Situated at the heart of Hong Kong Island’s commercial center, the Tai Kwun Center for Heritage and Arts serves as an architectural metaphor of a regime transition. Here, the shift concerns the reconfiguration of a formidable monument from Hong Kong’s 19th-century colonial past into a liberated cultural nexus. Originally an intimidating complex that housed a prison, police station, and magistracy, Tai Kwun is now an open and welcoming center for arts and culture.
Working in collaboration with British conservation firm Purcell, Herzog & de Meuron executed the intricate adaptive reuse project over 12 years. The result, finished in 2018, is indicative of the Basel, Switzerland–based firm’s skill in integrating the old with the new, simultaneously preserving existing elements while incorporating contemporary structures that are at once radically novel and historically compatible.
Herzog & de Meuron senior partner and project lead Ascan Mergenthaler recently shared his firm’s strategy to negotiate this architectural transformation in terms of material details.
Brownell: Like Herzog & de Meuron's Elbphilharmonie Concert Hall in Hamburg, Germany, or the Walker Art Center in Minneapolis, the careful conservation of the Tai Kwun Center is paired with new additions—yet the overall experience remains cohesive. How do you achieve this kind of approach?
Mergenthaler: We carefully study what is there, what can be saved and reused, what makes sense to be incorporated. It’s the opposite of a clean slate, and we allowed the existing to inform and inspire our conceptual thinking and the design process. While we try to keep as much as possible from the existing fabric, we use the newly built to complement and improve the old, thus making it stronger. This is the idea of revitalization, which goes beyond the mere built environment, where it is also necessary to think this through on a programmatic level. Only then can a building or building complex be successfully reactivated. In this context, it is important that the newly built, although it is informed by the existing, clearly states that it is of today and not a reconstruction or simulation of the past.
The project description reveals that the aluminum-cast modules on the façade the were inspired by masonry construction. Why did you decide on this material?
Aluminum seemed to be the correct choice for many reasons. It is solid with a physical presence, like brick or stone. But it is much lighter, malleable, recyclable, and easy to control in the manufacturing process. This versatility allowed us to optimally engineer and precisely manufacture aluminum blocks that achieve the required technical performance.
Together, the overall system acts as a heat sink and a sun- and rainscreen; obscures the mechanical equipment; and is porous enough to allow adequate air circulation and views to the outside when desired. Its tactile and porous surface is designed to be experienced from both the inside and outside. On the outside, the textured surface helps to reduce reflectivity and glare during the daytime. And at night, light emitted from the building will be partially screened, expressing the life of the activities within without creating heavy light pollution. Lastly, we liked the fact that the raw material consists entirely of aluminum obtained from recycled car alloy wheels.
Why cast the modules?
We liked the roughness of the casting process. The units are crafted like masonry blocks or bricks—they have this inherent physical material quality that we could never achieve with folded sheet metal, for example. The blocks establish a dialogue with the surrounding, historically significant prison walls with their large granite blocks, yet they are still much lighter and able to fulfill the performance needs of the two new buildings.
Given a chance to create new buildings in contrast with old masonry structures, architects might first conceive light and airy glass façades. Why did you choose not pursue this approach?
A glass façade was never an option. It would have been too similar to surrounding office towers and would not have been a practical envelope for the given cultural program—a multipurpose auditorium and large art gallery spaces. We were convinced that the overall character of the site has to be respected, and although the compound is now a place for public and cultural life, it should never neglect its history and past. Lastly, in this climate, glass façades are very difficult in terms of energy consumption and glare.
The project has one of the most intriguing examples of corner-turning I have seen in architecture and must have involved countless hours of development. Why such an investment in this particular project, and what did you hope to achieve?
The interlocking aspect of this detail is crucial. Corners are important moments in a façade. Rather than simply solving it with a miter, where the two façades would be literally cut into two separate planes, we were much more interested in “knitting” the façade around the corner, to strengthen the corner rather than weakening it. The actual cut of each block had to react to the geometry of the adjacent block, which resulted in an interesting, irregular cutting line.
But it was also impossible to match the geometries of the two adjacent blocks completely and this slight imperfection makes the corner even stronger. It adds an aspect of craftsmanship and likeness to historic buildings where corners are often also treated in a special way.
The computer makes these solutions relatively straightforward, and why not use the advantages of a CAD/CAM production process if it ultimately results in a more interesting detail? Details like this sit at the crossroad of analog and digital, something we are very much interested in.
The Tai Kwun Center is an essay in reversals: a former prison yard turned into a free cultural zone, an old landmark on a hill turned into a low-lying development with valuable open space. For you, what does the project represent for the future of Hong Kong?
The Tai Kwun Center for Heritage and Arts is a civic icon very much representing the values of present-day Hong Kong. A city within the city, with a program that ranges from dining and shopping to performing, screening, and exhibiting. It is open and inviting for everybody—literally an oasis in the heart of a bustling city, inviting exchange, education, engagement, and decompression at the same time—something that didn’t exist in this density in Hong Kong before.
This interview has been edited and condensed for clarity.