The Business of Aufguss

Aufguss is arriving in the US on a business case, not a cultural argument. Bathhouse is pacing toward a $120 million run rate in New York. Othership raised $11.3 million to bring its performance-sauna model to the Upper East Side. Paris's new Sant Roch cleared 85% occupancy in its opening month on a disciplined version of the same formula. The ritual that began in German-speaking Central Europe has become a commercial asset class, and US resorts and hospitality groups are starting to ask the right question: does it actually pencil?

The cleanest public number in the category comes from Galgorm Resort in Northern Ireland, which hosts the 2026 UK Aufguss Championships this week and has run a Celtic Sauna Infusion program for nine years. The resort reports roughly £10,000 (about $12,700) a month in ritual revenue from a single 30-seat sauna, priced as a £20 add-on to existing spa packages. That is the headline. It is also the one-line version of a P&L that has four other lines US operators need to model honestly before they commit.

The Revenue Line Is Thinner Than It Looks

Galgorm runs three guided 15-minute sessions a day in a 30-seat room. That is 2,700 seat-slots a month. At £20 a seat, a theoretical sell-out month would clear £54,000. Galgorm is clearing £10,000. The implied utilization is about 18.5% of maximum seat-hours.

That number is not a failure. It is what a resort spa looks like when ritual demand concentrates on weekend and overnight guests and thins out on a Tuesday afternoon. Urban bathhouses invert the shape. Sant Roch deliberately caps bookings at roughly half of its sauna's physical capacity and then runs that bookable inventory at 85% occupancy. Bathhouse is on a membership-plus-drop-in model that drives repeat visits through the week. Both are built for different demand curves than a resort that sells a spa day to its Saturday couples and a quieter ritual to its weekday conference bookings.

The operational point: a US operator pro-forma'ing an Aufguss room to a £54,000 number will be wrong. Building it to a £10,000 number, with upside to £15,000–£25,000 depending on mix, is the honest exercise.

The Galgorm math: 30 seats × 3 daily sessions × 30 days = 2,700 potential seat-slots. £10,000 monthly revenue ÷ £20 per seat = 500 seats sold, or about 18.5% of theoretical capacity. Resort demand is weekend-weighted; assume that pattern.

The Labor Line Is Where the Model Wins

The structural reason Aufguss works as a product is the labor ratio, and it is worth being specific about it. A standard hotel massage room is one-to-one: one licensed therapist, one guest, one hour, a 50% therapist commission on the revenue. A 30-seat Aufguss room run by a single Sauna Master is one-to-thirty on the same 60-to-75-minute footprint. The venue that hosted the 2025 UK Championships at ARC in London's Canary Wharf seats 65. Some European performance saunas seat 90.

That ratio is the entire investment thesis. Othership's reported $140,000 revenue per employee across 152 staff exists because 50-to-90-seat performance saunas replace treatment rooms entirely. The same lever is what makes Galgorm's £10,000 work at 18.5% utilization: a single Sauna Master's shift can carry hundreds of guests a week.

But the lever has a real cost. A certified Aufgussmeister is not a spa attendant. The training investment is serious (European academies like Aufguss Roots, Flow Aufguss, and Loylymasters run multi-week certification programs covering thermodynamics, essential oil chemistry, cardiovascular response in extreme heat, and the choreography itself), and the talent pool is thin outside Central Europe. US operators should expect to pay at a premium to a standard spa attendant hourly rate, and they should expect to spend on bringing in European trainers before a domestic program is credible. Bathhouse, Othership, and a handful of US resort programs are already competing for the same small cohort of certified practitioners. That supply-side pressure is the real constraint on how fast the category scales.

The Energy and Liability Lines Are the US Gotchas

Commercial performance saunas draw meaningfully more power than a residential room. A 30-seat space typically runs a 20-to-30-kilowatt heater versus roughly 9 kilowatts for a backyard unit. Three peak sessions a day plus ramp-up and standby add real kilowatt-hours to the P&L, and the room itself has to be built to a commercial ventilation spec to handle the humidity swing when water and ice hit 392°F stones. None of this is prohibitive, but it is a meaningfully different capital build than a relaxation sauna.

The larger unknown for US operators is liability. A standard hotel spa waiver does not contemplate 30 adults in a 176°F room while a staff member throws essential-oil-and-ice balls onto 392°F stones and swings a towel at 194°F ceiling air. Undiluted essential oils are flammable; respiratory events from over-dosed menthol or eucalyptus are a documented risk; heat exhaustion at 15-minute exposure to peak ceiling temperatures is real. Every European certification program teaches oil dilution at 3 to 10 drops per liter of water or crushed ice, plus medical-response protocols for guests who bail out early.

