gooood would dig into projects which are appropriate for deeper report, in order to present the project in a more comprehensive way. In this episode, we interviewed Atelier Z+ for their project Wetland Research and Education Center inDongtan, Chongming, Shanghai. More: Atelier Z+ on gooood
出品人：向玲 | Producer: Xiang Ling
编辑：陈诺嘉，武晨曦，李诗蓉，周诗若，王玥莹 | Editor: Chen Nuojia, Wu Chenxi, Zhou Shiruo, Li Shirong, Wang Yueying
▼项目外观，external view of the project ©陈颢
Q&A with Atelier Z+
（Please scroll to the end of the article to see the English Q&A)
Background and Strategy
“The Research and Education Center was destined to be built on the reserved wetland.”
▼项目鸟瞰，位于湿地中，aerial view of the project located in the middle of the wetland ©陈颢
▼总平面图，项目位于湿地中，以栈道与海堤连接，master plan, the project is located on the wetland, connected to the seawall ©致正建筑工作室
▼工作模型，建筑布局，working model studying the layout of the buildings ©致正建筑工作室
▼施工现场，建造时基地尚未疏浚，the site was not dredged until the construction was finished ©陈颢
▼建筑如同浮在水面上，the building looks like floating on the water ©陈颢
▼建筑之间通过栈桥连接，the houses are connected by trestles ©陈颢
▼主楼外观，external view of the main building ©陈颢
▼从食堂看向主楼，view from the canteen to the main house ©陈颢
▼从主楼看向其他辅助楼，出檐帮助遮阳，view to the other buildings from the main building, cantilevered roof providing shadows to the space ©陈颢
“The project was started from an abstract and strategic consideration.”
▼概念草图，design concept ©致正建筑工作室
▼体块生成，generation diagram ©致正建筑工作室
▼工作模型，working model ©致正建筑工作室
▼Y型结构下方形成小屋，上方形成山谷，Y-shaped roof creating covered space below and valley space above ©陈颢
“We formed a sense of dimension by covering the space and created understanding of the site through the visual communications between different houses.”
▼建筑间的对望形成尺度感，visual communications between the houses creating a sense of dimension ©陈颢
▼屋顶形成对景观视线的限定，roof framing the landscape ©陈颢
▼传统园林空间，traditional Chinese garden spaces ©（左）CreatAR Images，（右）致正建筑工作室
（左）留园入口，弯曲的廊子，(left) entrance of Lingering Garden
（右）延光阁，在稳定空间中静观外部景色，(right) Yanguang Pavilion, looking at the outside scenery in a stable space
▼明暗交替的空间，space with changes of light and shadow ©陈颢
Y-shaped Structure and the Space
“We hoped to design a space where people could make their own choices and hide the architecture behind the subjectivity of the users.”
▼结构分解轴测图，exploded axonometric of the structure ©致正建筑工作室
▼十字截面的柱子更具尺度感，cross-section columns providing more sense of dimension ©陈颢
▼Y型结构在室内形成让人可以停留的空间，Y-shaped structure creating space for people to stay in the interior ©陈颢
▼项目远景，如同一片Y型结构落在水面上，distanced view of the project like Y-shaped structures landing on the wetland ©陈颢
▼从海堤边看向主建筑东立面，view of the east facade of the main building from the sea wall ©陈颢
▼从栈桥上看研究栋北立面，view of the north facade of the research building from the trestle ©陈颢
“It was not necessary to pursue lightness in the structure itself. The large cantilevers created lightness in the broad sense.”
▼巨大的混凝土屋顶没有梁，表面木纹提供了某种尺度感，the concrete roof is flat without beams, the wooden texture providing some sense of dimension ©陈颢
▼屋脊部位的打开令其更向天空延展和开放，the open ridge making the structure extending towards the sky, creating a more open atmosphere ©陈颢
▼室内墙面采用翻新后的回收木模板，renewed recycled wooden panels are used for the interior walls ©陈颢
▼木纹混凝土细部，closer view to the wooden textured concrete ©陈颢
▼由于不存在明显的水平浇筑接缝，所以可以容忍一定混凝土色差以应对不可控的施工条件，as there is no obvious horizontal connections, the differences in the color of the concrete could be tolerated at a certain level, coping with the uncontrollable construction conditions ©陈颢
Design and the eco-environment
▼屋顶花园与湿地连成一体，the roof garden become an extension of the reeds in the wetland ©陈颢
“The project was a carrier for a particular human-land relationship.”
