Carbon Smart™ Indoor Sauna Room Kit | 6' x 8' x 8' | Thermo Poplar

The Carbon Smart™ Indoor Sauna Room Kit by Finnish Sauna Builders turns a 6' x 8' room with an 8' ceiling into an authentic Finnish sauna — wall and ceiling paneling, benches, an all-glass door, flooring and finishing accessories, all in thermally modified Thermo Poplar. Choose an optional bench accessory package and a heater sized for this room to complete your configuration.

Key Features

• Cut to Order for 6' x 8' x 8': Wall, ceiling and bench components are sized for this room, not a generic fit.
• Thermo Poplar Throughout: Walls, ceiling, benches, moldings and duckboard flooring.
• Clear 1×4 Benching: 20" deep bench boards with supports, built to the configuration you choose.
• All-Glass Sauna Door: Included with every configuration, with wood handles and trim.
• Optional Accessory Packages: Bench Skirting, LED Under Bench Lighting, or the Luxury Package (both).
• Room-Matched Heater Options: 8 kW heaters paired to this room size, or "No Heater" to supply your own.

Thermo Poplar Wood

Carbon Smart™ saunas are made exclusively in Thermo Poplar, thermally modified at approximately 374°F. The chemical-free process improves dimensional stability and resistance to humidity and temperature swings and gives the wood a warm, even tone. It is responsibly sourced to support carbon-smart forestry practices.

Thermo Poplar (only wood option)

Thermally modified poplar with a warm, even brown tone. Used for the walls, ceiling, benches, moldings and duckboard flooring.

Heater Options

These are the heaters Finnish Sauna Builders pairs with a 6' x 8' x 8' room (about 384 cubic feet). Heater sizing accounts for the all-glass door: glass loses heat faster than an insulated wall, so a room with a glass door needs more heater output than its cubic footage alone suggests.

No Heater

The kit without a heater, for buyers supplying their own heater sized for this room.

Harvia KIP80B 8KW with Built-in Control and Heater Stones

8 kW Harvia KIP with controls built into the heater (no WiFi). Heater stones included.

Harvia Cilindro PC80 8KW with Built-in Control and Heater Stones

8 kW Harvia Cilindro pillar heater with built-in controls (no WiFi). Heater stones included.

Harvia KIP80W 8KW WiFi with Heater Stones

8 kW Harvia KIP with WiFi control for app-based scheduling. Heater stones included.

Harvia Cilindro PC80E 8KW WiFi with Heater Stones

8 kW Harvia Cilindro pillar heater with WiFi control for app-based scheduling. Heater stones included.

Harvia Spirit 8KW WiFi with Heater Stones

8 kW Harvia Spirit with WiFi control for app-based scheduling. Heater stones included.

Harvia Virta 8KW WiFi with Heater Stones and Railing

8 kW Harvia Virta floor-standing heater with WiFi control. Heater stones and a protective railing included.

Choose your accessory package and heater using the option selectors above. Pricing varies by configuration.

Accessory Packages

No Accessories

The complete kit as listed under What's Included, with open bench fronts.

Bench Skirting

Thermo Poplar boards that close in the front of the benches for a finished, built-in look.

LED Under Bench Lighting

Soft LED lighting installed beneath the benches. Supplier photo shows an example installation; room wood in the photo may differ.

Luxury Package: Skirting + LED Under Bench Lighting

Both upgrades together: closed bench fronts plus under-bench LED lighting. Supplier example photo shown.

Specifications

• Brand: Finnish Sauna Builders
• Product Line: Carbon Smart™
• Product Type: Custom-cut (pre-cut) indoor sauna room kit
• Room Size: 6' x 8' footprint, 8' ceiling
• Room Volume: Approximately 384 cubic feet
• Heater Options for This Size: 8 kW (or No Heater)
• Wood: Thermo Poplar (thermally modified)
• Wall & Ceiling Boards: 1×4 tongue & groove
• Bench Boards: Clear 1×4, 20" deep, with supports
• Door Frame: 27.2" × 78.7" (690 × 2000 mm)
• Door Glass: 24.4" × 77.3" (620 × 1963 mm)
• Door Frame Thickness: 1.65" × 3.6" (42 × 92 mm)
• Rough Opening Required: 28" × 80"
• Recommended Ceiling Height: 8' (per manufacturer safety and clearance guidelines)

