Castle Hotel & Spa is adding a $9M Thann Sanctuary Spa to the historic property.

TARRYTOWN, NY—Castle Hotel & Spa broke ground for the seven-month construction of the luxury $9 million Thann Sanctuary Spa, the first in the United States.

Thann Sanctuary Spas are known throughout Asia and offer a wide variety of spa treatments based on natural therapies.

According to Jiro Sato, president of Sankara Hospitality Group, which owns and manages the Castle Hill& Spa, "The development of the Thann Sanctuary Spa is the first part of a $10 million renovation project that includes 4,100 sq. ft. of meeting and banquet space, the 31 luxurious guestrooms and suites, public spaces and the award-winning Equus restaurant and kitchen."

The spa is slated to open in May.

The interior design by Gettys will incorporate warm tones and soothing light with furnishings procured from Thailand. 

The 7,800-sq.-ft. spa will feature separate locker facilities, hot pools, steam rooms for men and women, seven treatment rooms, a VIP treatment suite and an expansive relaxation lounge.

In terms architecture, Mike Flynn at Irvine, CA-based KTGY said the spa will be designed to be a simple, sophisticated building utilizing a low profile, stone walls and minimal exterior openings to blend with its setting overlooking the rustic landscape.

A curved stone wall will guide the guest through an opening in the wall into a sheltered interior courtyard. The spa walls flanking the courtyard will be transparent floor-to-ceiling glass creating a contrast with the solid stone wall exterior. 

Thann Sanctuary Spa  expects to be LEED (Leadership in Energy and Environmental Design) certified by the U.S. Green Building Council. Sustainable features of the spa will include a vegetated roof, high-efficiency heating and cooling systems and high-tech lighting controls.

Originally built in 1897 as a private residence, the Castle Hotel & Spa opened in 1997, 16 years after it was designated a historic landmark.