New edition is completely updated, including an all-new look and layout, more in-depth detail on popular hydrothermal features, detailed design process guidance, as well as communal bathhouse design and operational advice

In celebration of 10 years of industry leadership, the Global Wellness Institute proudly unveils the fourth edition of the Guide to Hydrothermal Spa & Wellness Development Standards. This 230-page guide, developed in collaboration with the GWI Hydrothermal Initiative members, continues to set the industry standard for designing and constructing thermal experiences and wet areas in commercial and residential properties.

Originally published in 2014, the Guide to Hydrothermal Spa & Wellness Development Standards has proven invaluable for stakeholders, including owners, operators and consultants, to understand the complexity of these spaces. Regardless of the size and scope of a project, the manual guides readers through everything from project planning to building and construction considerations, including recommended standards and materials, while clearly defining the functions and benefits of common thermal bathing and wet area experiences and treatments, both communal and private.

“I’ve long been convinced that, when implemented correctly, hydrothermal experiences play a key role in wellness programming, offering proven wellness benefits that are difficult to achieve any other way,” said Susie Ellis, GWI’s CEO & co-founder. “GWI is proud to celebrate 10 years of providing the industry with this valuable resource. The fourth edition has been updated and expanded, and includes crucial information, which is available for free download, to help anyone embarking on this type of build, whether for a home, spa, bathhouse or fitness center.”

Download the latest Guide to Hydrothermal Spa & Wellness Development Standards.

To build these facilities correctly, precise technical knowledge is required: from material choice to complex drainage and electrical challenges. The required knowledge goes far beyond understanding what type of tiles can withstand high temperatures or which wood holds up best in a sauna. However, hydrothermal specialists are often consulted too late in the process, creating unnecessary costs and delays to correct issues that could have been mitigated much earlier in the build. The Guide to Hydrothermal Spa & Wellness Development Standards was developed to solve for this issue.

Key Considerations from the fourth Edition of the Guide to Hydrothermal Spa & Wellness Development Standards: 

  • Seek professional advice early: these are specialized areas and wet area specialists are required.
  • Be clear on budget: a wet area is not a place to cut corners; understanding this at the outset will minimize frustrations.
  • Know your audience: preferences around the world vary greatly so make sure hydrothermal features are targeted to your audience.
  • Balance is important: achieve the correct balance between water (pools) and thermal experiences (steam rooms, saunas, etc.).
  • Don’t underestimate space requirements: wet spa areas often require twice the space to accommodate behind-the-scenes equipment and maintenance.
  • Bathers and staff require different flows: understand who will be using and working in the various spaces and plan accordingly.
  • Don’t forget the plant room and equipment: the detailed plant and technical equipment requirements (plant rooms, etc.) are frequently undocumented in early planning stages; this omission often means going back to the drawing board partway through a build, resulting in time delays and extra costs.
  • Noise is the enemy: customer relaxation will be nonexistent and the ambience of the spa will be severely compromised if noise emissions aren’t kept to a minimum (for example, a relaxation space should not be adjacent to a vitality pool, which can be quite noisy and often generates conversation).
  • Water egress is also the enemy: a lack of detailed planning in the materials used, construction techniques and drainage can result in water leakage/damage throughout the facility, which can lead to health issues from mold and bacteria growth such as legionella. 

“Our main goal with this resource has been to provide information readers can’t find elsewhere.” said Don Genders, chair of the GWI Hydrothermal Initiative and CEO of Design for Leisure. “This book is the result of a unique collaboration between experts, written to enable readers to walk away with a clear understanding of how hydrothermal areas should be designed and constructed, while also providing historical references, wellness benefits, practical tips, and even common building mistakes—all in an effort to elevate industry standards and encourage builds that are both high quality and sustainable.”

In addition to the support from Hydrothermal Initiative members, sponsorship was provided by two flagship hospitality brands with a keen interest in hydrothermal areas: Accor and Hilton.

“Accor is a proud sponsor of the fourth edition of the Guide to Hydrothermal Spa & Wellness Development Standards, and I endorse it as an essential tool for anyone venturing into the creation of a hydrothermal zone,” said Emlyn Brown, global SVP of wellbeing at Accor. “Drawing from my extensive experience, I recognize the importance of getting the design and construction approach right. With the renewed interest in bathing, sauna experiences, and self-guided thermal journeys, this resource has never been more crucial.”

“Hydrothermal communal bathing has long been important to Hilton’s wellness offering and I know firsthand how challenging it can be to get these areas right. As a sponsor partner, we’re delighted to contribute to the GWI’s work to support excellence in design and function in this space,” said Amanda Al-Masri, vice president of wellness, Hilton.