The Carbon Smart™ Indoor Sauna Kit gives you everything you need to build a finished, full-size home sauna — precisely cut interior components, sustainably sourced Thermo Poplar wood, and a complete accessory package ready for installation. This 6’ × 7’ × 8’ kit is well-suited for dedicated sauna rooms in basements, spare rooms, or additions, and can be assembled by a capable DIYer or a professional contractor. Optional 8KW Harvia heater upgrades and accessory packages let you configure the kit to match your space and preferences.
Why Customers Choose This Kit
- Complete interior package — walls, ceiling, benches, door, flooring, vents, and accessories all included
- Thermo Poplar wood is thermally modified without chemicals for lasting stability in high-heat, high-humidity environments
- Customizable bench configurations to fit your layout and seating preferences
- Six optional 8KW Harvia heater upgrades — choose built-in control or WiFi-enabled models
- Optional accessory packages: bench skirting, LED under-bench lighting, or the full luxury bundle
- Detailed installation instructions included — designed for DIY assembly or professional installation
- Backed by Finnish Sauna Builders, a specialist supplier with deep expertise in sauna construction
Product Highlights
Thermo Poplar Interior Wood
All wall boards, ceiling boards, bench boards, and trim are crafted from Thermo Poplar — a sustainably sourced wood thermally modified at approximately 374°F. The process enhances dimensional stability and resistance to humidity without the use of chemicals, producing a warm, rich tone suited to sauna interiors.
All-Glass Sauna Door
The kit includes a full all-glass door with wood handles and trim. Frame dimensions are 27.2” × 78.7” (690 × 2000 mm); glass panel is 24.4” × 77.3” (620 × 1963 mm). Rough opening required: 28” × 80”.
Customizable Bench Layout
Select the bench configuration that best fits your space from the options shown in the product images. Bench boards are 20” deep, built to your chosen layout, and include supports. Backrests ship flat; angled positioning can be achieved on-site with simple spacers.
Optional 8KW Harvia Heater Upgrades
Choose from six Harvia heater options — KIP80B (built-in control), Cilindro PC80 (built-in control), KIP80W (WiFi), Cilindro PC80E (WiFi), Spirit (WiFi), or Virta (WiFi + safety railing). All heater options include heater stones. See the comparison chart below for full details.
Foil Vapor Barrier Included
A foil vapor barrier is included in every kit to support proper moisture management during installation. You supply the framing, insulation, electrical wiring, and exterior wall covering.
Marine-Grade Vapor-Proof Lighting
Every kit includes a wall-mount, marine-grade, vapor-proof sauna light rated for the high-humidity sauna environment.
What’s Included in Your Kit
- Foil vapor barrier
- 1×4 tongue & groove wall and ceiling boards — Thermo Poplar
- Clear 1×4 bench boards with supports (20” deep) — custom-built to your chosen configuration
- Ergonomic backrests
- 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
Specifications
| Interior Dimensions | 6’ × 7’ × 8’ (W × D × H) |
| Recommended Ceiling Height | 8 feet (per manufacturer safety guidelines) |
| Wood Species | Thermo Poplar (thermally modified, chemical-free) |
| Wall & Ceiling Boards | 1×4 tongue & groove |
| Bench Depth | 20 inches |
| 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” |
| Optional Heater Power | 8 KW (all Harvia heater options) |
| Optional Heater Brand | Harvia (Finland) |
| Shipping Weight (approx.) | 800 lbs |
| Wood Modification Temperature | Approx. 374°F (thermally modified) |
| Forestry Sourcing | Sustainably sourced, carbon-smart forestry practices |
Ideal For
- Homeowners building a dedicated sauna room in a basement, spare room, or addition
- DIY builders comfortable with framing, insulation, and basic electrical rough-in
- Contractors and builders sourcing premium sauna interior packages for clients
- Residential wellness spaces, home gyms, and spa-style retreats
- Commercial installations in boutique fitness studios, spas, or wellness facilities
Important Information
- This kit supplies all interior sauna components. Framing, insulation, electrical wiring, and exterior wall covering are not included and must be supplied by the installer.
- Recommended ceiling height is 8 feet per manufacturer safety and clearance guidelines. For custom ceiling heights, contact our support team before ordering.
- Wall boards run in the standard horizontal direction. If room width exceeds 8 feet, an interior seam will be added where two boards meet to span the full width.
- Backrests ship flat. Angled positioning can be achieved on-site using simple spacers.
- Your shipment includes an all-glass door. Some product photos may show a glass wall panel for reference purposes.
- Heater installation requires a licensed electrician. All electrical work must comply with local building codes and the heater manufacturer’s installation specifications.