▼混凝土与玻璃节点详图，detail of the joints between the concrete and the glass facade ©致正建筑工作室
▼施工现场照片，construction site ©陈颢
▼玻璃立面外设置格栅以防止鸟撞，blades installed outside the glass facade to prevent birds from colliding ©陈颢
▼建筑与湿地，architecture and the wetland ©陈颢
▼鸟类在格栅上筑巢，birds nesting on the blades ©致正建筑工作室
Experience and Expectation
“Conspire with the future in an environment full of contradictions and uncertainties.”
▼项目将成为探讨湿地问题的平台，the project will be a platform to discuss wetland issues ©陈颢
More about Wetland Research and Education Center, Dongtan, Chongming, Shanghai
Located at the easternmost point of Chongming Island, at the mouth of the Yangtze River, Dongtan Wetland is a sort of estuary tidal flat wetland. This wetland sits on the middle of “East Asia – Australia” route which is known as one of the eight migration routes for birds of the world. As a very important migration corridor for waterfowl in the Asian-Pacific region, Dongtan Wetland also becomes one of the most significant gathering places and habitats for wild birds. In the 1990s, an invasive plant spartina alterniflora was introduced to reinforce the tidal flat, which then result in the ecological deterioration of the wetland. To deal with the issue, Shanghai Chongming Dongtan National Nature Reserve started ecological control on spartina alterniflora and environment optimization of bird habitats in 2013. The whole project was completed in 2019. As a supporting facility of this project, the Research and Education Center was built as an important platform of scientific research monitoring, bird banding, law enforcement of management and protection, science education. Besides, it serve for raising both awareness and display of ecological and environmental protection as well as promoting worldwide cooperation and exchange.
▼项目鸟瞰，aerial view of the project ©陈颢
The site is situated in a restored reed wetland in the northeast of the Nature Reserve, where the water and the sky merge in one colour, few people tread, flocks of birds perch. With modesty and respect, we suppose the building would be in harmony with the natural area. The inspiration is from secluded shacks scattering between the mountains and waters, which described by the ancient Chinese landscape painter Wang Meng in fourteenth century. With the intention of minimizing the impact on the local ecosystem whenever this place is under construction or in use, the architectural volume is divided and scattered, forming a group of settlements above the pile platform, floating on the water and hidden among the reeds. Five buildings of different volume including the conference and exhibition, the canteen, the research, and the dormitory are cross-connected by a zigzag trestle bridge. Through the conversion of prototype and the control of scale, the atmosphere of indoor and outdoor spaces could be in response to the environment specificity such as sky, wetland, reeds and flying birds. Enlightened by the “shack with double pitched roof” in Wang Meng’s painting, we turned the double pitched roof over, made a “Y-shape” cantilever structure, juxtaposed these two “Y-shape” independent units and created a new double Y shape space (YY). This creative idea has brought this prototype new spatial meaning. Firstly, the space covered by these two Y-shape structures is given a sense of shelter and created a fixed horizontal vision towards the vast wetland, while the openness of ridge is made extend towards sky. Secondly, the counter-slope space above the roof offers the feeling of living in a micro-valley, where visitors can enjoy the cropping and re-composition of broader horizontal vision. Moreover, compared with the veranda of lateral eaves gallery of the double pitched roof prototype, the veranda of the new structure has the space firstly pressing down and then lifting up, creating the feeling of opening to the environment.
the painting of Juqu Forest House
▼项目远景，位于湿地中，distanced view of the project located in the middle of the wetland ©陈颢
▼栈桥连接建筑，trestle connecting the houses ©陈颢
With a series of juxtapositions and variations of Y-shape unit structure, we designed a series of continuous saw-tooth roofs and created covered spaces with scale difference where multi-functional programs are available. With the organization of circulation, distribution of courtyards, variation of transparency of enclosures, differentiation of structural span and height, and the combination of ridge skylights and clerestories, there is none clear boundary between different functional spaces, peoples are encouraged to use them in a flexible way. Besides, this special linear pattern of space organization has brought unique indoor experience between in-position view and in-motion view. When staying in a certain space unit, peoples are able to enjoy a body-enveloping experience under the roof with the view parallel to the structural unit, and the external natural scenery in front of the eye; while walking through different space units, with the rhythm of variation in height and light, they will feel as walking in a garden-courtyard house. This unique experience is strongly intensified on the roof of conference & exhibition building: In response to the site features, we have evocated a flashback interpretation through alternating and combining the distant eye-level view of wetland from the “valley” on the roof and the close overlooking view of indoor scene from the skywalk under the roof. The scattered building volumes are fragmented by the overhanging saw-tooth roofs with deep eave which successfully eliminate the scale difference between buildings, and also are blurred by overlapped deep shadows and reflection above the water.