What's Included

• Foil vapor barrier for moisture protection
• 1×4 tongue & groove boards for walls and ceiling in Thermo Poplar
• Clear 1×4 bench boards with supports (20" deep) in Thermo Poplar, built to your chosen configuration
• Ergonomic backrests and headrest
• Corner moldings for walls, ceiling and baseboards (Thermo Poplar)
• All-glass sauna door with wood handles and trim
• Duckboard flooring for the walk area (Thermo Poplar)
• Upper and lower vent grills for air circulation
• Traditional sauna bucket with liner and ladle
• Sauna thermometer
• Marine-grade, wall-mount, vapor-proof sauna light
• Detailed installation instructions
• Heater package and accessory package, if selected

Wall framing, insulation, electrical wiring, exterior wall covering, and items shown in lifestyle images are not included unless listed above.

Installation & Placement

1. Frame, insulate, wire and cover the exterior of your 6' x 8' room with an 8' ceiling before the kit arrives.
2. Install the foil vapor barrier, then the tongue & groove wall and ceiling boards.
3. Build the bench configuration you selected, including skirting or LED lighting if ordered.
4. Install the all-glass door (28" × 80" rough opening), corner moldings and duckboard flooring.
5. Mount the vent grills and sauna light, then install the heater per its included manual. Heater wiring should be completed by a licensed electrician in line with local codes.

Shipping & Delivery

Shipping Cost: LTL freight shipping on the sauna kit is free. If you add a heater package, heater shipping is calculated at checkout based on the heater's weight. Ships within the contiguous United States only.

Production & Lead Time: Each kit is made on demand after your order and specifications are confirmed and ships out in approximately 20–30 business days. Your estimated lead time is confirmed by email after the order is placed.

Freight Delivery: The kit ships as a crate by LTL freight. The carrier calls to schedule a delivery appointment, and delivery is curbside with liftgate service. Crates longer than 92" may not fit a standard liftgate and may need to be unloaded by hand (two or more people) or with equipment. Missed appointments can incur storage fees.

Inspection: Count the pieces against the bill of lading and note any visible damage on the delivery receipt before signing. Report concealed damage or missing parts to Prime Regeneration within 72 hours of delivery, with photos.

Warranty

This kit includes a Finnish Sauna Builders manufacturer warranty, subject to the manufacturer's written terms, exclusions and claim procedures. Heaters are covered separately by their manufacturer's warranty. Contact Prime Regeneration before purchasing if specific warranty terms are important to your decision.

Returns & Cancellations

Because this kit is custom-cut to order, the manufacturer's made-to-order terms apply in place of our standard 30-day return window:

• Cancellations within 24 hours of purchase are eligible for a full refund.
• Cancellations after 24 hours are subject to the manufacturer's restocking fee, typically 35% of the purchase price.
• Orders cannot be canceled once shipped, and custom-cut kits cannot be returned.

Important Wellness Information

Sauna bathing is not suitable for everyone. Consult your physician before use if you are pregnant, have a medical condition, or take medication. Stay hydrated, keep sessions moderate, leave the sauna if you feel unwell, avoid alcohol before or during use, and supervise children at all times. This product is not intended to diagnose, treat, cure, or prevent any disease.

FAQ

Do I need to buy a heater with this kit?
No. Select "No Heater" if you're supplying your own, or choose one of the heater packages matched to a 6' x 8' x 8' room.

What do I need to provide?
Framing, insulation, electrical wiring and the exterior wall covering. The kit supplies the interior paneling, benches, door, flooring, vents, light and accessories.

What ceiling height does this kit require?
An 8-foot ceiling is recommended per manufacturer safety and clearance guidelines. Contact our team about custom ceiling heights.

Is shipping free?
Yes, shipping on the sauna kit itself is free. If you choose a heater package, heater shipping is calculated at checkout based on the heater's weight.

Manuals & Documentation

Review the installation instructions before framing your room, and the manual for the heater or accessory option you choose. A printed copy of the installation instructions ships with your kit.

• Sauna pre-cut kit installation instructions
• Harvia KIP heater installation manual
• Harvia Cilindro heater manual (built-in control models)
• Harvia Cilindro E heater manual (WiFi models)
• Harvia Spirit heater manual (6 kW and 8 kW)
• Harvia Virta heater manual
• LED strip light kit instructions (LED Under Bench Lighting option)