How Luxury Hotel Brands Are Betting Big on Thermal Bathing Suites

Over the past two years, nearly every major luxury hotel group has announced significant new investment in thermal bathing facilities. What was once a supplementary spa amenity is becoming a centerpiece of the guest experience and, increasingly, a primary reason people book.

Who's Building What

Aman, which has long integrated bathing rituals into its properties, is expanding its thermal wellness programming across its pipeline of new openings planned for 2026 and 2027 in locations including Japan, New Zealand, and Vienna. KLAFS, the German sauna manufacturer now owned by Kohler, has become one of the go-to partners for ultra-luxury hotel sauna installations.

Four Seasons has engaged Finnish design consultants for thermal bathing concepts at multiple upcoming properties. Mandarin Oriental's newest Asian properties feature multi-room thermal circuits inspired by both Nordic and Japanese bathing traditions.

Thermal bathing isn't an amenity anymore. It's the experience. Guests are traveling specifically for this.

The Business Case

The investment makes financial sense. Industry consultants report that hotels with dedicated thermal bathing facilities see meaningfully higher spa revenue per guest compared to properties with conventional spa offerings. The trend is particularly pronounced in Nordic, Alpine, and Japanese-inspired hospitality concepts, where the bathing experience is woven into the architecture itself.

Key Trends: Multi-room thermal circuits (sauna, steam, cold plunge) replacing single-room spas. Geothermal and sustainable heating as selling points. Finnish and Japanese design influences blending in new builds. Equipment partnerships with KLAFS, Harvia, and custom fabricators.

The shift is also changing how these projects get designed. Rather than bolting a sauna room onto a basement spa, architects are now integrating thermal suites into the primary guest experience, with natural light, outdoor access, and views treated as essential features.

Equipment and Partners

KLAFS, which Kohler acquired in 2023, has emerged as the dominant supplier for ultra-luxury hotel sauna installations globally. Harvia's commercial division is growing rapidly in this segment as well. Custom stone, glass, and wood fabrication is becoming standard in the high end, pushing projects well beyond what off-the-shelf manufacturers offer.

For the sauna industry, luxury hospitality represents both a revenue opportunity and a brand-building platform. A KLAFS installation in an Aman property does more for the brand than any trade show booth.