▼V型结构形成山谷式的屋顶空间，V-shaped structure creating valley-like roof space ©陈颢
▼明暗交替的室内空间，interior space with changes of light and shadow ©陈颢
▼从屋顶看向湿地，view to the wetland from the rooftop ©陈颢
Considering that weather-proof and maintenance of this facility are quit challenging work in high humidity and salinity conditions, the light steel or wooden structure was abandoned in our design. Instead, reinforced concrete is selected to build with the simplicity of tectonics. Building A, B, C were built by Y-shaped cantilevered reinforced concrete bent frame structure with crisscross section and partial folded-plate. Among these buildings, the cantilever of building A was so large that the whole structure had to be constructed by steel reinforced concrete and the exhibition hall was partly designed with steel mezzanine; building D and E were constructed with concrete folded-plate structure. In order to expose the crudeness from the concrete structure in wetland, long pine timber formworks were used in the as-cast-finish concrete construction to obtain natural wood texture. The non-structural enclosure and partition walls were also coated with refurbished recycled timber formworks to unify the material expression. Since sheltered from long overhang eaves, bird-friendly floor-to-ceiling windows with vertical grilles which provide the visitors maximum of field view are used for most external envelop. The trestle bridge and the water platform were paved with precast concrete battens with crack left between each other, which not only enhanced the feeling of walking over water but also made room for reed growth. Moreover, all the “valleys” bottom on the roof were covered with slightly undulating soil and low-maintenance planted miscanthus and shurbs. For the purpose of environment integration and sustainable recycling in the future, all the pitched roofs which trimmed with titanium-zinc sheet were covered with indigenous reed straw reaped and processed under the supervision of local experienced reed weavers.
▼主建筑立面图，elevation of the main building ©致正建筑工作室
▼剖透视 – 会议展览栋，perspective section – conference and exhibition building ©致正建筑工作室
▼剖透视 – 食堂栋，perspective section – dining building ©致正建筑工作室
▼剖透视 – 研究栋，perspective section – research building ©致正建筑工作室
▼剖透视 – 宿舍栋，perspective section – dormitory building ©致正建筑工作室
▼节点细部，joint detail ©致正建筑工作室
项目设计 & 完成年份: 2013-2019
主创及设计团队: 周 蔚(主创)，张 斌(主创)，金燕琳（方案设计、扩初设计、施工图设计），徐 跃（施工配合），李姿娜，胡丽瑶，刘 昱，张雅楠，孙嘉秋，薛楚金
建筑面积: 4,092 ㎡
Project name：Wetland Research and Education Center, Dongtan, Chongming, Shanghai
Design year & Completion Year：2013-2019
Leader designer & Team：ZHOU Wei, ZHANG Bin, JIN Yanlin(Schematic Design, Developing Design, & Construction Design), XU Yue(Construction Coordination) , LIU Yu, HU Liyao, LIU Yi, ZHANG Yanan, SUN Jiaqiu, XUE Chujin
Structure Consultant: ZHANG Zhun (AND Office)
Project location：Shanghai Chongming Dngtan National Nature Reserve
Gross Built Area (square meters)：4,092 ㎡
Photo credits：CHEN Hao
Partners：Shanghai Investigation, Design & Research Institute Co., Ltd.
Clients：Management Office of Shanghai Chongming Dongtan National Nature Reserve
1. How did you choose the site for the project? Why was it on the wetland? How could the architecture respond to natural changes such as the tides?
Dongtan Wetland Research and Education Center was not an isolated architectural project, but an integral part of the restoration project of Dongtan in Chongming. Dongtan is a tidal-flat wetland located at the estuary of Yangtze River and has been growing eastward continuously for about one kilometer every ten years, creating lines of seawalls among which people would cultivate the land for agriculture. As Dongtan is at the intersection of fresh water and salt water, providing a necessary place for the migration of Asia-Pacific migratory birds, it has generally become a bird sanctuary. In the 1980s, a species called spartina alterniflora was introduced to stabilize the tide flat. Unexpectedly, this plant was too fast growing and has no natural enemy, so it quickly overgrew the entire mudflat, resulting in the degradation of the wetland and the loss of a place for birds to settle. In 2013, Shanghai Municipal Bureau of Landscaping inaugurated a wetland restoration project, aiming to eradicate the spartina alterniflora and restore the wetland. The way to do this was to enclose a new seawall on Dongtan wetland to cut out the spartina alterniflora and fill it with seawater, then dredge it after a few months to reform the terrain with reeds and shoal. The scope of the project is over 20 square kilometers, and after the wetland is restored, a research and academic hub will be established to display the history of the restoration and also provide a platform for organized public educational events.
