The sauna vs steam room question sounds like a choice between two kinds of heat, but for a home buyer it is mostly a choice between two construction projects. A sauna is a wood room with a heater. A steam room is a sealed, waterproof enclosure with a steam generator feeding it. I don't build either, so what follows is a read-through of maker pages and trade sources, with my arithmetic shown where I add numbers up.
What this guide adds
The pages that rank for this search spend most of their words on how each room feels and on health claims. I read several of them. They give temperature and humidity ranges, and a few give one lump-sum price for the whole job. What I couldn't find in any of them was the buying side laid out line by line: what the heater or generator costs from a maker's listing, what circuit it needs, how big a room it can serve, and what the walls and ceiling have to be. That is the gap I'm filling here, along with a decision rule at the end.
Two limits. I couldn't open every page in the results (Livestrong refused the fetch), and I haven't touched any of this equipment. Everything is "the maker says" or "the page lists."
Sauna vs steam room: temperature and humidity
The two rooms differ most in humidity, and the temperature gap follows from it. Sources agree on the shape and wobble on the edges.
| Item | Traditional sauna | Steam room |
|---|---|---|
| Air temperature | 150–200°F; 160–200°F; 150–195°F; roughly 75–105°C | 110–120°F; 100–120°F; roughly 39–49°C |
| Humidity | Typically 5–20%; 5–30%; rarely above 20%; 10–20% | At or near 100% |
| Warm-up | 30–60 minutes | 10–20 minutes |
One page adds that pouring water on sauna stones pushes humidity to 40–60% for a short while. If you want to see how a sauna's own settings are chosen, my sauna temperature guide goes through them. Infrared cabins sit lower than a traditional sauna, around 120–150°F, and I cover that format in infrared vs traditional sauna.
I don't have a maker explanation for why the sauna runs so much hotter, so I'll just say the sources describe dry air in one room and saturated air in the other, and leave the physics to people who test it.
Room construction: where the two split
A sauna room is wood, usually softwood such as cedar, spruce, aspen or hemlock. It stays dry between uses, so one source says mold and bacteria growth is minimal. You can buy a prefabricated room or a kit and put it in a basement corner or a garage.
A steam room is a different build. A trade article from a tile contractor says the enclosure should be vapor controlled on all sides, ceiling included, and that "the water stops at the waterproofing, not at the tile and grout". Another page says every surface must be completely waterproof, with tile, stone, glass or acrylic as the usual finishes. Mr. Steam's installation guide warns that its steambath system is not for use with acrylic or fiberglass rooms unless you add a separate acrylic shield accessory. Read that twice if you are eyeing a prefab acrylic enclosure.
Then there is the ceiling. Two sources give a slope of 2 inches per foot so condensate runs down the walls instead of dripping on you. The contractor article says the Tile Council of North America recommends 2 inches per foot but that it's "not clear that a slope is required," and that some manufacturers now specify no slope. I'd treat the slope as something to settle with your installer and the generator's manual, not as a fixed rule.
The generator itself lives outside the room. Mr. Steam says to install it within 50 feet of the steam room, never inside it, with at least 12 inches of clearance at both ends and the top. A different page says within 25 feet, so the limit depends on the brand. The contractor article describes a roughly 1 ft by 2 ft footprint needing 1 to 2 feet of height, a safety pan with a drain because these units tend to leak over time, and an auto-drain flush kit where the water is mineral-heavy.
Sizing and circuit: what the machine needs
Here is the part no top result gave me cleanly. A steam generator is sized to the room's volume, and a sauna heater is too, but the numbers aren't comparable.
| Line item | Price | Electrical | Room it serves |
|---|---|---|---|
| Harvia The Wall 6 kW sauna heater | $1,620 | 240V; 25 A on one supply group, 10 AWG wire | 177–294 cu ft |
| Harvia The Wall 8 kW sauna heater | $1,668 | 240V; 33.4 A on one supply group, 8 AWG wire | 177–431 cu ft |
| Mr. Steam MS R 6 kW steam generator | $2,573 | 240V single phase; 30 A breaker, 8 AWG wire | 72–107 adjusted cu ft |
| Amerec AK 4.5 kW steam generator | $1,767.50, control sold separately | 240V or 208V; amps not listed | Up to 90 adjusted cu ft |
Prices come from retailer listings on the day I read them and will drift. The Harvia page lists a 2-year warranty, with a third year if you register within 30 days, and says stones aren't covered.
Two things jump out. First, a 6 kW heater and a 6 kW generator are different animals: the heater listing covers rooms roughly 177–294 cubic feet, while the generator listing covers only up to 107 adjusted cubic feet. "Adjusted" is the makers' term, and I didn't find the formula behind it, so I can't tell you how much tile or glass adds. Ask the maker for a sizing worksheet before you buy.
Second, the circuits are in the same family. One retailer's electrical guide says most home steam generators in the 7.5–10 kW range draw 30 to 45 amps at 240V, and that a 40-amp circuit typically needs 8-gauge copper while a 50-amp circuit needs 6-gauge. If your panel is full, price a new circuit or panel work first. I couldn't source a current dollar figure for either, so get an electrician's quote. For heater picks and wiring details on the sauna side, see my best electric sauna heater page.
