The Carbon Smart™ Indoor Sauna Kit (8' × 8' × 8') is a complete, pre-cut sauna interior package designed for larger sauna rooms. Built with thermally modified Thermo Poplar wood, it delivers lasting dimensional stability, natural moisture resistance, and a refined aesthetic. Select your accessory package and optional high-output Harvia electric heater at checkout, and receive everything needed to finish your sauna interior — precisely cut and ready to install.
Why Customers Choose the Carbon Smart Sauna Kit
- All interior components arrive pre-cut to your 8' × 8' × 8' room dimensions — no guesswork, no waste
- Thermo Poplar wood is thermally modified without chemicals for enhanced stability and humidity resistance
- Responsibly sourced wood supports carbon-smart forestry practices
- All-glass sauna door included — no separate door purchase required
- Optional high-output Harvia heater bundles (10–11 kW) available at checkout for a single-order setup
- All heater options include WiFi app control and sauna stones
- Configurable accessory packages: bench skirting, LED under-bench lighting, or both
- Detailed installation instructions included for DIY and contractor builds
Product Highlights
Thermo Poplar Interior Wood
Thermally modified at approximately 374°F using a chemical-free process, Thermo Poplar offers improved dimensional stability, reduced moisture absorption, and a warm, rich tone that holds up through repeated heat cycles.
Pre-Cut to Your Room Dimensions
Wall boards, ceiling boards, bench boards, and trim pieces are cut to fit your 8' × 8' × 8' room before shipping, reducing installation time and on-site cutting.
All-Glass Sauna Door Included
The kit includes a full all-glass door with wood handles and trim. The rough opening required is 28" × 80", and the frame measures 27.2" × 78.7" (690 × 2000 mm).
Configurable Accessory Packages
Select from No Accessories, Bench Skirting, LED Under-Bench Lighting, or the Luxury Package (Skirting + LED Lighting) to match your finish preferences and budget.
High-Output Harvia Heater Options (10–11 kW)
Four WiFi-enabled Harvia heater options are available at checkout, ranging from 10 to 11 kW — sized for the larger volume of an 8' × 8' × 8' sauna room. All include sauna stones.
Virta Combi Option: Dry Sauna and Steam in One
The Harvia Virta Combi 10.5 kW adds an integrated steam generator, allowing the sauna to function as both a traditional dry sauna and a steam room from a single unit.
Marine-Grade Vapor-Proof Lighting
A wall-mount, marine-grade, vapor-proof sauna light is included in every kit, rated for the high-humidity sauna environment.
Proper Ventilation Components
Upper and lower vent grills are included to support correct air circulation, an important factor in sauna performance and longevity.
Specifications
| Room Dimensions | 8' × 8' × 8' (W × L × H) |
|---|---|
| Wood Species | Thermo Poplar (thermally modified, chemical-free) |
| Wall & Ceiling Boards | 1×4 tongue & groove, Thermo Poplar |
| Bench Boards | Clear 1×4, 20" deep, Thermo Poplar — custom-cut to configuration |
| Door Frame Size | 27.2" × 78.7" (690 × 2000 mm) |
| Door Glass Size | 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 ft (per manufacturer safety guidelines) |
| Wall Board Direction | Horizontal (standard); interior seam added if room width exceeds 8 ft |
| Accessory Options | No Accessories / Bench Skirting / LED Under-Bench Lighting / Luxury Package |
| Heater Options | No Heater / Harvia Cilindro 11 kW WiFi / Harvia Club 10 kW WiFi / Harvia Virta 10.5 kW WiFi / Harvia Virta Combi 10.5 kW WiFi |
| Shipping Weight | Approx. 800 lbs |
| Vendor | Finnish Sauna Builders |
What's Included in Every Kit
- Foil vapor barrier
- Ergonomic backrests (shipped flat; angled pitch achievable with on-site spacers)
- 1×4 tongue & groove wall and ceiling boards — Thermo Poplar
- Clear 1×4 bench boards with supports (20" deep) — Thermo Poplar, cut to your configuration
- Corner moldings for walls, ceiling, and baseboards — Thermo Poplar
- All-glass sauna door with wood handles and trim
- Duckboard flooring for walk area — Thermo Poplar
- Upper and lower vent grills
- Traditional sauna bucket with liner and ladle
- Sauna thermometer
- Headrest
- Marine-grade, wall-mount, vapor-proof sauna light
- Detailed installation instructions
Note: Framing, insulation, electrical wiring, and exterior wall covering are not included and must be supplied by the installer. Some product photos may show a glass wall for reference; the kit ships with an all-glass door.
