Article by UNStudio The 400,000-square-metre Raffles City development in Hangzhou, China is UNStudio’s largest single construction to date. To design this structure, we needed to develop an integrated design solution that could incorporate our scale and sustainability goals through Asian fabrication methods, while overcoming programmatic complexity, social constraints and economic restrictions.
“Raffles City Hangzhou…designed from the inside out.”
When starting a project as complex and as ambitious as Raffles City Hangzhou, it was important to establish our human and societal ambitions. Much more than an undulating shape, the parameters of this building were rooted in a human and programmatic level first and foremost, supported strategically by parametric design components. The human elements ultimately make or break the success of the building’s function and occupancy, and as such, each design element comes with a considered thought process, strategy and intention. In this way, Raffles City Hangzhou was designed from the inside out: accessibility, programmatic layering and interweaving, and interaction with the urban context determined the external geometry.
Image: Hufton + Crow
“A double height glazed podium facade…making it appear as though the building is floating above the landscape.”
Each tower has three main facade types: The urban facing facade, the tail facade and the landscape facade. The urban and tail facades lead towards the interior podium courtyards. The link between these two facades is the landscape facade, which begins at landscape level and elevates into four themed courtyards that flank the two towers. Apart from these three facades, a double height glazed podium facade wraps around the bottom of the building, providing access points at different scales and making it appear as though the building is floating above the landscape.
To design these facades, a dedicated team was assigned to each facade, equipped with its own strategy and chain of tools. Along the geometry development process, we worked intensely with a lot of internal and external collaborative expertise from programming and scripting specialists.
Image courtesy of UNStudio
“The facade fins…using half the material while achieving the same effect.”
As there are many different facade elements, we needed to be wary of a potentially fragmented appearance. To overcome this, we developed facade component motifs, such as a continuous framework of horizontal and vertical lines that enclose metallic fins and tiles. These components transform, grow and shrink in a controlled way across the envelope of the building, allowing each facade to serve particular functions. By analyzing the tower facade for exposure to radiation and heat, we were able to prioritize parts of the building that needed more shading in relation to its orientation. The facade fins, designed in a triangulated folding pattern, became a three dimensional object from one individual sheet of metal. An in-depth analysis of the shading depth, orientation of rotation of those fin, resulted in a reduction of required metal surfaces from eight square meters to four, using half the material while achieving the same effect. To accommodate different parameters, we used several different fin sizes. Some fins were wider on the bottom, or had a narrower surface. The fins are paired with a unitized curtain wall system across the urban facade to give the building its characteristic and performative texture.
“These parameters self-optimise during automated instantiation. This simplifies fabrication demands and reduces cost.”