The Research and Education Center was destined to be built on the reserved wetland. When we first worked on the project, the restoration work had not started yet, with only a demonstration area made on the south part of the site. We had no clue for what the final environment would be like, or how the reed shoal and the water would be distributed in the site. According to the masterplan, we chose the turning corner of the seawall as the final site. Beyond the corner, the seawall folds to the northwest and the depth of the wetland will gradually decrease. If the building is moved northward, it will be too close to the existing sea walls. If it is moved southward, it would be surrounded by an open and homogeneous environment. We could only arrive at the old sea wall on the inner side when we were doing the site survey, which was 1 km away from the site we had chosen from the satellite map. Though after the restoration, the landscape was still only a future expectation. As the wetland was enclosed by sea walls, it would not be affected by the natural tide and the water level changes by probably only a few tens of centimeters. The building was constructed on a platform supported by piles and the lower limb of its concrete edge was right at the highest water level. The construction area will not be dredged until the platform and other main structures are completed, then the water will be let in and the overall restoration of the wetland will be carried out, resulting in a building looked as if floating on the water.
2. Who are the users of the project? What was the programme of the building and how are wastes from use discharged?
The project consists of five buildings. The main building is for conference and exhibition, which contains a multifunctional hall and a permanent exhibition hall that can host science and research meetings and public education activities. Together with the multifunctional hall, we also designed a café where people could take a rest during meetings. The canteen is located in another building, including three dining areas, one of which is larger in size with a capacity of about 20 people. It could also be used as a meeting place. The canteen would only come into service when needed for seminars or public education activities. Generally, semi-manufactured food is delivered to the kitchen for cooking, leaving out the rough processing.The research building is a work space for onsite researchers, providing a large space that and is equivalent to two offices. There are two additional dormitories designed for the researches to stay.
The conservation area is very strictly managed and the visitors need to make an appointment before entering. There are three main types of users of the building: the first is science researchers who will do field observations, bird banding and study the tide and creatures on the wetland; the second type of users are professionals and leaders from relevant industry and administrations who come for inspection or exhibitions; the third type is the general public who can have a visit by appointment and directly participate in the public education of environment and bird protection.
Waste disposal is a really sensitive issue in protected areas. The building area is about three to four thousand square meters and needs to address issues of water supply and drainage, energy and air conditioning. There are water supply tubes embedded in the sea walls. For the drainage, we proposed to partly treat the waste water through arrangement of plants. However, this proposal was adopted due to the difficulty of implementation. In the end, we placed a septic-tank. The sewage would be treated and discharged directly into the wetlands when it is up to standard. The waste in the septic tank would be cleaned periodically by specialists. We had considered using a ground source or water source heat pump system for air conditioning in the early stages, However, although the system would save the operating costs after construction, the client felt that the amount of work involved in drilling the well was too large and not necessarily suitable for the wetland environment. Thus the solution was replaced by using a relatively mature multi-unit conditioning system that allowed each zone to be controlled separately without causing significant consumption. The entire building façade is transparent, with efficient shading due to the large eaves of the roof. Generally speaking, as high-tech environmental protection methods were very challenging to the client and it was hard to avoid performance degradation, only conventional techniques were used in the construction of the project.
3. How did you start the architectural design after the site was decided?
The starting point of this project could not be simply defined as a plan, a section or a concrete form in a traditional sense. The project was started from an abstract and strategic consideration. Because the environment in which the project was situated is unformed, and the surrounding area was empty and largely devoid of scale, it was not possible to use environmental conditions as a guide. The climate was not favorable, where the wind was strong and the air was salty and humid In the beginning, when we were discussing the structure of the project with the client, they indicated that light-type structure was hard to maintain under such environment. This problem was reflected by the wooden-structural houses in the demonstration plot. In an environment with wide variations in temperature and humidity, wooden structure are prone to cracking and steel structures are likely to rust. Therefore, the client wanted to build a reinforced concrete structure which would be relatively strong and durable. This was just what we had expected.
