Jiangsu Garden Expo Treasure Pavilion crystallises converging tectonic tensions

While it is relatively common to see natural phenomena serving as a source of inspiration for an architectural parti, the Jiangsu Garden Expo Treasure Pavilion in Nanjing, China, is a unique case. Effectively functioning as a space to display traditional handicrafts and folk art, the origins of the project's morphology channels the very mechanics of geotectonics as the foundation for an exercise in architectural tectonics. Situated near the Tangshan Fangshan GeoPark in the far north of Jiangsu Garden Expo Park, the 15,500 sqm project by Chinese architecture practice AZL Architects applies the concept of tectonic "folding" - where rocks are bent by stress induced through compressive forces along convergent plate boundaries - to shape a corten steel-clad structure that, "itself becomes a piece of rock fragment on the land.”

The sense of conflict between convergent plates that gives rise to the folds of mountains is also somewhat embodied by the incongruity in the urban character of the project’s context. Along its southern edge, the bustle and motion of a high speed train line between Beijing and Shanghai, is contrasted by the serene expanse of a small-scale village style hotel apartment complex to the north in the form of the VOCO Nanjing Garden Expo. As the design team at AZL Architects notes in a statement: "The city and the village collide on this marginal plot.”

Previously, the neighbouring region was also once home to the Chinese Cement Factory, which was decommissioned and relocated, making room for the Garden Expo Park, which forms a more sustainable addition to Nanjing’s urban landscape. Flat, low-lying terrain now defines the centre of the Garden Expo Park - the product of mining and cement production. AZL Architects' intervention occupies a slim green belt between the mountains and the railway line, on the park’s northern edge, on a plot that extends 190 metres in length and 75 metres in width. Spurred on by the prevalent tension between forces stemming from the site’s past and present, the complex has been articulated in an imposing rectangular envelope, which morphs into a series of winding rust-coloured walls that, "all become natural strokes on the canvas of the earth.”

Here, the notion of folding emphasises heaviness, embedding the structure into the ground and merging it with the terrain - such that the "folded" partitions appear to ebb and flow in accordance with the existing geological strata. “This idea creates a rich roof/ground form while the building itself is divided by several free broken lines from east to west into three parts with different heights, nested into each other," mention the architects. On its eastern and western ends, the structure's corners have been slightly raised, creating different impressions of form and scale when viewed from afar.

As the design team relays, “The connection between the building and the site is reflected in two ways of 'being seen'. While viewing the building from the Beijing and Shanghai high-speed railway, people can see winding rust-red folded walls, changing light and shadows, and linear arrangements of green plants." They add, "To the south side of the Treasure Pavilion, the layout of the VOCO Nanjing Garden Expo Hotel complex features small scale structures and pitched roofs, in the style of a village community. While looking towards the Treasure Pavilion from the streets of the hotel, a narrow and long red mountain-like background shows up."

Limited fenestrations along the structure’s outer walls create an almost continuous stretch of red surfaces, which are lifted up at two corners to resemble the undulations of mountains in the backdrop. This grand façade design radiates an almost brutalist charm, which is moderated by the weathered corten steel envelope, referencing the reddish brown colour of the rocks that were once quarried here. As per the architects, the effect here is reminiscent of the tension seen in the rust steel sculptures of American artist Richard Serra, which is continued by the winding paths along the structure’s fifth façade - the roof.

Huatian Road, on the eastern side leads to the main entrance, where visitors can enter the structure past a plaza and an L-shaped parapet that splits the route of entry into a ramp and a staircase, linked to the building entrance and an exhibition hall on the ground floor respectively. A sense of ritualistic intrigue pervades this journey, beginning with a doorway that precedes the plaza, followed by a series of spatial transitions before emerging into the main exhibition hall. Expanding and contracting dramatically, the spatial extent ranges from small enclosed zones to vast volumes that rise to nearly the entire height of the building. Those who enter the front yard will also run into visitors returning from the roof garden, which provides the first visual indication of the continuous three-dimensional circulation path that runs through the building. All notions of floor separation and discrete levels have gone out the window, as the terraces and inclines organically interlink to replicate the progression of natural topography.

AZL Architects states, “While the L-shaped parapet projects tension on the plaza just in front of the building, the action of ‘entering’ has already been included as one part of the spatial flow.” The inner surfaces of the corten steel walls enclosing the courtyard have been fitted with metal lattices, as support structures for ivy climbers below to ascend and form a green curtain in the future. The designers reflect, “In the past, people were mining here and left those mine outages which became the scars on the earth. In the future, these green ivies will cover every inch of the grilles on the corten steel panels, and the Treasure Pavilion will eventually disappear into nature.”

A section of the original rock strata from the Jiangsu Garden Expo Park - has been incorporated into the design, in the form of stone fragments excavated from the mountains, that are contained within cage walls at one of the building's entrances. The dull red colour of the rocks on display radiates an ancient regality, devoid of exuberance, yet exuding power. An evident departure from the yellow and blue strata seen elsewhere throughout the park, this showcase of geological heritage records impressions left by time and exists in harmony with the materiality of the corten steel.

While the main extent of the exhibition hall is located on the ground floor - which accommodates an open sunken courtyard and landscaped steps - the circulation paths through the building adopt two trajectories that unite into one. The inner pathway circles through the exhibitions, as the outer one permits sightseeing on the roof garden. Together, they form a continuous Möbius loop," explains the design team. Along this path, visitors can naturally explore the space, guided by views of the nearby landscape, experiencing its every facet from varying points of view. Overlapping produced by this circulation configuration softens the sheer heaviness of the rectilinear block - which is only concave at its northeast and southwest corners - establishing different perspective relationships when seen from vantage points throughout the surrounding context.

Boasting dynamic landscape architecture that comprises green terraces, plazas, and zig-zagging paths in a complex spatial flow that defies the constraints imposed by conventional tectonic paradigms, the project delves into questions of how natural changes could possibly act as precedents for architectural form giving, through the idea of "folding". AZL Architects concludes: “Geological folding builds terrain. Spatial folding creates sequences. Temporal folding returns to a primitive state. Folding, as applied in the Jiangsu Garden Expo Treasure Pavilion, has significance across multiple levels. Folding repairs the past and connects it to the future by applying time-changing materials. Folding is a paintbrush, building up curved walls to depict the site, creating a piece of land art. Folding is also an operational method, which amplifies the experience of visiting the exhibition, removing limitations imposed by the concept of a floor to form continuous spatial sequences.”

Project Details

Name: Jiangsu Garden Expo Treasure Pavilion
Location: Jiangsu Garden Expo Park, Nanjing, Jiangsu, China
Year of Completion: 2021
Site Area: 15000 sqm
Floor Area: 15500 sqm
Client: Jiangsu Garden Expo Construction development Co., LTD
Architect: AZL Architects
Principal Architect: Zhang Lei, Qi Wei, Li Chenxing
Design Team: Li Chenxing, Wang Liang, Zhang Cheng (Architecture)
Interior Design Team: Ma Haiyi, Cao Yi, Huang Rong, Chen Yingjie, Peng Mingxing, Pu Sirui, Luo Tiantian
Landscape Design Team: Zhao Min, Jiang Zhiyuan, Lian Hao
Construction Drawing Team: Nanjing Yangtze River Urban Architectural Design Co., Ltd.