The Outdoor Sauna Kit Buyer's Guide: Everything You Need Before You Buy

Outdoor saunas have moved from Scandinavian novelty to mainstream must-have. If you're building a cabin kit or upgrading an existing property, a sauna is now one of the most practical investments you can make — whether you're doing it for personal use or Airbnb income.

This guide covers everything: why the market is surging, the differences between sauna types, Fireside's two options, what to look for in any sauna kit, permitting realities, and the Airbnb math behind the decision.

Why Outdoor Saunas Are Surging Right Now

Three trends have collided to make outdoor saunas one of the fastest-growing segments in the home improvement and STR market:

• Wellness culture: Cold plunge and sauna protocols have gone from niche biohacking to mainstream. Buyers who wouldn't have considered a sauna five years ago now specifically search for properties that have one.
• Airbnb amenity wars: In competitive STR markets — the Smokies, Blue Ridge, Catskills, Colorado — cabin listings with saunas consistently command a $30–$60/night premium and higher occupancy than comparable properties without one.
• Year-round use: Unlike a pool, a sauna is fully usable 12 months a year. In cold-weather markets, it's actually most popular in fall and winter — the highest-revenue booking seasons.

Fireside's Two Sauna Options

We offer two outdoor sauna kits, built with the same quality standards as our cabin kits. Both are pre-cut, pre-fit, and designed to assemble in a weekend with standard tools.

Backyard Sauna Kit — $7,500

Our classic rectangular cabin-style sauna. Built from the same 70mm Nordic Spruce as our cabin kits — which means exceptional thermal mass, natural aroma, and a structure that holds heat efficiently and lasts for decades. Designed to fit 4–6 people comfortably with a traditional bench layout. The rectangular footprint pairs naturally with cabin builds and works on any level surface — gravel pad, treated timber beams, or a small concrete pad.

Best for: buyers who want the proven cabin-style sauna look, are pairing with an existing cabin build, or prefer Nordic Spruce for thermal performance and aesthetics.

Square Cedar Sauna Kit — $8,500

Our modern square-footprint sauna, built with a cedar interior. Cedar is lighter than spruce, naturally resistant to moisture and insects, and has a distinctive warm aroma that many buyers prefer. The square layout allows for a more open interior arrangement — benches on two or three walls — and the modern profile photographs well for STR listings. Slightly smaller interior than the Backyard kit, optimally fitting 3–5 people.

Best for: modern aesthetic builds, STR properties where photography matters, or buyers who prefer cedar's characteristics over spruce.

Sauna Type Comparison: Which Is Right for You?

Key Buying Factors: What Actually Matters

Wood Type

This is the factor most buyers underestimate. 70mm Nordic Spruce — the same material used in our cabin kits — has exceptional thermal mass. Thicker walls hold heat longer, heat more evenly, and use less energy per session. Cedar is lighter, resists moisture and insects naturally, and has a distinctive scent that many buyers love. Neither is objectively "better" — it's a matter of priorities. Spruce for performance and durability; cedar for aroma and moisture resistance.

Heater Type

Our sauna kits are heater-agnostic — you source the heater separately, which means you can choose what fits your site. Electric heaters are the most common choice: easy to install, controllable via timer or app, and available from most HVAC suppliers. Wood-burning heaters (kiuas) are the traditional choice — they heat more slowly but create a more authentic sauna experience and work off-grid. If you're building at a remote site without reliable electricity, wood-burning is the practical answer.

Foundation and Drainage

An outdoor sauna needs a level, stable base and good drainage. A gravel pad (4" compacted gravel) is the simplest option and works well in most climates. A small concrete pad is more durable. The sauna floor needs to drain — either through a sloped exterior drain or a small drain through the floor. Make sure water from löyly (steam) and post-session rinses can exit cleanly. Poor drainage is the primary cause of premature wood rot in outdoor saunas.

The foundation principles are the same as for cabin kits — read our foundation guide for the full rundown on options and costs.

Pairing a Sauna With Your Cabin Build

Saunas pair best with larger cabin builds and STR properties. Here's the common upgrade path we see:

• 3-Bedroom + Sauna: The most popular STR configuration in mountain markets. The cabin sleeps 6–8, the sauna becomes the headline amenity that justifies premium nightly rates. Total kit investment: $79,000 + $7,500–$8,500.
• Bunkhouse + Sauna: A standalone sleeping structure combined with a sauna — excellent for hunting camps, group retreats, and off-grid properties where the sauna serves as the wellness and gathering space.
• 4–5 Bed Resort Build: At this scale, a sauna is nearly required to compete in STR markets. Pair it with the Porch & Deck Kit for a complete outdoor living experience that commands top-tier nightly rates.

Airbnb ROI: What a Sauna Actually Adds

The data on sauna add-ons for STR properties is compelling. In competitive mountain markets:

• Properties with saunas command an average $30–$60/night premium over comparable listings without one
• Occupancy improvement of 5–10 percentage points is common — guests filter specifically for sauna availability in high-wellness markets
• A $7,500 sauna kit at $40/night premium pays for itself in approximately 188 nights of incremental revenue — roughly 18–24 months of normal operation
• The premium is sticky — guests expect and search for the amenity, making it a durable competitive advantage rather than a temporary novelty

For the full payback period calculation on the cabin + sauna combination, see our Airbnb ROI calculator post. For help sizing the right cabin to pair with, see our cabin kit size guide.

What's Included in a Fireside Sauna Kit — and What You Source

What's Included

• All pre-cut, pre-labeled wall, roof, and floor components
• Door and window units
• Interior bench framework and slats
• Full assembly drawings and instructions
• Hardware package — all fasteners, connectors, and seals

What You Source Separately

• Heater (electric or wood-burning) — typically $400–$1,500 depending on size and brand
• Electrical wiring and panel connection — requires a licensed electrician for most permits
• Foundation / base — gravel pad, concrete pad, or timber beams
• Drain system — exterior drain, interior floor drain, or both
• Optional: lighting, cold plunge integration, exterior lighting, ventilation fan

Total all-in cost for a fully installed outdoor sauna — kit plus heater, electrical, and base — typically runs $9,500–$13,000 for the Backyard Sauna Kit and $10,500–$14,000 for the Square Cedar, depending on your location and labor rates.

Questions about financing the sauna alongside a cabin kit? Our financing page covers loan options and terms — both products can typically be financed together.