The design came from our understanding of the site. We need to imagine what an artificially restored wetland would look like. What would people feel in the new building? It is a sanctuary built for birds where humans are occupying in a small scale. Therefore, the overall environment was not designed to be inhospitable, but with an atmosphere of wilderness. We hoped that we could design something that was like landing in the wetlands, responding to the quality of the site. It was an opportunity to discuss some issues that we had been engaging with for a long time. Personally, I have been continuous inspired by Wang Meng’s painting Juqu Forest House.I grew up in the regions south of Yangtze River, and its habitat is the product of a millennia-long coexistence of man and nature, allowing people to have a certain sense of stability associated with the understanding of the nature in Chinese culture. It was not about to defeat the nature or to submit to it. Chinese people have the intelligence to find their own sense of scale, stability and existence in the nature. In Juqu Forest House, Wang Meng depicted a place named Forest House Cave in the western hills of Taihu Lake, where there were natural caves where people used to live in seclusion before the Yuan Dynasty. They built straw huts by the water between the valleys to beside the lake and gained a peaceful existence among nature to introspectively thinking on themselves. It reflects the appeal of the elites in ancient China to escape from the society. Wang Meng’s narrative of nature was kind of hideous, dense and terrifying, making the sense of stability brought by the straw huts all the more prominent.
Returning to the project in Dongtan, the site itself had something unknown and we reflected the concept of “two faces in one volume”in this project. My understanding of the Chinese way of being in nature has two basic points, which have been discussed in the Shanshui culture throughout the history. Firstly, people tend to live in a valley because their topography provides some kind of shelter. Secondly, people tend to find stability in a small house with a double-pitched roof. The concept of the project reflects the fact that humans can relate themselves to the whole world with just a small grass hall, rather than a very large field. These two points are about physical sense of human body which can be understood even by non-experts. As our project was located on a flat site with no sense of scales, we had to reflect these features through our own creation. We reversed the double-pitched roof of the prototype and stitched the reversed roofs together to create a new house with open ridges. It created an interior space with different heights and a valley-like space on the reversed roof, providing a manmade image of the valleys. The plans and sections were decided simultaneously. The client was not sensitive to the functions of the spaces and they would often change their requirements during the design. In the face of this uncertainty, we designed spaces that are both defined and able to reorganize. The use of the Y-shaped structure was both repeated and changing in span, height and cantilever size, accommodating different spaces with different scales. These units can be divided or combined, and at the same time creating some circulation spaces in between.
The roof of the conference and exhibition building was composed of a line of small valleys and was accessible. Before the house was built, people have no sense of the scale of the site. The views were all the same in different distances. We formed a sense of dimension by covering the space and created understanding of the site through the visual connection between different houses. People on the roofs could have a partial view of the wetland which was trimmed by the valleys, generating a feeling of focusing. From some valleys you could see the seawalls and from other valleys the plank road was in your sight. Wild thatch and flowers were planted in the valleys. Plants in the valleys, the reed roof and the reeds growing in the wetland visually connected together, creating a new dimension to understand the place. When people went from one valley to another, they had to go through the upper part of the interior space, where they could overlook the activities in the building, enhancing the connection between the architecture and its environment. This tour also reflected the characteristics of traditional Chinese gardens because it was a process of it is a process of combining movement and stillness. People could stay in the valleys to enjoy the scenery of trimmed wetland. They could also experience the change of light when traversing the landscape. It was similar to the experience in a traditional Chinese garden or a house in the regions south of the Yangtze River, where there were light wells arranged in sequence, creating alternating light and shadow. The experience in the interior space was created by the same method as on the roof. The space consisted of units arranged in series. People could walk back and forth between the units or could observe the endless wetland outside from one of the units, with the skylight forming the change of brightness while giving tension to the spatial experience.
Professor Zhang Li from Tsinghua University was originally commissioned to be the curator of the Chinese Pavilion for Venice Biennale this year. He was contacting with a group of architects and asked each of them to make a video to discuss the relationship between human and courtyard. One example that I could recall is the entrance space of the Lingering Garden. Entering from the side door, people will pass through a winding corridor with a sequence of light wells bringing fascinating light and shadow effects. The other example is the Peony Study in the Master of the Nets Garden or the Yanguang Pavilion in the Garden of Cultivation. They are all stable spaces in a garden where one can stay for a while and enjoy a tranquil view of the external garden. The design concept of Dongtan project was based on these two kinds of experience, which transcends the shape and ends up in a conceptual, encompassing gesture. Through this construction, I hoped to prompt people to think about and understand their role and position in an environment that is not completely controlled by human beings.
4. On which stage did you begin to think of structure? Why did you use this type of structure to shape the space? What are the characteristics of spaces that were shaped in such a way?
As soon as we came up with the idea of reversing the double pitch roofs, we immediately asked our structural consultant Prof. Zhang Zhun to join in our team. The consideration in structure went along with the design in its early stage. The building was designed to have a concrete structure with a span of more than ten meters. My design intention was to minimize the use of supporting components. The structure was heavy, but people feel free and relaxed within it. It was about integrated physical feelings and reducing supporting elements could help to achieving this goal. The use of cross-sectioned columns was proposed by Prof. Zhang Zhun. If square columns were used, according to calculations, the surface of the section might need to be over one square meter, which would be slightly crude. Prof. Zhang also suggested that since the moment of inertia of the columns would not rest on the four corners, they could be cut out to form cross-shaped ones. Although the outer dimensions of the cross-shaped columns would be larger than the square ones, they seemed to have more lines and layers, somewhat like a Gothic beam-column, providing a series of notches that could be touched and felt for a greater sense of scale.
