RSHP designs a Vierendeel townscape building for Mandarin Oriental Mayfair

A Clivedale development, Mandarin Oriental Mayfair is the first new-built luxury hotel in Mayfair for over a decade, offering 50 guest rooms and suites and 77 private residences, award-winning chef Akira Back’s first London restaurants, two bars, and a spa with a 25-metre pool. The building embraces the significant increase in footfall due to the new Bond Street Elizabeth line station and the renewal of Hanover Square and its public realm, part of Westminster’s wider strategy to enhance the vitality in this part of London.

RSHP’s new scheme provides a contemporary townscape response to the unique scale and historic urban grain of Hanover Square. The use of deep white reveals to window openings and Juliette balconies, formed by an innovative expressed structure, creates a subtle complexity to the façade to mirror the existing traditional white stucco that dominates Mayfair. Handmade elongated bricks, held in framed panels, provide a contemporary interpretation of the colour and proportion of Hanover Square’s red-brick Georgian buildings.

Graham Stirk, Senior Design Director, RSHP, said: “Inspired by the grand Georgian terraces of historic Mayfair, our design creates a unique structural system that responds to the vertical scale of the neighbouring façades. Bracing large flexible floor plates, the structure responds to the client’s brief, without the use of a central core. This creates a richness that complements the historic setting of Hanover Square, whilst giving subtle cues to the building’s fabrication and structural integrity.”

Uniquely, the façade is composed of a visible Vierendeel structural frame, expressing primary column and beam elements infilled with brick panels and glazed window openings.  Whilst Vierendeel structures are traditionally horizontal and used in bridges or long-span trusses, RSHP and Ramboll Structural Engineers have designed a vertically-oriented structure to support a contemporary architectural expression of wide internal spans, offering the client highly flexible floorplates and the opportunity for a grand ‘townscape façade’.

The building’s section resolves a complex spatial puzzle with the bulk of the building located within the centre of the city block, with a smaller percentage articulated towards Hanover Square and Brook Street. RSHP’s new building is formed of two ‘pavilion’ towers, connected by a glazed stair and lift core that links all levels, whilst permitting natural light to flood deep into the plan and lower-ground floors. 

Behind a structural colonnade, the hotel and residential entrances take the form of a covered public entryway which provides access to a glazed double-height lower-level covered courtyard restaurant. A rooftop bar and terraces provide generous views over Hanover Square and wider Westminster.

The steel and concrete exoskeleton structure is highly crafted and scaled to ensure legibility. On closer inspection, the detail and materiality of the constituent elements are revealed. The steel cruciform-shaped Vierendeel structure, finished white, contains a hand-finished composite structural concrete infill, with a polished outer layer of ash/concrete mix that provides a basalt-like finish, echoing some of Hanover Square’s sand-lime brick façades.

Maurice Brennan, Associate Partner, RSHP, said: “The building’s primary expression is a visible Vierendeel exoskeleton structural frame entirely fabricated off-site. The external composite frame wraps around the site with only minimal internal structure. We wanted to give Clivedale maximum flexibility in occupying the floors and the ability to respond to future changes in the residential market whilst meeting the complex needs of the Mandarin Oriental Hotel Group. 

The perimeter steel Vierendeel columns are only the size of an A4 sheet of paper. Internally, there are only four structural columns in each of the two primary building volumes.”

All primary structural elements were fabricated off-site, including the 684 beams and concrete internal columns. This enabled the efficient construction of a unique Vierendeel-structure building of considerable scale on a restricted site closely bounded by neighbouring buildings on three sides. The façade design can be dismounted and easily reused or recycled at the end of life. 

Ed Blake, Director, Clivedale, said: “It has been a really rewarding experience working with RSHP on this project as challenges became opportunities to think differently, and we are delighted to deliver something really exceptional. The showpiece of the architecture is the white external Vierendeel frame structure that gives huge flexibility on how we were able to organise apartments and the Mandarin Oriental Mayfair, London hotel internally. I also personally love the way the glazed core between the two main pavilion buildings is activated at night by the lights on the underneath of the lifts rising and falling against the night sky.”

Susanne Hatje, General Manager, Mandarin Oriental Mayfair, London, said: “To open a hotel and residences on Hanover Square, Mayfair's oldest square, is such a privilege and we wanted to ensure the design of the building paid respect to its surroundings. We are delighted with the result which responds to the vertical scale of neighbouring facades and complements the historic setting of the square, this in turn inspired the interior design of the property's public spaces, created by Tokyo based studio, Curiosity, who have based their concept on 'a hub of nature and art'.

Client: Clivedale / Mandarin Oriental Hotel Group
Architect: RSHP
Structural Engineer: Ramboll UK
Services Engineer: Hoare Lea
Access Consultant: Reef Associates
Delivery Architect: AFK
Landscape Architect: Spacehub
Townscape Consultant: Richard Coleman Citydesigner
Contractor: ISG
Quantity Surveyor: Gardiner & Theobald
Interior Designer: Studio Indigo, Curiosity