Short answer: indoors is simpler and cheaper to install. Outdoors frees up a room, but adds a level pad with drainage, usually a 240V circuit run outside by an electrician, and weather you have to manage. If you have a spare corner and a nearby circuit, go indoor. If you have no room inside and a yard you will walk out to in January, go outdoor.
The two cabins we rate, side by side
| Indoor: Clearlight Sanctuary 2 | Outdoor: Sun Home Luminar 2-Person | |
|---|---|---|
| Our rating | Meets the Standard | Meets the Standard |
| Power | 120V, dedicated 20A circuit | 240V, dedicated 20A GFCI circuit, L6-20 twist-lock outlet, licensed electrician |
| Where it sits | Any level indoor floor, with a few inches of clearance if enclosed | A level, load-bearing outdoor surface that drains, so water never pools at the base |
| Weight | 450 lb | 970 lb |
| Weather | None | Rated for year-round use. Works below 25°F but takes longer to warm up. Clear snow from the base and roof; not built to carry more than about a foot |
| Coverage | Lifetime residential on cabin, heaters and electrical | Lifetime on cabinetry and heaters, 3 years on exterior cabin and controls; parts, labor and shipping only in the first 90 days |
From each maker's product page, spec sheet and warranty page, read 2026-10-07 and 2026-10-08.
What going outside adds
- A foundation. A concrete pad or a load-bearing deck, level, with drainage. The Luminar weighs close to half a ton before anyone sits in it.
- An outdoor circuit. 240V, GFCI-protected, run by a licensed electrician. Outdoor electrical work often needs a permit, so check with your city.
- Weather. Snow off the roof, a cover in bad weather, longer warm-up in the cold.
- Rules. Check HOA rules and setbacks before you pour a pad.
- The walk. Every session starts with going outside. For some people that is the point. For others it is why the sauna stops getting used in February.
What staying inside costs you
A room, or a large part of one: the Sanctuary 2 is 52 by 48 inches and 77 inches tall, plus clearance. You also need the path in, since every panel has to fit through the doors on the way. In exchange you skip the pad, the outdoor circuit and the weather.
How to decide
- You have a spare corner, basement or garage bay
- A circuit is close by
- You want the longest coverage we rate
- There is no room inside
- You can pour or build a level, drained pad
- You want sauna and cold plunge together in the yard
Head to head, with prices and the full trade-offs: Clearlight Sanctuary 2 vs Sun Home Luminar.