difference is interior length, total footprint, and heater wattage. Dimensions shown in the specifications table reflect the 6-person size; select your variant to view size-specific details.

4-Person — ideal for couples, small groups, and STR properties where footprint matters. Seats four adults comfortably with full bench length. 4.5 kW Harvia KIP heater.

6-Person — built for group bookings, wellness retreats, and STR properties that attract larger parties. Additional bench length and floor area accommodate six adults without compromise. 6 kW Harvia KIP heater for the larger interior volume.

For questions about which size is right for your property, contact our team at sales@optimaloutdooroasis.com.

Product Specifications & What's Included

What's Included (both sizes):

• Rustic cedar square sauna structure with tempered glass door and windows
• Weather-resistant roof shingles
• UL-Certified Harvia KIP electric heater (4.5 kW for 4-person; 6 kW for 6-person)
• 35 lbs. of sauna stones
• Sauna lamp with shade (4-person confirmed; please verify for 6-person at time of order)
• Thermo-hygrometer
• Wooden sauna bucket with plastic liner
• Wooden water scoop
• Wooden sand timer

What's Not Included:

• 220–240V electrical supply and wiring (professional installation required)
• Foundation or base platform
• Professional assembly labor

Downloadable Resources

User Manual & Complete Setup Guide — contact sales@optimaloutdooroasis.com to request.

Shipping & Installation

The Arnica Cedar Square Sauna ships free to all contiguous US addresses — no PO Boxes. Orders are processed within 12–24 hours Monday through Friday. Due to the weight and dimensions of this unit, shipment is via LTL freight and typically arrives within 7–20 business days. Rural shipping surcharges may apply and will be calculated at checkout.

Inspect your delivery carefully before signing off with the freight carrier. Document any damage to packaging or product before accepting — freight damage claims require documentation at time of delivery.

Assembly is DIY with the included setup guide and typically requires multiple people given the unit's weight and component size. The Harvia KIP heater requires a dedicated 220–240V electrical circuit — professional wiring by a licensed electrician is required before first use. We strongly recommend coordinating electrical installation prior to or immediately following delivery.

For questions about your order, delivery coordination, or installation support, contact our team at sales@optimaloutdooroasis.com.