Recently, a friend asked me which electrically heated sauna kit I would recommend. As part of the process of looking at several options on the market, I developed these seven helpful criteria. My apologies if you can’t find one that meets all of these; hopefully the market continues to improve. Keep in mind that you can make custom adjustments to most kits after purchasing them to improve their function. And lastly, many of these criteria also apply to wood-burning kits.
#1. Robust heater
Sauna is primarily known for being a hot space, so a good heater is the first criterion to consider.
- Proper sizing (usually in kilowatts): If it’s your goal to drive 80 mph on the highway, you don’t want a car whose max speed is 90 mph—you will constantly be pushing your engine to its limits. Also keep in mind that you might need to up-size your heater a bit if your kit has large windows (I generally don’t recommend this), thick walls, lots of rocks, or you live in a cold climate.
- Lots of rocks: I recommend 100-200 lbs. (45-90 kg.) for small saunas and 200-400 lbs. (90-181 kg.) for medium saunas. The more rocks you have, the more heat you can capture and use to create steam for your sauna session.
- Safety certification: Most electric heaters in the U.S. market are UL 875 certified. While it is nice to have this certification for safety, insurance, and passing inspection, it is not without some downsides. UL 875 limits the temperature to 194°F (90°C), the heating time to 1 hour (so you constantly need to babysit the timer for longer sessions), and requires a high limit sensor in the stove (which can cause constant nuisance trips). Meanwhile, in Europe, heaters without these restrictions have been safely used for decades. Their limits are: 230°F (110°C), 3+ hours heating time, and no high limit sensor that constantly needs reset. But recently, UL has developed a second option (#60335-2-53) for the U.S. market that harmonizes with the European norms. Unfortunately, as of 2026, there aren’t many products on the market that meet this standard. A few options that you might consider are ILO brand and various models from Finland and Estonia, but make sure to check with your local building inspector before going with a non-UL heater.
#2. Bench location and depth
Bench location: Once you have the ability to create intense heat and steam, it is important to be able to take advantage of them. This is why the upper bench should be near the ceiling—somewhere in the range of 40-48 inches below the ceiling (you measure down from the top of the hot room, not up from the floor). If you plan on using birch or oak vihta/venik, you might need a little extra space to swing the branches.
Sauna height: A taller sauna has less temperature stratification, but I wouldn’t stress about that too much. If your feet are a bit cool, pull them up to the top bench. If you can get one that is 7.5-9 feet tall, you should be good.
Bench depth: It’s very nice to be able to lie down on the upper bench without feeling like you are going to roll off. It’s also good to have the ability to sit cross-legged. I recommend a depth of 28 inches or greater.
#3. Ample Ventilation
Most saunas need more ventilation. A Finn once told me, “I like a drafty sauna.” This is the trickiest of all the criteria because ventilation is invisible and the effects are subtle; most people don’t know what to look for. Usually the main effect of not having sufficient ventilation is an inability to handle the heat for very long.
There are lots of conflicting recommendations online and very little good education about this topic, but most of the time the answer is that you need more ventilation than you think. Some heaters require a vent near the base of the heater (UL 875 and wood-burners). I generally recommend two to three sizable vents below the upper bench that are adjustable. Things like open flooring, very cold exterior temps, and prevailing winds can complicate the situation.
#4. Drainage
From ancient times, sauna was a way to bathe, and in many Finnish communities it still is. This is one of the reasons why every sauna benefits from having a drain—and not just a tiny drain near the stove for stray splashes; it should be able to handle lots of water from any place in the hot room. A drain makes cleaning easier, makes washing/bathing possible, and allows sauna-goers to rinse off sweat and cool down during the sauna round. If you’ve never tried that last one, you should!
#5. Walls and wood
Simple construction is often the best. Some sauna kits have panel walls that are a sandwich of wood paneling, insulation and maybe a vapor barrier, but I prefer solid wood walls. This gives the sauna more thermal mass and less chance of insect, rodent, or moisture infiltration into the wall cavities. Solid wood walls sometimes take longer to heat, but once heated, they provide a more even and longer sauna session.
Cedar is often seen as the default for saunas, but that is a relatively new development. Redwood and pine used to be the more common choice on the market. I often recommend non-cedar woods because they are usually less expensive and are less likely to cause or exacerbate allergic reactions (which sometimes happens with cedar).
I am not a fan of large windows in saunas. They don’t have much thermal mass and sometimes it’s nice to have a darker, more subdued environment in a space that is exposing you to sensory stressors (heat and steam).
#6. Robust, reliable roof
I recommend a sloped roof over a flat roof (it doesn’t have to be super steep) because there is less chance of leakage. Its covering should also be made of a durable material that won’t deteriorate. I prefer metal roofs.
#7. Affordable
I don’t view sauna primarily as a luxury spa for the wealthy (though it can be that too). Historically, it was a log cabin for village bathing and other tasks. It was humble and practical. That said, I also understand that the people making sauna kits need to make a living and have a sustainable business. The cost range (North America - 2026) for an approximately 6′ × 6′ sauna that meets the aforementioned criteria and comes with an electric heater and controller should be in the $11,000-17,000 range (I wish it was less); this includes shipping, taxes, and all fees. Keep an eye out because sauna companies often run sales that offer sizable discounts.
*Addenda: Barrel and cube saunas are very popular but they don’t hold up super well. Most sauna kits don’t come with a changing room, but for many Finns having one is a must. Large hot rooms tend to have better heat and give you more room for hosting.