How Eric Parry Architects built a spa on the roof of London’s Four Seasons Hotel. By Felix Mara. Photography by Edmund Sumner
Eric Parry Architects’ spa for London’s Mandarin Oriental Hotel was so warmly received when it opened in 2000, that it might well have been tempting to roll out an identical design for a similar commission at the Park Lane Four Seasons Hotel. But this spa, which opened in March, is constructed on the roof of a 1970 luxury hotel. Part of a general overhaul by ReardonSmith Architects and interior designer Pierre-Yves Rochon, it presented an opportunity to take a new approach and posed a different set of technical problems.
‘That was a cave,’ says Parry, referring to the basement spa at the Mandarin Oriental. Nevertheless, just as the design of the Mandarin spa was informed by Parry’s 1998 student residences at Foundress Court for Pembroke College Cambridge, which explored themes of privacy and communal space, the Four Seasons spa builds on his work at the Mandarin.
As luxury hotel facilities, both are distinct from the many other types of spa, and their purpose is to promote mental and physical well-being through a series of treatments and activities. Like the Mandarin spa, the facility at the Four Seasons comprises a linear sequence of spaces, from the reception to various types of treatment rooms to relaxation areas. This involves the central process of retreating from the outside world and what Parry calls ‘an intense interiority’.
Whereas the setting for the Mandarin spa (which has no daylight) was ideally suited to this process of withdrawal, at the Four Seasons Parry had to devise ways of concealing distracting views from the tenth-floor facility. But he also took the opportunity to establish a dialogue with the outside world, with a graded sequence of increasingly cocooned spaces and a return sequence with a progressively transparent external envelope and panoramic views across Hyde Park, Green Park, Knightsbridge, Mayfair and Buckingham Palace.
In order to create what he calls a ‘celestial world’ and regulate light and views, Parry has applied a graded ceramic frit to the low-iron external glazing. Behind this he has draped bespoke semi-transparent curtains, designed by Eric Parry Architects associate Merit Claussen, who is a textile designer as well as an architect.
These were created to be diaphanous, crinkly, pleasant to handle, lightweight, colour-fast, non-combustible, flame-retardent and to retain their shape and colour after regular washing. Manufactured in Switzerland, they are double-woven, with a nylon warp and a dyed enamelled copper weft. Along with the spa’s horsehair wall panels, they also provide acoustic softening to counteract sound-reflective finishes such as granite flooring and wall surfaces with over 20 coats of lacquer. The spa’s rich materials are variously chosen to regulate moods and light levels, deal with wet and humid conditions, and resist wear and tear during its 18-hour shifts.
With high-density cladding materials, vitality pools, underfloor heating and heavy services, mainly accommodated in a 1.1-metre deep plenum below the spa, its structural design was particularly challenging. Structural engineer Adams Kara Taylor has resourcefully worked within the constraints of the existing building, while remaining wholly sympathetic to Parry’s design intent.
Like many hotels, there is a significant transfer structure between the cellular bedroom floors at upper levels and the larger reception and function spaces on lower levels. Additional load had to be minimised so that the impact on the existing transfer structures was reduced.
Having investigated the existing building to establish where it had surplus capacity, we lessened additional loading by using lightweight materials where possible without compromising the quality of Parry’s design, and spread the new loads across points where the existing structure could bring them safely to the ground.
The new roof and floor are supported on a steel girder transfer grillage off the existing tenth floor. The new loads are sent directly down the concrete columns that were proven to have surplus capacity.
The new tenth floor was formed using lightweight composite flooring and composite beams in order to keep additional loads to a minimum. Many elements of the existing floor slabs had to be opened up to form new spaces. Carbon fibre reinforcement was used extensively to stiffen and strengthen new openings.
Stuart Sagar, associate, Adams Kara Taylor
Four Seasons Hotel, London, by Eric Parry Architects