Realising the ‘Pearl of the Orient’

The acoustically sealed retractable roof

The stadium’s unique roof structure includes a fixed section above the seating area and a retractable section over the pitch. Weighing nearly 4,800 tonnes, the retractable section of the roof operates on mechanisms similar to railway bogies with flangeless wheels, allowing it to open or close silently over about 30 minutes, changing the atmosphere and functionality completely.

Given the proximity of residential areas, it’s crucial that the roof effectively contains noise during late-night events such as concerts. To this end, the retractable roof incorporates a number of different seals around the perimeter, and utilises heavy cladding panels to damp low-frequency sounds.

The roof system, one of the world’s largest and heaviest of its kind, is supported by two pairs of bespoke orthogonal main trusses spanning from 150m to 180m, anchoring on four bearing-free reinforced concrete tower cores. The trusses are form-found using classical structural theory and optimised with advanced analytical methods to achieve an elegant and compact design that marries the stadium’s architecture while ensuring an optimal viewing experience for all spectators.

With building information modelling (BIM) fully adopted at the outset, the design of the roof steelwork has been modularised and rationalised for ease of fabrication, transportability and constructability, facilitating a fast-tracked construction schedule and minimising abortive works. All the main trusses were joint up on the ground, and lifted together in a single lift of 6,200t with four strand jacking towers into position.  The entire construction process was digitally visualised in advance to enhance installation accuracy and construction efficiency.

The elegant ‘Pearl of the Orient’ façade

The ‘Pearl of the Orient’ theme is perfectly captured by the stadium’s shimmering façade, composed of around 27,000 triangular aluminium panels with a Fluropon Kameleon Lightning Mist coating that changes into various pearlescent hues depending on the daylight intensity. An additional layer of Fluropon Clean was applied – this coating uses a proprietary hydrophilic technology that causes rainwater to spread across the panels, allowing dirt or pollution to be naturally washed away.

At night, dynamic light shows transform the stadium into a dazzling spectacle against Hong Kong’s night sky. Our façade and lighting designers worked closely to realise this captivating effect. Thorough visual analyses were conducted to strategically position light fittings across the façade, tailor-made to enhance the stadium’s grandeur, considering its height and scale, while reducing sky glow to minimise light pollution. This seamless collaboration and meticulous planning and execution resulted in a façade that is not only visually stunning but also aligns with sustainability goals.

To achieve the light, ‘floating’ appearance of the ‘pearl’, our structural and MEP engineers collaborated on designing a compact, cantilevered steel-reinforced concrete structure. The ventilation louvers were carefully concealed inside a multi-functional trench surrounding the roof. The design supports the visual impact while ensuring structural integrity and functionality.

Spectator comfort 

Our design prioritises user experience, ensuring an enjoyable experience for spectators. The seating bowl, constructed from over 2,000 precast units, features individual cooling outlets beneath each seat, optimising both spectator comfort and energy use. We conducted extensive airflow modelling to ensure adequate coverage throughout the stadium. We also performed sophisticated computer analyses to verify that the vibration comfort of spectators meets international performance-based criteria for concert and sports event scenarios.

The stadium bowl is equipped with pitch cooling to maintain a comfortable environment for floor audiences without cold drafts, and to ensure safe temperatures for players during sporting events.

Our sophisticated acoustic design optimises sound quality and environmental sensitivity, creating an immersive auditory experience during events.

The sports lighting system, mainly designed for football and rugby games, provides an exceptional visual experience for both live spectators and broadcast viewers. Strategically placed primarily along the roof perimeter, the lighting setup offers clear visibility of both players and the ball, reduces glare, and ensures uniform illumination across the field. For broadcasts, the system achieves a brightness of 2,000 lux, essential for capturing high-quality footage, with careful placement to avoid any lighting behind goals and maintain the best angles for comprehensive coverage.

The transformable stage

The stadium features an innovative ‘stage pocket’ system at the southern end of the lower tier, a first in Hong Kong and one of the largest globally. The system incorporates a section of seating that hinges upwards, creating space for concert stages and increasing the venue’s capacity for large events.

The system consists of four modular units: two central large units and two smaller side units. These can be operated independently, providing flexibility depending on the size and requirements of the event. The ‘stage pocket’ lifts into place using large hydraulic rams, securely locking once in position with the concert stage typically constructed directly in front.

This design not only simplifies stage setup by providing direct access from the vehicle loading dock to the stage area, facilitating efficient equipment transport, but also minimises damage to the turf. Furthermore, fewer seats need to be removed during event setups, streamlining the process and reducing preparation time. This ingenuous engineering enhances both the functionality of the stadium and the overall concert-going experience.

Sustainability as a priority

From its inception, sustainability has been a cornerstone of the stadium design. Over 10% of the roof area is equipped with photovoltaic panels, harnessing solar energy to power the facility. This is complemented by a comprehensive rainwater recycling system that conserves water and manages stormwater runoff, using it for irrigation purposes.

Additionally, the stadium’s air conditioning system is powered by the Kai Tak district cooling system, which is significantly more efficient than traditional systems. By using chilled water, it consumes approximately 35% less electricity than conventional air-cooled systems.

Multi-trade integrated mechanical, electrical and plumbing (MiMEP) and design for manufacture and assembly (DfMA) were widely adopted throughout the course of design and construction. By standardising equipment and services distribution for a modular design, the project reduces waste and carbon emissions, and accelerates the installation speed.   

Safety

The venue boasts a pioneering fire engineering design equipped with an addressable fire detection system. This system precisely identifies fire locations, enabling rapid response. Integrated with remotely operated fire monitors – also a first in Hong Kong, it can target specific areas with water, quickly controlling and extinguishing fires. This proactive fire safety system minimises risks to both attendees and the structure itself, offering a new approach for fire safety in public spaces.

Addressing the challenges of ingress and egress by a large crowd, our transport consultants conducted extensive 3D MassMotion simulations to understand different behavioural patterns under various scenarios, taking into account the mobility speeds and capabilities of diverse groups. This analysis was instrumental in designing efficient crowd dispersal routes, particularly considering noise implications at night, ensuring a smooth experience for all visitors before and after events.  Pedestrian access to the stadium is strategically located at the podium level, allowing visitors to traverse without crossing busy roads.