Finnleo NSI-57 Indoor Sauna

Finnleo NorthStar NSI-57 Indoor Sauna – 5' x 7' Traditional Finnish Sauna

Experience authentic Finnish sauna tradition with the Finnleo NorthStar NSI-57 Indoor Sauna, a spacious 5' x 7' free-standing sauna that delivers big comfort in just 35 sq. ft. of floor space. Proudly made in the USA and hand-crafted in Minnesota, this modular panel-built sauna installs quickly while honoring true Nordic design, materials, and craftsmanship. With an L-shaped top bench, the NSI-57 comfortably seats four to five people, with plenty of room for two to lie down — making it one of Finnleo's most popular indoor sauna models for home wellness, recovery, and relaxation.

Whether you're building a dedicated home spa, upgrading a basement, or creating a private wellness retreat, the NorthStar NSI-57 combines traditional Finnish sauna heritage with modern conveniences like app-based control, color light therapy, and built-in audio — all backed by a name trusted in the sauna industry for decades.

Authentic Nordic Construction

The NorthStar NSI-57 features pre-built Nordic White Spruce interior and exterior walls and ceiling, prized for its light, bright appearance and the natural aromatic character of true Finnish forests. Spruce is a traditional sauna wood valued for its low resin content, dimensional stability under heat, and clean, subtle scent when warmed. As a free-standing, modular panel design, the sauna ships pre-fabricated and is simple to assemble on-site, requiring only a single 240V electrical connection — no additional 120V circuits or complex wiring needed. This construction method allows for fast installation without sacrificing the quality of a true cabin-built sauna.

Premium Bench & Backrest Materials

Benches, backrests, and duckboard flooring are crafted from Aspen or Abachi wood, light-toned hardwoods chosen to maintain the room's bright aesthetic while offering a cooler, more comfortable surface for skin contact during use. The L-shaped bench configuration maximizes seating capacity while preserving open floor space, and the raised duckboard flooring promotes airflow and moisture drainage beneath the benches.

Included Sauna Heater

Every NSI-57 comes standard with a Designer-SL2 6.0 kW sauna heater, sized specifically for this model's cubic footage to deliver fast heat-up times and consistent, even heat distribution. The heater includes a protective heater guard for added safety around benches and backrests, and is fully integrated with the SaunaLogic2® Wi-Fi control system. Every Finnleo heater is safety-tested and certified for use in North America, giving you confidence in both performance and code compliance.

Smart, App-Controlled Experience

The SaunaLogic2® control system lets you manage heat, session time, lighting, and audio remotely through the SaunaLogic2 mobile app. Preheat your sauna before you arrive home, set custom lighting scenes, and monitor your session — all from your smartphone. This connected ecosystem ties the heater, lighting, and sound system into one seamless, app-controlled experience unique to Finnleo saunas.

Ambient Lighting & Audio

Set the mood with in-backrest low-voltage LED lighting featuring a full RGBW color therapy system, creating a warm, customizable glow throughout the cabin for relaxation or chromotherapy sessions. The NSI-57 also includes a built-in Bluetooth sound system, letting you stream music, podcasts, or guided relaxation audio directly inside the sauna for a fully immersive wellness experience.

All-Glass Door & Windows

An all-glass door with sidelight windows enhances visibility and adds a modern, open feel to the sauna's authentic wood interior, blending traditional Finnish design with contemporary style. The glass front also allows natural light to pass through, making the sauna feel larger and more inviting whether installed in a bathroom, basement, or dedicated spa room.

What's Included as Standard

• Nordic White Spruce interior and exterior walls and ceiling
• Designer-SL2 6.0 kW sauna heater with protective heater guard
• Aspen or Abachi benches, backrests, and duckboard flooring
• L-shaped top bench seating 4-5 people
• In-backrest LED RGBW color therapy lighting
• All-glass door and sidelight windows
• Built-in Bluetooth audio sound system
• SaunaLogic2® Wi-Fi control with mobile app
• RENTO Pisara bucket and ladle
• Modular panel construction for fast, straightforward assembly

Specifications at a Glance

• Model: NorthStar NSI-57
• Footprint: 5' x 7' (35 sq. ft.)
• Seating capacity: 4-5 people
• Heater: Designer-SL2, 6.0 kW
• Power requirement: Single 240V connection
• Interior/exterior wood: Nordic White Spruce
• Bench material: Aspen or Abachi
• Control system: SaunaLogic2® Wi-Fi with app control
• Country of origin: Made in the USA (Cokato, Minnesota)

Good to Know

Flooring is not included with the NSI-57 but is available as an optional upgrade for those who want a fully matched, finished look. Seating capacity is rated for 4-5 people, and the sauna requires a single 240V power source for the included heater and controls. As a ready-to-order model, the NSI-57 ships as a complete package with no substitutions, ensuring consistent quality and simplified installation.

Why Choose the NorthStar NSI-57

The NorthStar NSI-57 is built for homeowners who want the genuine sauna experience without a custom-build timeline. It delivers the health and wellness benefits associated with regular sauna use — including improved circulation, muscle recovery, stress relief, and relaxation — in a package that's ready to install in days, not months. The combination of real Nordic White Spruce, a properly sized heater, and smart app control makes it a standout choice among mid-size indoor saunas.

Why Buy Finnleo From Us

Finnleo, built by Sauna360 in Cokato, Minnesota, is one of the most trusted names in authentic Finnish sauna manufacturing. Every Finnleo heater is safety-tested and listed for use in North America, and the SaunaLogic2® ecosystem ties your heater, lighting, and audio into one seamless, app-controlled experience. As an authorized Finnleo dealer, we offer full factory warranty coverage, expert sizing assistance, and dedicated support before and after your purchase. Have a question about fit, voltage, or lead time? Contact us and a sauna specialist will help you spec your NorthStar NSI-57 correctly the first time.