Luxury health club operator Equinox has converted a historic bank building in London's Mayfair into a gym, spa and member’s lounge, with the opening scheduled for next month.

The ground floor, basement and mezzanine levels of 12 St James’s Street have been transformed by architects Woods Bagot and interior designer Joyce Wang to create “an intimate, science-fuelled environment that awes with beguiling spaces and exceptional details”.

External alterations to the building, renamed 'E St James’s', have been kept to a minimum, although new louvres have been added to the basement level façade. Internally, major structural modifications have been made to the mezzanine to accommodate the club’s cardio zone and treadmills.

Speaking about her design approach, Wang told CLADglobal: “The interiors are clad with beautiful and rare marble, which we have retained.

“We inherited this amazing architecture, but at the same time we wanted to create an interior design that is characterised by bold modern forms and materials to give the space a new life.”

Facilities in the club include strength and cardio training zones, a private Pilates studio, a regeneration room, a cafe and lounge and a steam room and spa.

The latter is focused on regeneration and will offer treatments including targeted cryo-therapy, cryo-facials and cryo-peels, bema vascular therapy, compression therapy, oxygen facials and performance massages.

A £350-per-month membership package comes with an Equinox ‘wellbeing passport’ that grants access to all of the operator’s clubs across the US and Canada.

Members can undertake a hyper-personalised training programme with Equinox’s most elite personal trainers, which includes an assessment involving a 3D body scan, active and resting metabolic rate tests, blood pressure, functional movement screening and an in-body composition analysis.

Equinox has also appointed its first experience director to take on the role of concierge, while a complimentary gym laundry valet service means gym-users can collect their washed, ironed and prepared kits when they check in.

E at St James’s is the second Equinox property to open in London, following the arrival in 2012 of Equinox Kensington. A third health club is scheduled to launch in Shoreditch in 2019.