What each one costs, in total
Lump-sum figures disagree a lot, which tells you something by itself.
| Sauna | Steam room |
|---|---|
| $2,000–15,000 total; installation $0–3,000 | $10,000–25,000+ total; installation $5,000–15,000+ |
| $3,000–20,000+ (infrared near $3,000; custom traditional $10,000–20,000+) | $5,000–15,000+ |
| $2,900 installed | $3,300 installed |
The Fixr numbers are for a very small footprint and look low next to the other two, and I can't reconcile them. My read is that the steam room range is wider and higher because tile, waterproofing and plumbing labor are in it, while a sauna can be a kit. Haven of Heat puts home steam equipment at $3,000–8,000+ before installation. For a sauna-only breakdown with more line items, see sauna cost.
Running cost is small either way. Leisure Time estimates about $4–6 a month for a traditional sauna and $3–5 a month for a steam generator, plus descaling. My arithmetic, at an illustrative $0.20 per kWh (swap in your rate), assuming the heating element is on the entire time, which overstates it:
- Sauna: 6 kW × 1 hour = 6 kWh × $0.20 = $1.20.
- Steam room: 6 kW × 0.5 hour = 3 kWh × $0.20 = $0.60.
Real units cycle once they reach temperature, so both figures sit above reality. Neither number should drive the decision.
Maintenance, mold and moisture
This is where the steam room asks more of you. One source calls a sauna "remarkably low-maintenance," with stones replaced every few years, and says a steam room needs more vigilance: grout sealing, re-grouting from time to time, and descaling the generator. It adds that a steam room's near-100% humidity suits mold, mildew and bacteria if surfaces aren't cleaned regularly. QuickCrop agrees that saunas are generally lower maintenance.
Ventilation is a trap. The contractor article says showers without fans stay damp and grow mold, yet a fan can cause its own problems, and some generator makers advise against one. Moisture can enter ducts, and steel parts can rust. That is a detail for your installer to resolve with the generator's manual in hand.
Health: what I can and can't say
I'm not a doctor and I won't say which is healthier. Research on both is mixed or limited, and the American Lung Association says little research supports the advantages of saunas and that they aren't right for everyone. It lists children, pregnant people, people with high blood pressure and those with preexisting heart conditions as higher-risk, says the dry air can make breathing harder with lung disease, and tells first-timers to spend no more than 5 to 10 minutes in the heat and nobody more than 20. One steam room source also says humid air and mold can worsen asthma. If any of that applies to you, ask your doctor before you buy, not after.
A decision rule for a home
Start with what your house gives you, not what the rooms feel like.
- If you can't add a 240V circuit or build a sealed enclosure, neither project is cheap, and an indoor sauna kit is the smaller job. My best indoor sauna page covers those.
- If you're remodeling a bathroom anyway and already paying for tile and waterproofing, a shower enclosure you're already waterproofing is the cheapest place to add a generator, since the installation ranges above are mostly tile, plumbing and waterproofing.
- If you hate cleaning grout and descaling, pick the sauna.
- If you want humid, gentler heat and don't mind the upkeep, the steam room is the one that gives you that, and nothing else will.
A common mistake is pricing only the generator or heater. For a steam room the walls, ceiling, drains and labor outweigh the equipment in the ranges above.
Frequently asked questions
What is the difference between a sauna and a steam room?
A sauna uses dry heat at roughly 150–200°F and low humidity, while a steam room runs around 110–120°F at or near 100% humidity. The build differs too: wood and a heater against a sealed, waterproof enclosure with a generator.
Which is cheaper to install at home?
On most of the sources I read, a sauna, especially a kit, costs less; Haven of Heat puts a steam room at $10,000–25,000+ in total against $2,000–15,000 for a sauna. Fixr shows them within $400 of each other for a tiny room, so get local quotes.
Do I need special wiring for a steam room?
Generators are 240V devices. The Mr. Steam 6 kW listing calls for a 30 A breaker and 8 AWG wire. Have an electrician check your panel against the exact model.
Can I convert my shower into a steam room?
Possibly. The contractor article describes steam showers built with vapor-controlled walls and ceiling, a generator in a mechanical room or soffit, and a steam head placed away from seating. Glass doors are a known weak point, so check the maker's instructions.
Is a steam room or a sauna safer for someone with a heart condition?
I can't answer that medically. The American Lung Association says people with high blood pressure or heart conditions, and pregnant people, should talk to a healthcare provider about precautions. Do that before using either.
What I would do
If I had a free corner, a modest budget and no tile project coming, I'd buy a sauna kit, get an electrician's quote for the 240V line, and skip the steam room entirely. The sauna vs steam room choice flips only if a bathroom remodel is already on the calendar, because then the waterproofing is partly paid for. In that case I'd ask the generator maker for its sizing sheet, confirm the slope and ventilation rules in the manual, and budget more for the enclosure than for the machine. In both cases I'd see my doctor first.