In many of our projects, we start to discuss structural issues at the beginning of the process. However, I am not an architect focusing on structural effects. In my perspective, structure should balance the intention of the design and the characteristics of the project. In Dongtan project, I intended to cover the building with a heavy structure to create a space that gives people a sense of freedom. If we use slender and denser columns to support the same V-shaped roof, the structural presence might be stronger. Now with such a structure, there is a great deal of freedom and people are free to choose where they want to stay. People sometimes feel confused in a particularly large scale space. Although the conference and exhibition building has an area of about 2000 square meters, it is composed of several units with a controlled sense of scale, providing plenty of room for people to stay. The challenge I was facing was to shape a space with a heavy structure that offered enough freedom, rather than delivering a monolithic design intention, which would regulate the users’ behavior. We hoped to design a space where people could make their own choices and hide the architecture behind the subjectivity of the users.
5. How was the structural scale shift determined? How did it respond to the ambiance of indoor and outdoor spaces?
The use of variant unit splicing in our design was partly dominated by the initial design intent, but also responded to environmental sensitivities. The project covered an area of 5000 m² and an interior area of about 4000 m², of which the scale was relatively large. To build such a large volume in a bird sanctuary was an interrogation to the design strategy. Our response was to conceal the scale of the building as much as possible. When you look at the architecture on the levee from a distance, you can find a series of Y-shaped structures that look like a flock of big birds landing in the wetland, which is from a non-technical interpretation. When you reach the trestle connecting the buildings, the first thing that comes into your view is the east façade of the main building, which is the side face of one unit. The reversed roof is supported by columns and it’s hard to figure out its dimension. Walking along the trestle, the north façade of the main building gradually shows up. It is composed of nine units varying in size and height, hidden in the shadow of the large cantilevered roof and separated from each other, creating something conflicting and ambiguous. At the end of the trestle, you arrive at the west side of the main building and you will realize that the scale of the construction is not that small. When you enter the building from the south entrance, you will find a space with dynamic scales. As the scale of the building is changing all the time, one can understand the relationship between human and space through different scales. It was a successful part in this project to use simple transformation and repetition to realize the ambiguity and redefine the architectural scale.
6. How could the design of the roof reflect the idea of sustainability? What effect will it have on the birds and other creatures? How do you maintain the roof?
Covering the roof with plants was an idea that was decided upon before the house was even formed. We used reinforced concrete to cast a huge set of structures and the roof turned out to be a particularly sensitive subject. How to make such a large roof concealed? The geometric outline of the roof will be visible from a distance and will not be a burden to the senses. However, when people climbed onto the roof, we wanted them to have a feeling that is not purely geometric. To achieve this goal, we adopted two methods. Firstly, we mulched the bottom of the roof valley with earth and planted some non-maintenance plants that people could walk on. The appearance of the plants would change with the seasons, flourishing in spring and summer and getting withered in autumn and winter, in keeping with the reeds in the wetland. Secondly, we covered the sloped roof with reeds. I could not accept the huge concrete roof to be exposed. Due to the high humidity of the environment, ordinary aluminum panels could not last long, and other man-made materials were too expensive to apply. Phragmites australis, which are abundant around the site, are sturdier than freshwater reeds, making them suitable for a straw roof. What’s more, this material is locally sourced and is able to be manufactured by local reed weavers. Straw roofs have a lifespan and need to be replaced after about five years, a turnover that architects and homeowners agree on. We did not look for a permanent solution, and such a replacement of the roof allows the building to have a relationship with the environment, which reflects a certain simplicity of sustainable thinking.
7. How could you make a concrete structure look lighter? What was the difference between wood formwork on the inside and outside surfaces of the concrete structure? What was your consideration on color, quality and texture?
