Cottonmill, a new private members' spa, is set to open at Sopwell House in St Albans, Hertfordshire, this summer, following a £14m investment.

Nicknamed 'The Garden Spa' while in development, Cottonmill has been designed as a luxurious destination spa that boasts a strong connection to nature. It's ethos is one of community and choice.

It was designed by consultancy firm Sparcstudio and combines the serene environment of a spa with the exclusivity of a private members club.

Designed to create a seamless spa journey and celebrate its natural surroundings, the spa features a neutral palette and and natural materials, such as Onice Smeraldo marble, terracotta and fluted timber paneling. It will play host to three floors housing 18 individually-designed suites. The central spa and treatment suites will surround a private courtyard spa garden, designed by landscape artist Ann Marie Powell.

Beverly Bayes, director at Sparcstudio, said: "We worked closely with garden designer Ann Marie Powell to create a seamless transition between the inside and outside spaces. The interiors aesthetic that we have developed could be described as 'Refined Nature' with a materials palette formed from cool neutrals, warm terracottas, dark green slate, lime washed oak veneers, concrete, and fluted timber paneling."

"Great attention was applied throughout the project to the detailing of all the bespoke elements to achieve a unique and totally luxurious experience but with an informal 'barefoot' feel.

"Special attention has been paid to ensure a smooth flow and exciting journey for different spa users," she added.

Facilities will include a thermal suite, offering four sauna and steamroom experiences, including an organic sauna, panoramic sauna, salt steam room and botanical steam room. A Deep Relaxation Room, outfitted with Four Senses loungers, provides a cocoon-like environment designed to help guests reach a meditative state.

The Whisper Room provides a quiet relaxation space, while the Garden Room does the same while offering views across the spa garden. The Rose Relaxation Room is a post-treatment space, with individual zones separated by rose-tinted glass screens and sheer cotton to provide privacy. Its walls are lined with acoustic 'petals' to minimise noise.

The Sitting Room serves as a social hub, where guests can get snacks or drink, and the Pantry, the spa restaurant, allows guests to dine in their robes and boasts a menu of daily Chef's specials, seasonal dishes and desserts.

A gym kitted out with Technogym Artis equipment and a studio hosting pilates, yoga and HIIT classes complete the spa's offering.

In addition, the spa will feature a number of experience showers, such as Sensory Sky and Aqua Moon, supplied by Dornbracht, and will offer an extensive treatment menu, offering rituals – based on the healing powers of sand and water – from Elemis, ESPA and Aromatherapy Associates

It will also be one of the first spas in the UK to offer treatments on an Amber & Quartz Crystal Bed, which delivers a form of thermal therapy by immersing the body in hot sand. Treatments will include the Cottonmill Sound & Sand, which will combine gentle vibrations and singing bowls, and the Elemis Quartz Poultice Massage, which uses warm quartz poultices to ease muscle tension and increase circulation.

Richard Macklin, spa director at Cottonmill, said: "The team and I are hugely looking forward to sharing our new spa concept with guests this summer."

"As a private members' spa Cottonmill is the first of its kind offering a community setting, innovative new treatments and experiences from across the globe, contemporary design, modern dining and a new spa garden - all in one place in the heart of Hertfordshire. We can't wait to welcome guests and mark the beginning of this new and exciting chapter for Sopwell House."

Rafael Bejerano, owner of Sopwell House, said: "We are tremendously excited about unveiling Cottonmill at Sopwell House; a new destination spa in the heart of Hertfordshire countryside. We want our guests to have an enhanced spa experience, unlike any other in the area. The team and I are immensely proud to have achieved such a project, providing a number of jobs for the local area, which is testament to the rising importance of domestic tourism in the UK, and a unique new luxury spa experience."

The spa will offer two membership tiers and will put guests completely in control of their spa experience.