Playing with geometry

A new hotel in the south east Asian casino hotspot of Macau is a rare hospitality sector project for Zaha Hadid Architects, but a typically groundbreaking technical achievement for the practice. James Parker spoke to architect Viviana Muscettola about creating the world’s first free-form high-rise exoskeleton

Macau has positioned itself as Asia’s most popular entertainment destination, and with over 32 million tourists visiting in 2017, chiefly for the resort’s casinos, it has a strong case. Development has sprung up in the 21st century to service this large market as China’s prosperity has increased, with pastiches of Las Vegas hotels that are themselves pastiches of European architecture, including The Venetian and The Parisian. As a result, the arrival of a landmark new building creating its own futuristic statement, rather than harking back to the past, is a striking shift for the Cotai Strip, the hotel district of Macao built on reclaimed land. The region is now connected to Hong Kong across the Pearl River estuary via a 34 mile long bridge – the world’s longest sea crossing. The new hotel, called Morpheus, is the fifth in a group of high-rise hotels within the City of Dreams integrated hotel/casino complex, run by client Melco Crown Entertainment. However it stands out as an ambitious and unique design statement built to bring a wider range of holidaymakers to Macao. As the first hotel that Melco has operated as well as owned, CEO Lawrence Ho wanted a flagship building that “represented the company’s ambitions for the future,” project director at ZHA Viviana Muscettola tells ADF. Ho contacted Zaha Hadid herself in 2012 to see if she was interested in producing a concept. Muscettola says the practice made it clear at the first meeting that they weren’t interested in creating another Las Vegas-style hotel, and wanted instead to create a true ‘destination’: “We were completely aligned in the intention to create something which people would come to Macao specially to see.” Because of this, she says, “it had to reflect a new century design language.” The architects were given “quite a ‘brief’ brief,” essentially stating the minimum room requirements for what was a constrained site, and worked up a couple of concepts. The client opted to go for the more experimental option. Muscettola adds: “Ourselves and the client were a particularly good match, because Lawrence was as visionary as us in terms of wanting to design and build something for the future of Macao in general, for entertainment and hospitality.” Working initially from the London office, and then using its Hong Kong base and the skills of ZHA architect Bianca Cheung, Muscettola’s team arrived at a flamboyant and yet also efficient design solution.

Site & form

According to the project director, “from the beginning” (a favourite phrase of hers, illustrating the firm commitment to the design vision from client and architect), “one aspect we were sure about was that in contrast to the rest of City of Dreams, we wanted a continuous facade all the way to the ground.” Therefore rather than a traditional tower and podium, at ground level the building would give pedestrians a clear sense of the overall form, rather than have a visual disconnect between lower and upper stories. “This is something the office has been researching quite a bit in other projects, making the presence of the skyscraper recognisable if you are sitting under it.” Another more practical driver was that the designers were confronted with a requirement for 150,000 m2 gross floor area, within a footprint of 99 metres x 52 metres, and a height restriction of 160 metres with Macau airport being nearby. While the facade deliberately obscures the fact due to the web of aluminium-clad steel exoskeleton wrapping the entire exterior, there is in fact a podium within. This consists of four levels including the main lobby and gaming areas, which connect to other parts of the resort, retail and a spa (containing ‘real’ snow). Muscettola comments that the client had key requirements for this area: “It had to be porous while having enough footprint, giving enough visual connection between the different programmes.” The most arresting aspect of the overall form is the three massive voids carved from the centre of the block, turning the building into a hybrid of a solid volume and two towers connected by two organically-shaped bridges. While achieving the straightforward requirement of bringing light into a deep-planned building, this also creates a sculptural presence in the city inspired by the Chinese art of jade carving. There is something of the sense of a futuristic, avant-garde arch, but in fact the building has a genuinely unique aesthetic. The dynamically undulating glass facades also provide hotel and restaurant guests with exciting and unusual views of the building’s structure from within. This keeps them engaged with the building’s distinctive nature, and provides a new and unique visual backdrop for many rooms, ameliorating what are otherwise fairly mediocre external views. Muscettola says that for the client it was “important to make people want to explore the inside of the hotel they are in, rather than leaving to go somewhere else.” She says that the idea of “carving out” the core was present in the very first sketches, and are essential to how the hotel is a “a place of continual discovery” for visitors. This discovery starts at the 40 metre atrium, continuing to a pair of glass lifts which run up the sides of the voids, then to the two bridges at level 21 and level 30 which house restaurants, and finally the swimming pool in a sunken terrace on level 40. The diagrid-formed structural exoskeleton becomes free-form to clad the curving glass facades of the voids, but also has an architectural role on the flat sections of the building. It becomes increasingly less dense as the building ascends, for structural reasons, but this also means less restrictions to views for the upper floors of guest rooms, including luxurious two-storey ‘villas’ at the top level. These surround the swimming pool, giving it an intimate, courtyard feel and a human scale. The exoskeleton continues over the top of the building to also form the inner facade here.

Exoskeleton

The design intent behind creating an exoskeleton was essentially to further emphasise the dynamic form using the structure itself, and in this way Morpheus echoes other ZHA projects. “It came from the idea of reinforcing the free-form shape of the building and fusing it with its own structure,” says Muscettola. Buro Happold, who undertook the structural engineering in close collaboration with ZHA, were also instrumental in the decision to go for an exoskeleton, having done an early study to demonstrate it would be an efficient method on Morpheus. Muscettola: “Of course it’s more challenging from a construction point of view, but in terms of efficiency of the structure it’s the best solution for this kind of volume articulation.” The hotel also needed to be flexible to adapt to fast-changing guest expectations. Muscettola says that most of the hotels in Macau have a “very quick turnaround of internal programme”. As upgrades in technology occur and guests’ demands shift, hotel owners here tend to refit every four or five years. She explains that the use of the exoskeleton as a structural solution was as much of a result of the client’s ongoing requirements as aesthetic desires. “Having most of the structure outside of the building would free up space and give a lot of flexibility for future-proofing the building,” she says.

