Thermally modified wood
A solid Nordic spruce shell brings the warmth and texture of real wood, with improved stability and decay resistance for outdoor use.
A small sauna with a daily place in your life.
A quiet session on your own, or a close seat beside someone you know. The No. 45 brings Thermory’s rounded Square design to a compact outdoor space.
Its glass front, solid rear wall and compact bench arrangement make it a sitting sauna for one or two. For a long reclining bench, L-shaped group seating and porch seats, choose the Medium or Large.
Thermory quality, board by board.
At Thermory’s plants in Estonia, every board is scanned and graded on the line, so only the best wood ends up in your sauna.
Thermal modification is a controlled process: heat and steam, with schedules matched to the wood species and sensors monitoring the kiln. It improves dimensional stability and decay resistance without chemical preservatives.
That is why the Thermory name matters to us. The material, the milling and the quality checks all contribute to how the kit goes together and how the wood handles repeated heat, moisture and outdoor weather.
Explore Thermory at Sauna Marketplace
Made for the backyard. Built with care.
The rain jacket is included
The fitted roof cover protects the top of the sauna in wet weather. Install its securing slats as the manual shows and keep the cover in good condition.
The details still matter
A level base, correctly fitted glass, ventilation, band tension and drying after use all matter. We help you plan the build and care for the sauna afterward.
Check the fit.
| Exterior (W × D × H) | 52.76″ × 57.09″ × 87.00″ |
|---|---|
| Interior (W × D × H) | 47.64″ × 44.09″ × 76.77″ |
| Door (W × H) | 24.41″ × 73.03″ |
| Occupancy | 1–2 people |
| Shell material | Thermally modified Nordic spruce |
| Wall / board thickness | 1.57″ (manufacturer specification) |
| Nominal volume | 98 cu. ft. (manufacturer specification) |
| Front / rear | Glass front with door / solid wooden rear wall |
| Porch | No porch |
Dimensions follow . Thermory describes the drawing’s measurements as rounded, informative values.
Choose the heat for this smaller room.
Thermory lists the Homecraft Revive Slim 5 kW with a TKE2-2 indoor/outdoor control for the No. 45. Choose the package in the product options to see what it includes.
Heater placement, clearances, ventilation and electrical work must follow the selected heater’s installation instructions. The Revive Slim manual specifies 42″ above a 36″ heater (78″ total), while the No. 45 drawing lists 76.77″ inside; the shielded Thermory package needs its applicable installation instructions confirmed before installation.
What arrives with your sauna.
Assembly guide; two cradles; center, body and roof-closing staves; rear wall panels; glass front panels; door, handle and moldings; wooden trims; rear and side benches with supports; backrest; floor grids and movable step bench; metal bands; seals, fasteners and assembly accessories; rain jacket and securing slats. See the exact-model parts list for the complete inventory.
The heater, controls and stones are separate. The selected heater package lists its contents. Plan for a foundation, assembly and electrical installation at your site.
The first Square in North America became our test bench.
Experience from the first one
Ben Frizzell owns the first Thermory Square sent to North America. He built his No. 40 near Bend, Oregon. We have used that sauna to learn about heater placement, ventilation and bench layouts: the details that change the experience once you sit down.
Ask us where your feet will rest, how the heater occupies the room, or what to prepare before delivery.
This is our older Large No. 40, with some preassembled panels. Current kits use individual staves. The Medium and Small have their own dimensions and assembly instructions; follow the manual for the kit you order.
Talk through your Square with a BenWatch the No. 45 assembly.
The kit includes pre-cut, pre-milled wooden components and an assembly guide. Thermory recommends two people; assembly typically takes about a day, depending on experience. Electrical installation requires a qualified electrician.
Install the sauna on a stable, level base that supports its weight, with the cradles raised clear of wet ground and space for maintenance. Follow the guide for wood treatment, roof-cover fitting, band tightening and snow removal.
The No. 45 guide shows a low ventilation opening through the rear panel, covered by an exterior grille. It does not show a wall duct rising to a high outlet. Additional ventilation requirements depend on the selected heater.
Your questions, answered.
Can I lie down in the Small Square?
