The W group's Amsterdam hotel has been extended with the renovation of the historic Bank building, which houses a 300sq m (3,229sq ft) Away spa set in the former vault.

Originally designed by F.W.M. Poggenbeek in 1908, the building was one of the first concrete constructions in The Netherlands.

Spa consultant 4SeasonsSpa worked with designers Baranowitz + Kronenberg and consultants Raison d'Etre to create the spa, which is housed behind the original 4,000kg vault door and features a black and gold theme to represent the building’s former use.

An urban retreat built into two original vaults, the Away Spa includes seven treatment rooms, a sauna, steamroom, wet area with fire bath and plunge pool and a relaxation zone. The spa’s black walls and gold accents provide a backdrop for treatments, such as the Diamonds Don’t Lie Facial by Gemology, which uses diamond powder in its skincare.

“The Bank building is filled with clever and playful touches, including the Away Spa, which provides a W Spa experience like no other,” said Jenni Benzaquen, vice president of luxury brands, Europe, Africa and Middle East.

On the rooftop, 4SeasonsSpa has installed a Wet Deck, with a 25m outdoor whirlpool, and the consultancy also worked on the hotel’s Fit workout space.

The Bank Building also houses X Bank, a “creative incubator space that showcases the city’s leading talents in art, fashion and design,” as well as several restaurants, a bar and 66 bedrooms and suites.

Architect Wingender Hovenier (WiNHOV) has overseen the transformation of the space, working with Baranowitz + Kronenberg, and a diamond and gold theme can be seen throughout.

Black and gold bedspreads were created by Dutch textile designer Aleksandra Gaca, while the pillows, designed by Sabrina Bongiovanni, represent Amsterdam’s famous window sills. As a finishing touch, all mini-bars in the building are shaped in the form of a bank vault.

The W Amsterdam has 238 bedrooms in total, spread across two buildings, the bank and the Exchange, a former telephone exchange building.