In conjunction with our recent coverage of the Xi’an International Horticultural Expo, we would like to share Aidan Flaherty’s interview with Holger Kehne, co-principle of Plasma Studio and GroundLab. Plasma Studio, GroundLab and LAUR Studio worked together to win this international competition with a 37-hectare master plan for the International Horticultural Expo, a 5,000SM Exhibition Hall, a 4,000SM Greenhouse, and a 3,500SM Gate Building. The project initiated the re-development of a large area between the airport and the center of the ancient city of Xi’an – known as the home of the Terracotta Army of the Qin Dynasty. The Expo opened in the spring of 2011 and welcomed more than 16 million visitors before it closed in the fall of 2011. The Expo park will remain as a new contemporary addition to the Xi’an region. The particularities of this legacy plan are currently underway. Holger Kehne discusses his firms’ unique design methodologies and multidisciplinary approach while working on this large-scale project. Read the interview after the break.
Please could you describe Plasma’s overall conceptual design for the master plan? H.K.: Our approach was to give an organic indexical appearance to this extremely artificial new landscape, to at the same time make it obvious in its artificiality but also emphasize the natural dynamic events that it contains, i.e., the flow of water, people. The project was conceived to be self-sustainable with the buildings integrated into the overall organization—an opportunity to project new organizational patterns that are fluid and gradual, instead of hierarchical and deterministic. What was it like to master plan and design for an expo—an old time event model that displayed industry advancements, promoted cultural exchange and developed a nation’s brand identity? How did your firm address this model through design? H.K.: Good point. The concept of an expo is indeed a curious and somewhat impossible mix of 19th century legacy and spirit with the ambitious content of showcasing “the future.” However, horticultural expos are distinct in that they have historically been used as instruments for initiating strategic large scale urban change and development. In my home country Germany, national horticultural expos are well known for their local themes and relevance—such as dealing with post-industrial brown-fields in the Ruhr. This is the case in Xi’an—we concentrated on bringing sustainable aspects to the forefront. At the same time, the sheer amount of people projected to visit—12 million over 6 months—was one of the most vital design cues, driving the overall plan’s character as a biomorphic rhizomatic distribution system.
Could you describe the sustainable elements used in the overall Expo as well as in The Greenhouse and the Creativity Pavilion? What sustainable elements did Plasma feel most strongly about incorporating? H.K.: It was vital to create a hydrological recycling system where water runoff is collected and cleaned naturally before being used for irrigation or discharged into the lake. We incorporated water basins with reed beds as part of the overall park layout and experience. The Greenhouse’s main sustainable strategy is its location within the ground. This location creates a constant condition from which, as in any botanic greenhouse, artificial conditioning has to specifically be done. The various climatic zones are located specifically where more or less solar gain/ground tempering occurs. Both the Creativity Pavilion and The Greenhouse are only performing their current function, as key features of the Horticultural Expo, for 6 months, so an appropriate strategy needs to be designed for the legacy that will come afterwards.
What are the most significant design features you included in the master plan, the Creativity Pavilion, The Greenhouse and the Guangyun Entrance? H.K.: The main master plan is derived from an analysis of people’s movements through the site and creating gradient distributions of density. The buildings are designed to be subservient to this overall system. The Guangyun Entrance has been designed to read and be experienced as the landscape itself—peeling off and bridging over the motorway. It is organized as three braids meant to separate the inflow and outflow traffic and the trellis structure is a further three-dimensionalizing of this complex braiding. Over time, as it becomes overgrown with vegetation, the Entrance will become a green tunnel. The Greenhouse’s integration into the hillside is significant for the building’s appearance as a semi-submerged crystal as well as the experience of the visitor—he has to enter through a prolonged cut in the ground and, as a result, the bright glazed interior has a different impact. It feels more like an extension of the ground rather than a clearly engineered structure or building. The Creativity Pavilion is also integrated within the braided field of paths—with two paths cutting through it as it extends like piers into the lake. The form of the building is similar to three distinct fingers that cantilever over the lake. Approaching the building, it is almost invisible, formlessly blending into the ground as a series of triangulated mounts. This anti-iconic appearance is counterintuitive to architectural history—where it is typically the front of the building that constitutes its strongest presence. So, in order to truly integrate the building within the landscape, we hid the Creativity Pavilion from the front by simply flipping it around. The rear elevation, which is seen only after one has passed the building from over the lake, becomes the iconic and identifiable structure, a series of cantilevered volumes that terminate as screens which aggressively engage with the act of observing and being observed. It is somehow fitting that one of the three arms is occupied by the local television company’s onsite studio. What was the design process like for the Guangyun Entrance? H.K.: At first we designed the building as a concrete tunnel that frames the view of the Expo site. However, the clients were unhappy with this scheme and they were right—the first design was not well integrated and a bit clumsy. Hence we redesigned it completely and came up with the more dynamic braided layout and a light trellis to be overgrown by plants. This idea of the structure offering a direct image of ‘horticulture’ to the visitors and traffic on the road beneath was convincing. For the canopy structure our vision was a tensegrity system. We worked with engineers from Arup and together we came up with a compelling system. However, real world constraints and Chinese regulations meant that it had to be changed into another less ambitious kind of structure but visually it still carries the same effect.
How did you find the design process for the Expo dissimilar from other projects? H.K.: We had an extremely short amount of time for a project that encompassed such a wide range and scale. At the time, the site itself was being completely remodeled, so we did not feel sufficiently equipped to relate to the local history and culture and we received little information regarding programs and activities. Therefore, it was within this vacuum that we endeavored to set forth a design framework with goals that would be as consistent as possible. That being said, it was very productive to work alongside a range of other experts and consultants and it was extremely comforting to see that everyone was pulling in the same direction. How is the site of the Expo intended to be used after the Expo closes? H.K.: We were told from the beginning that our part and all three buildings would remain as legacy. It will form a kind of central park for the new developments around it and the buildings will receive new functions. These are still to be determined. We hope that we will have the chance to be involved and able to complete them to their full potential whatever the program. We have already drafted a legacy plan for the landscape that replaces the existing planting with more performative/useful green spaces appropriate for the local climate and requiring little maintenance. Your firm has designed a number of projects in China. Are you still surprised at the rate of construction? Does this influence the design process? H.K.: I am still surprised. When we were visiting the site there was nothing. No hills, no lake, trees in other places than what was on the plans. Now it could not be more different. It is very impressive. Of course our design process needs to keep pace with these speeds, which is not always ideal but we have successfully adapted our working processes accordingly.
Please could you describe how you characterize the relationship between landscape design, architectural design and landscape urbanism? How does this relate to the Expo? Does it? H.K.: Landscape Urbanism is a relatively new hybrid discipline of organizing man-made environments through the sensibilities and toolsets derived from landscape in order to address dynamic changes, emergence and complex interactions that are essential but excluded from the way that traditional urbanism is procured. Although Landscape design is only one source and subject matter, this emancipation is giving it equal importance to urbanism and buildings. GroundLab and Plasma’s close collaboration is exploring a similar synthesis between landscape/urbanism and architecture. Xi’an is a good example for a non-hierarchical synergetic relationship that we hope is relevant to future developments.