The shell
- Footing: concrete deck blocks on compacted base, two or three 4x6 pressure-treated skids, a 2x6 pressure-treated floor at 16 in.
- Walls: 2x6 at 16 in, so the walls take R-23 mineral wool.
- Roof: a 4/12 gable on 2x6 rafters, OSB, synthetic underlayment and metal panels.
- Outside: T1-11 siding, primed and painted.
| Priced in October 2026 | 6 x 7 ft electric | 7 x 8 ft wood-fired |
|---|---|---|
| Site and floor | $706 | $1,053 |
| Framing | $581 | $664 |
| Roof and siding | $1,290 | $1,486 |
| Inside: insulation, foil, boards, benches, door | $3,914 | $4,756 |
| Heater or stove, vents, light | $1,999 | $3,974 |
| Total priced | $8,490 | $11,934 |
Open them: 6 x 7 ft electric, 7 x 8 ft wood-fired.
Power to the cabin
The 8 kW heater in the electric example draws 33.3 A at 240 V. Getting that to a cabin means a feeder from the house panel, usually buried, plus the heater circuit, the light and any outlet. That is the electrician's work and usually needs a permit. Price it before you pick the spot: a long trench costs more than a few feet of cedar.
Where to put it
- Level, well-drained ground, away from overhanging branches if it burns wood.
- Inside your town's setbacks from property lines, and under its size limit for accessory buildings if you want to avoid a building permit.
- Close to the house panel for an electric heater; close to a shower or a cold plunge if you want the contrast.
Footprint of the electric example: 7 ft 2 in x 8 ft 2 in outside the framing.
Questions people ask
Can you build your own outdoor sauna?
Yes. It is a small framed cabin with an insulated, foil-lined room inside. The parts that need a professional are the 240 V heater circuit (a licensed electrician) and, for a wood stove, a listed chimney installed exactly to its manual.
Do you need a permit for a backyard sauna?
Often. A new 240 V circuit usually needs an electrical permit, and many towns want a building permit once an accessory building passes a size limit or has a wood stove. Rules vary by town: call your building department with the footprint before you build.
Do you need a 220 line for a sauna?
For a traditional electric heater, yes: heaters of this size run on 240 V (often called 220). The 8 kW heater in the example draws 33.3 A, on a dedicated circuit a licensed electrician sizes from the manual. A wood stove needs no heater circuit at all.
How much would it cost to build my own outdoor sauna?
At store prices read in October 2026, a 6 x 7 ft electric outdoor sauna comes to about $8,490 in materials and heater, and a 7 x 8 ft wood-fired one to about $11,934, before freight, tax and the electrician. For comparison, the smallest indoor/outdoor kit we found, a 1 to 2 person Sweat Kingdom pod, lists at 5,893 USD without a heater (Haven of Heat, Oct 9, 2026).
How much do home saunas cost to run?
An electric heater uses at most its rating times the hours it is on: the 8 kW heater here running flat out for an hour uses 8 kWh, and it cycles off once the room is hot. Multiply by your electricity rate. Insulation and a ceiling near 84 in keep the bill down.
Electric or wood-fired?
Electric is cleaner to run and easy to time, but needs a 240 V circuit to the cabin. Wood needs no power and gives a softer heat, but needs a listed chimney, clearances to everything that burns, and a stove big enough for the room: the smallest one in our table starts at 212 cu ft.
Sources
Every rule the planner applies comes from the heater maker's own manual or product data where one exists. Where a number is our own default, the designer says so next to it.
- 01HUUMDROP 2.0 electric heater user manual (EU, v6)Room 2000 to 2300 mm high, never under 1900 mm; top bench 1100 to 1300 mm below the ceiling; 50 to 100 mm insulation, foil with taped joints, 10 mm gap behind the boards, 12 to 16 mm boards, 100 mm from the floor; supply air 50 to 100 mm at or below heater mid-height (400 mm), exhaust twice that on the opposite wall at least 200 mm higher (600 mm), drying vent under the ceiling; six air changes an hour; only a certified electrician connects the heater.Read 2026-10-09
- 02HarviaM3 wood-burning heater product dataRoom 212 to 459 cu ft; to combustible material 11.81 in front and rear, 9.84 in each side; minimum room height 6.56 ft.Read 2026-10-09
- 03HarviaPro 20 wood-burning heater product data300 mm (11.81 in) to combustible material front, rear and sides; 1.3 m to the ceiling; minimum room height 2 m.Read 2026-10-09 (search listing)
- 04Haven of HeatHeater listings with the maker's room rangesHarvia KIP 4.5 kW 100 to 210 cu ft, 6 kW 170 to 300, 8 kW 250 to 425; Cilindro 9 kW 141 to 494; Harvia M3 212 to 459; Pro 20 283 to 706.Read 2026-10-09
- 05NFPA 70, National Electrical CodeArticle 424.4(B), branch-circuit sizing for fixed electric space-heating equipment (2020 text)Branch-circuit conductors are sized at no less than 125 percent of the load. Your jurisdiction's adopted edition and the heater's nameplate govern.Read 2026-10-09 (secondary summary)