- This product is intended for indoor residential or commercial use only. Do not install in outdoor or unenclosed environments.
- Review all local building permits and requirements before beginning installation.
Optional Heater Comparison
| Feature | Harvia KIP80B 8KW | Harvia Cilindro PC80 8KW | Harvia KIP80W 8KW | Harvia Cilindro PC80E 8KW | Harvia Spirit 8KW | Harvia Virta 8KW |
|---|---|---|---|---|---|---|
| Product Image |  |
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| Power Output | 8 KW | 8 KW | 8 KW | 8 KW | 8 KW | 8 KW |
| Brand | Harvia | Harvia | Harvia | Harvia | Harvia | Harvia |
| Control Type | Built-in panel | Built-in panel | WiFi control | WiFi control | WiFi control | WiFi control |
| WiFi / App Control | No | No | Yes | Yes | Yes | Yes |
| Heater Stones Included | Yes | Yes | Yes | Yes | Yes | Yes |
| Safety Railing Included | No | No | No | No | No | Yes |
| Model Series | KIP | Cilindro | KIP | Cilindro | Spirit | Virta |
Harvia KIP80B 8KW
Harvia Cilindro PC80 8KW
Harvia KIP80W 8KW WiFi
Harvia Cilindro PC80E 8KW WiFi
Harvia Spirit 8KW WiFi
Harvia Virta 8KW WiFi + Railing
Frequently Asked Questions
What does this kit include?
The kit includes all interior sauna components: foil vapor barrier, 1×4 tongue & groove wall and ceiling boards, bench boards with supports, ergonomic backrests, 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 detailed installation instructions. Framing, insulation, electrical wiring, and exterior wall covering are not included.
What do I need to supply for installation?
You supply the structural framing, insulation, electrical wiring (including a dedicated circuit for the heater if selected), and exterior wall covering. A licensed electrician is required for heater installation. All work must comply with local building codes.
What is Thermo Poplar and why is it used?
Thermo Poplar is a sustainably sourced wood thermally modified at approximately 374°F using a chemical-free process. This treatment improves dimensional stability and resistance to humidity and temperature fluctuations — important properties in a sauna environment. It also produces a warm, rich tone suited to sauna interiors.
Can I choose a different ceiling height?
The recommended ceiling height is 8 feet per manufacturer safety and clearance guidelines. If you need a custom ceiling height, please contact our support team before placing your order so we can advise on feasibility and any adjustments required.
What heater options are available?
Six 8KW Harvia heater options are available: KIP80B (built-in control), Cilindro PC80 (built-in control), KIP80W (WiFi), Cilindro PC80E (WiFi), Spirit (WiFi), and Virta (WiFi + safety railing included). All heater options include heater stones. You can also select “No Heater” if you plan to source a heater separately.
What is the difference between the KIP and Cilindro heater series?
The KIP series features a compact wall-mounted design, available in built-in control (KIP80B) and WiFi (KIP80W) versions. The Cilindro series has an iconic cylindrical form with a larger stone capacity, available in built-in control (PC80) and WiFi (PC80E) versions. Both series are 8KW and made by Harvia in Finland.
What accessory packages are available?
Three accessory packages are available: Bench Skirting (adds a finished panel below the bench), LED Under Bench Lighting (adds low-profile lighting beneath the bench), and the Luxury Package which includes both skirting and LED lighting. You can also select “No Accessories” for the standard configuration.
How are the wall boards oriented?
Wall boards run in the standard horizontal direction. If the room width exceeds 8 feet, an interior seam will be added where two boards meet to span the full width. This is a standard construction detail and does not affect the structural integrity or appearance of the finished sauna.
What is the rough opening required for the door?
The rough opening required for the included all-glass door is 28” × 80”. The door frame dimensions are 27.2” × 78.7” (690 × 2000 mm) and the glass panel is 24.4” × 77.3” (620 × 1963 mm).
Is this kit suitable for commercial use?
Yes. The Carbon Smart™ kit is suitable for both residential and commercial installations, including boutique fitness studios, spas, and wellness facilities. For commercial projects or multi-unit orders, contact our team for guidance on specifications and lead times.
The Carbon Smart™ Indoor Sauna Kit is a complete, well-specified package for anyone ready to add a permanent sauna to their home or facility. Select your accessory package and heater option above, and contact our team if you have questions about your space or installation requirements before ordering.
This product is a sauna construction kit intended for personal or commercial use. It is not a medical device and is not intended to diagnose, treat, cure, or prevent any disease or health condition. Consult a qualified healthcare provider before use if you have any medical concerns.