Saunas are good for your body, but they might be even better for your soul. That’s the guiding philosophy of three friends who are on a mission to spread the word about the traditional Finnish sauna experience.

Kim Johnson is a documentary filmmaker and Minnesota native of Norwegian and Finnish descent who has lived in Boulder for more than 20 years. When she recently decided to add a sauna outside her Colorado home, she turned to a couple of sauna-building friends for help: Jeff Cole, a meteorologist and Boulder native with Norwegian ancestry, and Todd Halunen, a Minnesota-born landscape designer with Finnish roots. Both men are enthusiastic home-sauna builders, and Halunen is in the process of launching a sauna-building business called Sielu Sauna. All three are obsessed with saunas, and they think you should be, too.

The trio of sauna pals, cooling off after enjoying a sauna together on a snowy weekend in Boulder. Photo by Benton Inscoe

If your only experience with a sauna has been in a health club or a hotel, it might well have left you cold. But a traditional home sauna is entirely different: quirky, personal, and imbued with ritual. “I grew up in northern Minnesota, which is the sauna capital of America,” Johnson explains. “It was part of the cabin lifestyle—to swim and fish and be very active outside, to take a sauna every night, and then jump in the lake and cool off and do it again.”

“Löyly” is a powerful word in the Finnish language. It describes the rising steam that comes from pouring water on the hot sauna rocks, and it can also be translated as “spirit of life.” For Finns, the sauna is an ancient sanctuary of peace and well-being, where you can escape your cares among a small gathering of friends and family.

Johnson’s Boulder sauna, handcrafted in white cedar by Cole and Halunen, with help from Johnson. Photo by Benton Inscoe

The physical impact of the sauna experience is intense. According to the Harvard Medical School, “The average person will pour out a pint of sweat during a short stint in a sauna.” The experts also warn that people with heart disease or uncontrolled high blood pressure should consult a doctor before trying a sauna. But, for those who practice regular sauna use, the benefits of increased circulation and increased heart rate can include pain relief, stress reduction, improved cardiovascular health, and potential relief from asthma and psoriasis.

The sauna’s spiritual and emotional benefits are equally profound. “You come out of there so different than when you entered—all this stuff just leaves your body; you don’t even remember what you were worried about when you walked in,” Johnson says. “The sound of the water on the rocks, the heat that emanates in the room, and the smell of the cedar—it’s so relaxing that I just sleep like a baby.”

So, what does a beginner need to know before building a home sauna? Johnson, Cole, and Halunen acquaint us with the basics:

Location: The beauty of a home-built sauna is that it’s infinitely customizable. “You can create a space out of anything,” Cole says. “If you want it outside, you could build it outside; if you want it inside, in an old closet or a bathroom, that’s great.” Johnson adds, “You just make it where it fits.”

Size: Consider how many people will be using the sauna. Just one person? The whole family? Cole suggests a five foot by seven foot-space as a standard size. “You can probably get five people in that space comfortably,” he says.

Prefabricated or custom-made: Do-it-yourself sauna kits—complete with wall and ceiling panels, benches, a door, a heater with rocks, light, and thermometer—are available in various sizes and shapes, and they can be customized to your liking. Amerec’s panel-built sauna kits range in size from 4-by-4 feet to 8-by-12 feet. Almost Heaven Saunas offers prefabricated barrel saunas and cabin saunas for two to eight people, in electric or wood-burning models, plus a range of indoor saunas for one or more people. Finnleo sells a variety of traditional saunas, from clever under-the-stair models to spacious spa retreats.

Materials: Traditionally, saunas are crafted from softwoods such as white or red cedar, fir, or hemlock. “The glorious, pungent smell of fresh white cedar—there’s just nothing greater than that smell in my mind,” Halunen says. “I also see people using aspen because that’s a really light wood, with very few knots,” he adds. Rocks should be chosen with care: “There are only certain rocks that you want to make sure are in there, and they tend to be glaciated granites, [which] are very dense and typically do not hold water,” Halunen says. “Because there is the danger of [rocks], you know, sort of exploding.”

Heating system: Specialized electric or wood-burning sauna heaters are available individually or as part of a kit assembly.

Cost: The cost of building a home sauna varies widely, depending on size and materials, but a basic sauna set-up starts at about $5,000.

Johnson’s sauna features a rustic door handle made from a piece of found wood. Photo by Benton Inscoe

Details: Get creative and make the sauna your own. Bench, window, and door design; lighting; water buckets; ladles; magazine racks; and more décor are all up to you. When Halunen builds a sauna, he pays special attention to the door handle, often scavenging pieces of wood from live trees in northern Minnesota. “There’s still lichen and moss on them,” he says, “and I don’t sand them down; I let people do that over time when they grab it with their hand, and it creates this beautiful, natural patina.” The stove Johnson bought for her sauna came equipped with rocks, but she preferred to choose her own, so she went into the mountains and gathered some from the Fraser River. “I just love that every little touch in there, I know where it came from, and each thing has a story,” she says. “That’s what’s really comforting.”