Thermory 4 Person Square Sauna No 42 DIY Kit with Terrace and Window

Thermory 4 Person Square Sauna No 42 DIY Kit with Terrace and Window

Wood Finish and ConfigurationThermo Spruce — Sauna Solo

Heater Bundles

Add-on

$8,619.00

Shipping calculated at checkout.

4 Person Square Sauna No 42 DIY Kit with Terrace and Window

The 4 Person Square Sauna No 42 DIY Kit with Terrace and Window is a 3–4 person square sauna DIY kit built from thermally-modified Northern European Spruce — chemical-free, kiln-stable, and engineered to outlast cedar in any climate. Pre-cut and pre-milled with no on-site cutting required, you'll install it in about a day with no specialty tools.

Configure your build below: pick a structural Configuration (Sauna Solo or with add-on kits), choose your heater package (Harvia or Homecraft, or bring your own), and add lighting or accessory packages.

Key Features

Capacity	3–4 Person
Configuration	Terrace + Wide Rear Window
Benches	Lower: 6.5 ft × 1.61 ft · Upper: 2.9 ft × 1.61 ft
Door	6'2" tempered-glass entry door
Wood	Thermally Modified Northern European Spruce (chemical-free heat & steam treatment)
Installation	DIY-friendly · pre-cut and pre-milled · no on-site cutting · ~1 day install

Dimensions

Outside	6.90 ft L × 6.90 ft W × 7.28 ft H
Inside	191 cu ft
Interior Volume	191 cu ft

Choose Your Heater

Pick from authorized Harvia (Finland) or Homecraft (USA) heater packages. All Homecraft packages include the Outdoor Wifi Touchpad and stones. Harvia packages with Fenix Control add a separate Wi-Fi-enabled touch panel.

8 kW Harvia KIP B

Mechanical dial control · Stainless steel cabinet
240V 1-Phase · Made in Finland

8 kW Harvia KIP W + Stones

Xenio Smart Wi-Fi touch panel · Stainless steel
240V or 208V · Made in Finland

8 kW Harvia Spirit + Stones

Premium wall-mount · Xenio + Fenix Wi-Fi control
Stones + Fenix touchscreen included · Made in Finland

6 kW Homecraft Revive Slim

Slim-profile electric · Outdoor Wi-Fi touchpad included
Back baffle · Stones included · 240V · Made in USA

Add-on Modifiers

Stack any add-on with your chosen Configuration and Heater bundle — picked separately so you only pay for what you want.

Under-Bench Lighting (+$689) — Warm LED strip lighting concealed beneath the lower bench. Sauna-rated, low-voltage, with dimmer.
Bucket, Ladle & Thermometer Package (+$298) — Finnish hardwood bucket with PVC liner, matching ladle, and a sauna-rated thermometer/hygrometer combo. Ready to use on day one.

Why Thermory

Thermory is the only thermally-modified barrel sauna manufacturer in North America. We heat and steam our Nordic spruce to chemically alter the wood at the cellular level — releasing sugars that attract rot, stabilizing the cell walls against moisture, and locking in dimensional stability that cedar can't match. Result: a sauna that doesn't shrink or warp through changing seasons and outperforms competitors on durability, rot-resistance, and clean aesthetic. No chemicals. No sealers required. Just wood, perfected.