The structure of the building mainly influenced the perception of people below the roof. A sort of simulated natural effect was created above the roof, while below it we provided a completely artificial interface. We wanted the underside of the structure to be flat from the start without exposing the beams. Some of the V-shaped roofs are very close to the ground at their base, and the closest concrete roof structure in the research building is only 1.5 meters from the ground, which is a deliberate attempt to create the feeling of drilling through. People would feel a huge, abstract, and continuous undulating interface while the natural wood grain of the concrete surface enhances the sense of scale. The small-scaled textures, together with the imperfections caused by inappropriate construction, became a basic point for people to understand the space and feel the scale. The way we used to compose the space made heavy structure never a problem again. It was not necessary to pursue lightness in the structure itself. Some of the large cantilevers extend outward, some are interrupted or connected by skylights open naturally to the sky. In fact, wooden textured concrete can provide a relatively heavy feeling. If I were only looking for lightness in the material itself, it might be much easier for me to apply smooth concrete surfaces like Ando Tadao. However, I had two considerations for this. Firstly, I wanted the roof to be textured, and its coexistence with the lightness and openness of the space could create an interesting contradiction. Secondly, the construction of the concrete was limited by resources. If we wanted to make smooth and flawless concrete, despite precise control of the formwork, we should also ensure that there would be no colour difference of the material. It required the concrete manufacturer to keep some tanks specifically for this project, which would increase the cost by more than 30 to 40 percent. Our client had no experience in house building. Our construction team specialized in hydraulic engineering construction, and although highly skilled in concrete construction, they were not good at doing a detailed house construction. Considering all the possible situations, we chose to use wood-moulded concrete, which was considered as a more fault-tolerant construction method. We have used this method many times in our previous projects with limited resource so that we were relatively experienced in such type of construction. It doesn’t matter if the concrete surface is uneven or partially patched with wood mold marks. I even asked the workers to stagger the formwork by 1 or 2 centimeters in order to naturally create a strong uneven concrete texture.
The formwork was made of 30cm wide pine boards, which are raw material grade boards in the wood products industry and can be cut into floor boards or slabs we usually use (30cm wide, 4cm thick and 4m long). Such large-scaled boards could create more intense effects on the large concrete structure. We applied carbonization treatment on the boards before they were put into use, which could make the texture more distinct. The same formwork was used for all exposed concrete structure except for the reed-covered portion of the roof, creating a more homogeneous wooden texture. In the early design scheme, the inner surface of the building was also made of concrete. However, a leader of the client was concerned that it would make the house look too cold, so we adjusted the design and covered all non-load-bearing walls with wooden boards recycled from the concrete formwork. The formwork was used once on the front and once on the back, and we recycled most of the formwork, cutting it down the middle to form 18-millimeter thick common panels with one new side and the other one old. The new side was applied in the interior while the old side was used on part of the exterior that was not built of concrete. The wooden formwork was piled up after use and exposed to wind and rain, which caused oxidization on the surface of the material, turning out different hues of gray. We used a normal mix for the concrete and did not control for color differences. To construct the structure, we cast the columns first and then the roofs. Different roofs might be casted by different batches of concrete with different colors. However, since the roofs and columns did not meet horizontally from each other, the color difference did not actually become a problem.
8. There are a large number of joints between glass and concrete in the project. How was the quality of such joints controlled during construction? How to reduce the ecological impact of the construction process?
We used common methods to construct the joints between the concrete roofs and the glass. We didn’t use complicated methods like slotting on the concrete and making water proofing belts. What we did was to install frames on the flat concrete surface and then apply water proofing treatment between the frame and the concrete. The glass façade was equivalent to a single-layer of curtain wall and the size of the glass panels was relatively conventional, which would not cause much problems in construction.
The use of large areas of glass was a contradictory choice. It was beneficial to people as they could see panoramic view through the huge glass façade as if placing themselves in the wetland. However, after the scheme was approved by the client, the staffs working in the conservation area were alerted to the fact that the glass façade was not friendly to birds because they might not realize the glass and bump into it. To solve this problem, we installed a large amount of shading grille on the façade. Except for most of the lower part of the façade, we also added grille to the upper part of the building where people don’t particularly need to see out. We originally wanted to make the grille with the remaining timber formwork, but the reed-covered roofs were already a challenge for us. It was hard to accept using timber grille on the façade because it would not last long in the local environment and had to be maintained and exchanged by professional workers, which would be hard to control. Eventually, we chose aluminum alloy as the material for the grille. Considering all the factors, although the overall effect would not as effective as the timber, it was acceptable because it didn’t need much maintenance. At the end of the last year, we captured a photo of a bird nesting between the grille, which shows that the design of the grille could also benefit the birds, and to some extent establishes a relationship between the architecture and the eco-environment.
If the project was located in an existing wetland, even if artificially restored, we would somehow feel guilty for such large-scale construction, doubting for its necessity: should we build such a huge facility in a paradise of birds? However, what makes this project special is that it is part of a 20-square-kilometer ecosystem restoration project. The construction of the education center was processed simultaneously with the reconstruction of the wetland. We had started to build the house before the site was dredged and the water was never let in until the construction was finished, creating the effect of floating on the water and connecting the building to the wetland. Under this context, the construction of the project would not cause ethical problems because it was a carrier for a particular human-land relationship.
