Carbon Smart 8' x 9' x 8' Indoor Sauna Room

The Carbon Smart Indoor Sauna Room turns a spare room, basement, or garage into an authentic Finnish-style sauna. Every interior component arrives pre-cut in Premium Thermo Poplar, a chemical-free thermally modified wood that resists heat, humidity, and warping for years of daily use.

• Indoor Sauna Kit
• Premium Thermo Poplar
• Pre-Cut to Fit
• DIY or Pro Install

A complete indoor sauna kit, cut to your room

The Carbon Smart room kit gives you every surface that makes a sauna a sauna: the wall and ceiling boards, the benches, the door, the trim, the floor, and the ventilation. It all arrives pre-cut in Premium Thermo Poplar to fit a 8' x 9' room. You handle the shell (framing, insulation, wiring, and exterior wall covering) and we handle the interior, so the finished result looks and performs like a custom-built sauna without the custom price.

Why the Carbon Smart room kit works

• Pre-cut interior, ready to assemble. Wall and ceiling boards, benches, moldings, and trim arrive cut to your room footprint. No guesswork, no waste, just assembly.
• Premium Thermo Poplar. Thermally modified at roughly 374°F through a chemical-free process. It resists humidity swings, stays dimensionally stable, runs cooler to the touch than dark hardwoods, and keeps a warm, even tone.
• Custom bench configurations. Choose the bench layout that fits how you want to sit, lie down, or seat a group.
• All-glass door included. A frameless glass door with wood handles and trim, the centerpiece look of a modern sauna.
• Flexible Harvia heater selection. Pick from four WiFi-controlled Harvia heaters from 10kW to 11kW, or order without a heater if you are supplying your own.
• Built for home or commercial use. The same kit suits a personal basement sauna or a spa and gym fit-out.

Specifications

What is in the box

Always included

• Foil vapor barrier for moisture protection
• 1x4 tongue and groove wall and ceiling boards in Thermo Poplar
• Clear 1x4 bench boards with supports, 20″ deep, in Thermo Poplar, cut to your chosen configuration
• Ergonomic backrests and a comfortable headrest
• Corner moldings for walls, ceiling, and baseboards in Thermo Poplar
• All-glass sauna door with wood handles and trim
• Duckboard flooring for the walk area in Thermo Poplar
• Upper and lower vent grills for air circulation
• Traditional sauna bucket with liner and ladle
• Sauna thermometer
• Marine-grade, vapor-proof, wall-mounted sauna light
• Detailed installation instructions

Included only if selected

• Harvia 8kW electric heater
• Sauna stones, included with every heater selection
• Safety railing, included with the Harvia Virta heater only
• Bench skirting, with the Bench Skirting or Luxury package
• LED under-bench lighting, with the LED or Luxury package

Not in the box, you supply

• Wall framing and insulation
• Electrical wiring and the 240V hookup
• Exterior wall covering
• Foundation or flooring outside the duckboard walk area

Choose your heater

• No heater. Choose this if you are supplying your own compatible sauna heater. Heater and sauna stones are not included with this selection.
• Harvia Cilindro 11kW WiFi. Tall cylindrical heater with large stone capacity and the highest output in this lineup, with WiFi app control.
• Harvia Club 10kW WiFi. Floor-standing, commercial-grade heater built for heavy-duty use, with WiFi app control.
• Harvia Virta 10.5kW WiFi. Premium wall-mounted heater with WiFi control and an included protective safety railing.
• Harvia Virta Combi 10.5kW WiFi. Premium heater with WiFi control, a safety railing, and a built-in steam generator for combined sauna and steam.

Accessory packages

• Bench Skirting. Closes the open space beneath the bench for a clean, finished, built-in look.
• LED Under Bench Lighting. A soft warm glow beneath the bench for a relaxing ambiance.
• Luxury Package. Both upgrades together: bench skirting plus LED under-bench lighting.

Why Thermo Poplar

Thermo Poplar is heat-treated at around 374°F in a chemical-free process. The heat drives out moisture and natural sugars, so the wood resists humidity swings, stays dimensionally stable, and will not leach resin the way untreated softwoods can. It runs cooler against bare skin than dark hardwoods, holds a warm even tone, and stands up to years of high-heat sauna cycles.

Installation and site prep

Start with a framed, insulated room that has the correct rough opening for the glass door and a dedicated 240V line if you are using an electric heater. The kit supplies all interior surfaces, the door, the ventilation grills, and the trim, pre-cut to your 8' x 9' footprint. Most rooms are completed by a confident DIYer or a contractor. Wall boards run horizontally unless the room width exceeds 8 ft, in which case an interior seam is added where two boards meet.