Optional Harvia High-Output Heater Comparison
All heater options include WiFi app control and sauna stones. All four models are sized for larger sauna rooms.
| Model | Series | Output | WiFi | Railing | Combi Steam |
|---|---|---|---|---|---|
| Harvia Cilindro 11KW | Cilindro | 11 kW | Yes | No | No |
| Harvia Club 10KW | Club | 10 kW | Yes | No | No |
| Harvia Virta 10.5KW | Virta | 10.5 kW | Yes | Yes | No |
| Harvia Virta Combi 10.5KW | Virta Combi | 10.5 kW | Yes | Yes | Yes |
Ideal For
- Homeowners building a large dedicated indoor sauna room in a basement, addition, or dedicated space
- DIY builders who want pre-cut materials and clear installation instructions
- Contractors sourcing complete sauna interior packages for residential or light commercial clients
- Spas, gyms, and wellness facilities requiring a high-capacity sauna interior
- Buyers who want a combined dry sauna and steam room option (Virta Combi)
Important Information
- This kit supplies interior sauna components only. Framing, insulation, electrical wiring, and exterior wall covering must be provided by the installer.
- Recommended ceiling height is 8 feet per manufacturer safety and clearance guidelines. For custom ceiling heights, contact the vendor before ordering.
- High-output heaters (10–11 kW) require dedicated electrical circuits. Installation must be performed by a licensed electrician in compliance with local building codes and the heater manufacturer's specifications.
- Wall boards run horizontally by default. If room width exceeds 8 feet, an interior seam will be added where boards meet to span the full width.
- Backrests are shipped flat. If an angled backrest is preferred, additional spacers can be fabricated on-site to achieve the desired pitch.
- The kit ships with an all-glass door. Some product images may show a glass wall panel for reference purposes only.
- The Virta Combi steam function requires a water supply connection in addition to electrical installation. Consult the heater manufacturer's installation manual before planning your build.
- Do not use this sauna kit for any purpose other than its intended use as a residential or light commercial sauna interior.
Frequently Asked Questions
What does this kit include?
The kit includes all interior sauna components: foil vapor barrier, tongue & groove wall and ceiling boards, bench boards and supports, corner moldings, an all-glass door with wood handles and trim, duckboard flooring, upper and lower vent grills, a sauna bucket with liner and ladle, a thermometer, a headrest, a marine-grade vapor-proof light, and installation instructions. Framing, insulation, electrical wiring, and exterior wall covering are not included.
Do I need to supply the framing and insulation?
Yes. This kit provides the interior finish components only. You or your contractor will need to supply and install the structural framing, insulation, vapor barrier backing, electrical wiring, and any exterior wall covering before installing the kit components.
What heater options are available for this kit?
Four Harvia WiFi-enabled heater options are available at checkout, all sized for larger sauna rooms: the Cilindro 11 kW, Club 10 kW, Virta 10.5 kW (with railing), and Virta Combi 10.5 kW (with railing and integrated steam function). All include sauna stones. If you prefer to source your own heater, select "No Heater" at checkout.
What is the Virta Combi and how is it different from the Virta?
Both the Virta and Virta Combi are 10.5 kW WiFi-enabled heaters with a protective railing and sauna stones included. The Virta Combi adds an integrated steam generator, allowing the sauna to operate as both a traditional dry sauna and a steam room from a single unit. The Virta Combi also requires a water supply connection in addition to electrical installation.
What is Thermo Poplar and why is it used?
Thermo Poplar is a sustainably sourced wood that has been thermally modified at approximately 374°F using a chemical-free process. This treatment improves the wood's dimensional stability, reduces its tendency to absorb moisture, and gives it a warm, rich tone. It is well-suited for the high-heat, high-humidity environment of an indoor sauna.
What rough opening does the door require?
The included all-glass door requires a rough opening of 28" × 80". The door frame measures 27.2" × 78.7" (690 × 2000 mm) and the glass panel measures 24.4" × 77.3" (620 × 1963 mm). Frame thickness is 1.65" × 3.6" (42 × 92 mm).
What accessory packages are available?
Four accessory options are available at checkout: No Accessories, Bench Skirting, LED Under-Bench Lighting, and the Luxury Package which includes both Bench Skirting and LED Under-Bench Lighting.
Do the high-output heaters require special electrical wiring?
Yes. Heaters in the 10–11 kW range require dedicated electrical circuits and must be installed by a licensed electrician. Electrical requirements vary by model — refer to the specific heater's installation manual for circuit specifications, breaker sizing, and wiring requirements before planning your build.
Is this kit suitable for commercial use?
The Carbon Smart kit is designed for residential use and light commercial applications such as spas and fitness facilities. For high-traffic commercial installations, contact the vendor to confirm suitability and discuss any additional requirements.
The Carbon Smart Indoor Sauna Kit (8' × 8' × 8') gives you a complete, pre-cut interior package built from quality Thermo Poplar wood, with high-output heater options and flexible accessories configurable in a single order. If you have questions about sizing, installation, or heater selection, our team is available to help you plan the right setup for your space.
Sauna use may not be suitable for everyone. Consult a qualified healthcare provider before use if you have a medical condition, are pregnant, or are taking medications. This product is not intended to diagnose, treat, cure, or prevent any disease or medical condition.