9. What considerations were given to deal with the relationship between the birds and the building?
It is not easy for architects to understand the birds like experts. What we could do was to achieve a certain level of friendly to the birds. The methods should be evaluated and confirmed by the feedback from the environment. A bird watching house is basically designed as a sheltered volume so that people could hide themselves while observing the birds. But our project was not only for bird watching, it was a place for scientific research, exhibition and public education. The project was not competing with the birds for the space. It was merely located in a small corner of the 20-square-kilometer wetland. The only thing we should consider was to prevent birds from colliding on the architecture. But we had made some small mistakes in the design. There are two courtyards in the main building and we found that if a bird accidentally flies into the courtyard, it can not escape by itself. To keep the birds from getting into the courtyards, the administrative staff of the wetland covered the courtyards with meshes. As an architect, I did not anticipate this disadvantage at the beginning. If we had predicted it earlier, we would pay more attention to the design of the courtyard, making it able for birds to escape from. Looking at the project as a whole, we made a relatively soft, vegetated sloping roof that allows the possibility for birds to stay at its bottom. We also compensated the glass façade with bird-friendly grille, minimizing the possible destruction on the living environment for the birds.
10. What is the biggest difference between this project and your previous projects? What challenges did you face in this project?
The environmental qualities of this project was different from our previous projects. Most of our projects are in the city, even if it is located in the countryside, the environment is of strong artificial intervention. These spaces are people-oriented and the houses are built for people. The project in Dongtan seemed located in the first nature, but it is in fact the second nature formed after the strong human intervention. The difference was that people would leave this environment to the birds and never compete with them. At the beginning of the project, I was only vaguely aware of this feature of the environment and our design responded to the following question: how to build a people-oriented building that could also stand in an environment that is not made for people? Mr. Lu Andong have also mentioned this issue in his review for this project. He concluded that although all the design methods applied in this house were people-oriented, the entire design idea and the final result touched the relationship between human and nonhuman beings. When I first visited the site, I was impressed by its enthusiasm and imagination. We used design to face and discuss the relationship between human and nature in such a unique site and responded to this issue in different scales, from the landscape to the building and its surroundings, which was different from our usual projects. We were faced with an uncertain future, but we had to design towards a certain one. It was a challenge that all architects will face with, but the difference was that the site itself in this project was uncertain. The building was going to be constructed in an ambiguous and contradictory environment between man-made and non-man-made, and this specific context posed a great challenge to the design. We grasped the basic feelings and some original psychological perceptions of people during the design, which has also been a strong preference in my personal practice. Usually we do not rely too much on the operation of the form. Architecture in purely artificial environments seems to have strong systematic and rational components, which needs to be controlled by strong physical forms. This project gave us an opportunity to rethink about how to use our design intent to conspire with the future in an environment full of contradictions and uncertainties.
11. What is the most satisfactory part of the project?
We spent 6 years on this small project from design to completion and we had encountered many difficulties during this process. The client was not professional and the construction team had a specificity in their technique. The cost of the construction was also limited. However, the client persisted in the project with us and obtained a relatively satisfactory result. First of all, the space and the environment as a whole have basically achieved the design goal. The building was not a purely void space. There could be things happening in the space and people could participate in. Secondly, the client was more satisfied with the result than us on some level. Although there were a lot of technical aspects of the construction that I wasn’t very happy with, the managers of the site was gratified that the project could be going to the end and reached a relatively desirable result. Having been though a variety of difficulties and unexpected things in the past few years, they had become almost half a professional in such constructions, and their pursuit in this project was one of the key reasons that it could be successfully completed.
12. What is your consideration on the project’s potential for future use? What changes and enhancements might it bring to the neighborhood?
The building is not yet officially put into use. Since the project is located in a protected area, it has limited access. I hope that with the proper functioning of the bird sanctuary, the project can be more widely used, especially on a public education level. Dongtan is a grand ecosystem restoration project and it will bring long-term natural benefits, which should be known by more people. We hope that Dongtan Research and Education Center can become a platform to discuss the restoration of the wetland, helping the public to understand the significance of environmental projection. Environmental protection is not just about maintaining the natural environment, but also about correcting the mistakes of past generations and using resources to restore the natural environment, like what we have done in Dongtan project. It was both a valuable experience in wetland restoration and a great example to be discussed in the context of nature conservation around the world. Only under this background could this project be built and I hope that it can take up the task of exploring this aspect in the future.