Engineering

Muscettola asserts that as a practice, ZHA “don’t do engineering,” but “want to work with the tectonics of a design and have them working as one element, one challenge.” There was undeniably a major engineering challenge in achieving the unprecedented feat of a tall building with a free-form supporting exoskeleton. The exoskeleton is partly responsible for lateral stability by being connected to floor beams using stubs within nodes in the diagrid – these being in turn connected back to concrete cores. As a result, there are very few internal columns. The exoskeleton is divided into three parts, firstly relatively standard flat wall sections, then curved sections at the corners, then finally the fully free-form sections following the organic shapes of the voids. In turn there are three types of glazing system – double-glazed unitised on the flat areas (“more than 60 per cent of the project is straightforward off-the-shelf floor to floor systems” says Muscettola), curved double-glazed at corners, and single-glazed in free-form areas. Here, to ensure structural integrity, the systems are formed as composites of triangular glazing panels – secondary steel ‘macroframes’ attached to the exoskeleton via stubs. Full aluminium sheet cladding was chosen (in off-white) for the exoskeleton instead of exposed steelwork, with the latter presenting issues in terms of steel connections and nodes, aesthetics, and requirements for fire and corrosion protection. This more costly option also however provided the pragmatic solution to visually align the exoskeleton with the glazing behind in free-form areas – essentially it would match the curvature of the glazing so the steel didn’t have to, and avoided the need for double-curved sections. Muscettola explains: “The front and back face of the cladding follow whatever the glazing does in terms of curvature. The other two sides follow whatever the structural members are doing.” She adds: “The good part is that the surfaces of the cladding are always singly curved.”

Software & collaboration

In 2008 ZHA principal Patrik Schumacher coined the term ‘parametric’ architecture to describe the practice’s vision of avoiding strict repetition, and instead pursuing the creation of more organic and free design forms with the help of software and algorithms. Although Morpheus is an experimental project in the luxury sector, in a highly competitive hotel environment where time is money there also needed to be a rigorous focus on efficient and quick solutions to ensure it met its three-year construction window, and software would be instrumental in this. The architects adapted existing 3D design tools to efficiently create the design of unique free-form areas on Morpheus, as Muscettola explains: “I don’t think this would even have been built 10 years ago. In terms of producing the amount of information, developing the design at the speed that we did would have been impossible without the use of 3D tools.” These included Grasshopper, Rhino and special plugins that ZHA created for this project with other companies. The entire project team needed to be highly motivated in order to complete all construction and fit-out of a pioneering project with such a range of complex geometry in under three years. Muscettola puts it simply: “They are not going to do what we ask them to do if you don’t have a good way of collaborating. While she says that the client was instrumental in this, having a “good technical team fully employed by them,” and being hands on all the way through the design and construction. She adds: “The vision from the client was brought all the way down to every consultant – the challenges were down to every fabricator, to find solutions that were outside the box.”

Interiors

While most hotels make do with a forecourt and canopy to welcome guests, the canopy here is the building itself, guests entering via the porte-cochere formed underneath. They are then dazzled by a 40 metre high atrium, where the external triangular structural motif is repeated in two spectacular feature walls framing the space. These are three-dimensional and formed in triangular metal sections (aluminium at ground level and GRG above), each formed of smaller, backlit triangles. Completing the composition is a roof formed by the exoskeleton wrapping the bottom internal face of the hotel’s first central void. Its symmetrical pattern of triangles adds to the kaleidoscopic overall effect, letting daylight stream in from above. The white marble floor’s pattern was also designed by ZHA, with yellow stone inlays to imply the circulation path guests will take. There is both a strong focus on the refinement of materials and design, and an intense sense of formal order – perhaps something of a contrast to the more free-form aspects of the exterior. The 21st floor ‘Yi’ restaurant, offering modern Chinese fare, is arguably the most dramatic internal space after the atrium. Sited on the bridge, the exoskeleton curves sharply over the space, but the interior has been designed to provide a contrasting level of intimacy. ‘Pods’ of tables are surrounded by sculptural screens, reflecting Chinese society’s habits of having private gatherings in separate rooms. Each screen is formed of hundreds of bronze-finished steel leaves, offering privacy (for example from the lifts passing nearby up the interior faces of the voids) while also allowing discreet views out and light in. Designed by ZHA, these impressive structures are simultaneously somewhat forbidding, and protective.

Conclusion

The client’s aim was to provide a hotel which would fully represent their ambitions as a major operator, and reach towards the future to distance Morpheus from its nearby competitors. Also, it provides a special place in itself for guests to remain, its very structure creating spectacular views where there were none. It’s also a true celebration of architectural geometry – one minute in an orderly, disciplined fashion in the atrium, and the next throwing away the rules externally. In its bold exuberance, Morpheus might have been something of a gamble for both client and architect, somewhat appropriate in Asia’s gaming capital. However due to a major team effort supporting the realisation of the design’s keen sense of pragmatism allied to playfulness, an architectural milestone has been reached. ZHA’s Muscetolla says close collaboration was a feature throughout this project, and was core to “a very smooth process” between client, architect and the rest of the project team. Delivering a groundbreaking hotel of this complexity at pace – without glaring crises – is, says the project director, a testimony to the “respect” and “open discussion” that characterised this job. As one of Zaha Hadid’s final projects, it’s also fitting that the building is a game-changer.