The Small is a compact sitting sauna. Choose the Medium or Large for a 6 ft 6 in rear bench and more room to stretch out.
Does it have the same L-shaped layout and porch?
No. The No. 45 has its own compact rear-seat and side-bench arrangement, and no porch. The Medium and Large have L-shaped upper seating, lower footrests and two porch seats.
Is the rain jacket included?
Yes. The kit includes the rain jacket and securing slats. Follow the assembly guide when fitting it and check its condition as part of routine care.
Does the price include the heater and electrical work?
The starting price is the sauna kit, before the heater package and shipping. You build the heater package that suits you; electrical supply and installation are work for your qualified electrician.
What warranty and delivery should I plan for?
Thermory provides a two-year limited warranty for the initial buyer, subject to its warranty terms and exclusions. Heaters, electrical components and glass are excluded from that Thermory warranty; their applicable coverage is separate.
Sauna Marketplace ships this kit by palletized LTL freight with curbside lift-gate delivery. Ask about the Sauna Marketplace Builder Network if you would like help arranging assembly.
Will you help after it arrives?
Yes. We help with assembly questions and work with Thermory when a part or product issue needs attention. Bring your questions to a Book a Ben consultation before or after you order.
Your manual and warranty.
Download the No. 45 assembly guide · Thermory Sauna Squares
Thermory provides a two-year limited warranty for the initial buyer, subject to its warranty terms and exclusions. Heaters, electrical components and glass are excluded from that Thermory warranty; their applicable coverage is separate.
Sauna Marketplace ships this kit by palletized LTL freight with curbside lift-gate delivery. Ask about the Sauna Marketplace Builder Network if you would like help arranging assembly.
Compare Thermory Squares
Which Square is yours?
Start with how you want to sit, then choose your rear wall. No. 40 and 41 share the Large layout; No. 42 and 43 share the Medium layout. No. 45 is the compact sitting sauna.
Compare all five models below. Every Square has a glass front and includes the rain jacket.
Matches your choices
No. 40 Large Square
Sauna kit $9,477.00
Panoramic rear glass
More side-bench room for time together.
- Outside · W × D × H
- 82.7 × 98.8 × 87.9 in
- Upper seating
- 78 in rear · 51.2 in side
- Cool-down space
- Two porch seats
- Rear wall
- See the view through both ends.
Matches your choices
No. 41 Large Square
Sauna kit $8,811.00
Solid wood rear wall
More side-bench room for time together.
- Outside · W × D × H
- 82.7 × 98.8 × 87.9 in
- Upper seating
- 78 in rear · 51.2 in side
- Cool-down space
- Two porch seats
- Rear wall
- Glass front, solid wood behind you.
Matches your choices
No. 42 Medium Square
Sauna kit $8,619.00
Panoramic rear glass
The same reclining length with 15.6 in less overall depth.
- Outside · W × D × H
- 82.7 × 83.2 × 87.9 in
- Upper seating
- 78 in rear · 35.4 in side
- Cool-down space
- Two porch seats
- Rear wall
- See the view through both ends.
Matches your choices
No. 43 Medium Square
Sauna kit $8,008.00
Solid wood rear wall
The same reclining length with 15.6 in less overall depth.
- Outside · W × D × H
- 82.7 × 83.2 × 87.9 in
- Upper seating
- 78 in rear · 35.4 in side
- Cool-down space
- Two porch seats
- Rear wall
- Glass front, solid wood behind you.
Matches your choices
No. 45 Small Square
Sauna kit $5,478.00
Solid wood rear wall
A compact sitting sauna for one or two.
- Outside · W × D × H
- 52.76 × 57.09 × 87 in
- Upper seating
- Compact sitting layout
- Cool-down space
- No porch
- Rear wall
- Glass front, solid wood behind you.
Dimensions include the porch where fitted; allow additional room for door swing, assembly, service and required clearances. The 78 in rear bench in the Medium and Large gives one person room to recline; the side bench is additional seating. Prices are for the sauna kit, before the heater package and shipping; you build the package that suits you. Review the package, delivery and tax on its product page.
Prebuilt
Brushes, Whisks and Body Care
Vents