Thirty years after it first opened, Center Parcs has unveiled its new Forest Spa concept at its 1,500sq m (16,146sq ft) Sherwood Forest location in England, showcasing 26 new spa experiences in a completely redesigned two-storey spa.

“This is not just a refurbishment, but an evolution of our brand,” said Sue Goddard, group leisure manager. “We don’t want to wait until our spa concept shows its age – we want to innovate, and we want to stay ahead of other spas.”

The £3m (US$3.9m, €3.5m) renovation took its inspiration from the resort’s surrounding forest, as well as from forests around the world, from Nordic landscapes to the high-altitude Chilean Arenal forest.

The forest spa concept is an extension of Center Parcs’ Aqua Sana brand, and will be used in the upcoming Longford Forest – the brand’s first location in Ireland – which is due to open in 2019. Elements from the concept will also be incorporated into the other four Center Parcs locations in the UK, which welcomed 350,000 people to its spas last year.

At the Sherwood Forest spa, six zones showcase an assortment of heating and cooling rooms, including a heated outdoor pool, foot spas, outdoor hot tubs, steam rooms, saunas, an ice cave and a selection of relaxation rooms, including one for forest meditation.

Decleor, Elemis and CND provide treatments in the spa’s 21 treatment rooms, and an anaerobic digestion plant near Sherwood Forest will provide almost all the heat and power needed for the spa, helping to reduce the spa’s carbon footprint.

The experiences are designed to transport guests to different forest regions; the Nordic Forest steam room features an alpine scent and swirls of pink and green lights designed to be reminiscent of the Northern Lights, a Scandinavian Snug offers a cosy relaxation space with fur accents within a wooden hut, and whistling winds can be heard in the ice cave.

“Wherever possible, we’ve opened up our spa to its natural surroundings, taking the experience outside and bringing that experience in,” said Goddard.

Inspiration was also taken from the Japanese trend of forest bathing, with outdoor areas and walkways designed to allow guests to reap the benefits of being among the trees.

But the pièce de résistance is the treetop sauna, built nearly 10m high, which offers views of the forest canopy and a stream below.

After guests identified the forest setting as something that sets Center Parcs apart from other resorts, Goddard, along with group spa manager Kay Pennington and the design team at Sparc Studio and architects Jackson Design Associates set about integrating that within the new spa concept.

“You don’t have to have a conversation about forests for very long before ‘treehouse’ comes into your head,” said Goddard. “And we thought: ‘Why can’t we build a sauna up in the trees?’”

The purpose-built treehouse is the first treetop sauna in the UK, if not the world, said Goddard, and Sparc Studio worked with Barr + Wray on the experience, “pushing the boundaries in terms of location and finish,” said Goddard. A cherry picker was brought in at the start to find out what the views looked like from the treetops, and where the best location would be.

“We’re lucky to have so much of this forest canvas around us to be able to open it up and use it,” said Goddard.