Bathhouse and Othership have not publicly shared their US insurance framework, but both run dedicated staff training, explicit informed-consent processes, and medical response protocols that go beyond a standard spa release. US operators installing their first Aufguss room should budget legal and underwriting work as a line item, not an afterthought. It is the piece European reference cases cannot fully answer.

The Revenue Per Square Foot Comparison Is Not As Clean As It Looks

If a spa director is reading this on an A/B basis against a traditional treatment room, the math cuts both ways.

A 30-seat Aufguss room with its cool-down area and queue is roughly 500 to 700 square feet. Galgorm's £10,000 on that footprint is about £15 to £20 per square foot per month of gross revenue, or roughly $19 to $25. A 100-to-120-square-foot massage room, booking at $130 a session with six daily bookings at 70% utilization, clears about $16,000 a month on a tenth of the footprint: around $130 to $160 per square foot per month gross. On pure revenue per square foot, the massage room wins.

But massage pays roughly half the revenue back out as therapist commission. Aufguss pays one Sauna Master a shift to cover every seat in the room. Net of variable labor, the comparison looks very different, and the real question is which constraint an operator is trying to relax. If the bottleneck is licensed therapist hours (which US spas universally say it is), Aufguss buys capacity you cannot otherwise hire. If the bottleneck is floor plan, a performance sauna is a harder call.

The Craft Is Professional Now. That Matters.

Zak Moore, Galgorm's 20-year-old reigning UK Aufguss Champion, did not come up as a performer. He started as a spa attendant at Galgorm, was sent to Farris Bad in Norway to apprentice under Lasse Eriksen (vice president of the Aufguss World Masters), and came back to win the 2025 UK finals in front of an international jury at ARC in Canary Wharf with a routine built around a Dublin pub owner, a leprechaun, and Irish music the room sang along to through peak heat around 176°F.

The point is not the leprechaun. The point is that a career path for commercial Sauna Masters exists now, and the 2026 Aufguss World Masters calendar is the supply-side proof.

The circuit has also split. "Show Aufguss" keeps the costumes, lighting, narratives, and music. "Modern Classic" strips those out and judges strictly on towel technique, heat distribution, and essential oil pacing. That bifurcation is not just an in-industry debate (Harvia sponsored the 2025 Verona Worlds using an EOS heater, a deliberate positioning play for the German premium commercial market). It is a product decision for any operator installing a program. A resort selling theatrical recovery experiences should run Show. A program pitched to returning members on a nervous-system-regulation story should probably run Classic. Most US operators will end up running both, on different nights.

What Operators Should Actually Watch

The Aufguss USA Nationals at Bathhouse in May will be the first clean test of US practitioner depth. If the field is strong, the supply-side constraint is loosening faster than the skeptics expected. If it is thin, that confirms the training pipeline is still the bottleneck.

On the operator side, the signals worth tracking through the back half of 2026 are which US resort groups announce in-house Aufguss programs; which heater distributors (Finnleo, Amerec, Almost Heaven, SaunaLife) start marketing performance-sauna configurations with tiered seating and commercial ventilation rather than residential builds; and whether a US underwriter publishes commercial insurance guidance tailored to communal performance rituals. The first insurance carrier that does will probably write a large share of the market.

Aufguss is not a trend. It is a second product line for thermal wellness, with a different labor curve, a different demand curve, and a different liability profile than anything on a standard US spa menu. The operators who model it honestly (18% utilization on a resort, 85% on an urban club, Sauna Master pay above a standard attendant, a real commercial insurance build) will capture the margin. The ones who pro-forma a sellout and underwrite like it is a relaxation room will build the room and then quietly shut the program down.

Three dates to watch: Aufguss USA Nationals at Bathhouse in May, the first US resort groups to announce in-house programs in the second half of 2026, and the first US commercial insurer to publish dedicated performance-sauna guidance. Separately, watch Zak Moore defend his UK title at Galgorm this week and qualify for the World Masters playoffs in the Netherlands in August.

The business of Aufguss is a labor-ratio trade, not a revenue-per-square-foot trade. US operators who understand that distinction will build the right rooms, staff them correctly, and make the model work. The rest will install a heater, hire a performer, and be surprised when the P&L looks like a resort spa instead of an Othership.