Prepared Rehmannia Root Crafts Exhibition Hall / LUO Studio

Architects: LUO studio
Area: 1463 m²
Year: 2021
Photographs: Weiqi Jin
Construction Team: Henan Shancheng Construction Engineering
Design Team: Yujie Luo, Beilei Wang, Yutao Cao, Shangwan Huang, Chen Zhang
Client: People’s Government of Huanfeng Town, Xiuwu County
City: Jiaozuo
Country: China

The Prepared Rehmannia Root Crafts Exhibition Hall, a rural exhibition space in Houyanmen Village, Xiuwu County, designed by LUO Studio, showcases the transformation from production facilities to multifunctional cultural venues. Integrating industrial tourism, education, and wellness, this project completed in 2021, supports rural revitalization and industrial integration in the region. The hall’s design emphasizes the role of natural light in linking traditional craftsmanship with architectural innovation, facilitating a coherent visitor flow and efficient use of resources while respecting the local architectural heritage.

Prepared Rehmannia Root Crafts Exhibition Hall / LUO studio

Xiuwu County, located in the western part of Henan Province within Jiaozuo City and historically known as Huaiqing Prefecture, benefits from unique soil and climate conditions conducive to the cultivation of “Four traditional Chinese medicine herbs,” including Rehmannia, also known as “Di Huang” in Chinese. The term “Shu Di Huang” refers to the prepared or cooked Rehmannia root, which due to its significant medicinal and economic value, along with its related industries, has attracted widespread attention in the county.

The transformation from a “Factory” to an “Exhibition Hall” is exemplified in the Ice Chrysanthemum Plantation project in Houyanmen Village. This shift aligns with the burgeoning medicinal herb industry in the area, bolstered by financial support from the Xiueu County government. Funds from the provincial government have been allocated to various components such as a processing workshop, a drying field, and an exhibition hall showcasing Rehmannia root products (Shu Di Huang). The processing workshop and drying field, both incorporating a portal frame structure, were completed in 2020. Following this, the exhibition hall began its foundation pit excavation in 2020 and concluded construction by 2021. LUO studio undertook the hall’s design in early 2021. The village has focused on rural industrial revitalization, with plantation development playing a crucial role. A common perception across the town and industrial parks is that buildings, including exhibition halls, should maintain a workshop-like appearance. Traditional craftsmen often face challenges in creating large-span, open spaces, prompting many buildings in rural industrial parks to emulate a plant-like form, a testament to their established construction systems. However, the rural industry has evolved beyond its traditional production-centric role to include industrial tourism, nature education, e-commerce livestreaming, health, and wellness. This multifaceted development necessitates the integration of primary, secondary, and tertiary industries for rural revitalization. Consequently, a traditional factory-style building with a portal frame structure is no longer suitable for a multifunctional exhibition hall in a rural setting. LUO studio engaged with stakeholders to shift away from old paradigms and adopt a new approach in the design and construction of the Prepared Rehmannia Root Crafts Exhibition Hall.

“Sunlight” serves as the central element linking craftsmanship and space in the design of the exhibition hall. The design team, through on-site investigations into the processing of Rehmannia roots, identified a crucial element from the traditional Chinese pharmaceutical method described by the ancient physician Sun Simiao, known as the “nine steaming and nine sun-drying” technique. This method, relying heavily on sunlight for drying, fundamentally influences the spatial design of the exhibition hall, which focuses on optimizing light exposure. Light becomes a dynamic player within the structure, shaping the interior and exterior experiences. This concept of utilizing light forms the basis of the design approach. The building’s circular shape enhances the interplay of light and shadows, appearing more nuanced, consistent, and fluid than a square configuration might allow. This circularity, realized through a nearly round architectural form that simplifies to a regular polygon for construction feasibility, maintains the illusion of curves through the use of straight lines. Unlike traditional methods that often involve puncturing the facade with windows to allow daylight, this design opts for innovative daylighting strategies. It introduces light through structural elements like ceilings, eaves, and gaps between walls, creating a unique visual and functional effect.

The exhibition hall features a centrally symmetrical circular plane, ideal for the exhibition space. The design prioritizes visitor circulation within the hall to ensure a logical, straightforward route that minimizes overlaps and unnecessary detours. The layout incorporates a nearly circular plane with a 37-meter diameter, around which the visitor’s path is organized. This configuration facilitates efficient exhibition arrangement and helps in reducing construction costs, which is crucial in rural settings. The structural choice of a 37-meter diameter central column frame within the building’s framework offers an economical approach while allowing dynamic variations in space and scale. These variations lead to the creation of distinct ‘ring’ spaces within the hall. The outer ring combines the enclosure walls with wooden structures, providing an ideal space for display boards. The middle ring functions as a shelving area for showcasing various Rehmannia root products, featuring densely packed structural units of the column frame that ensure stability and optimize storage space. The inner ring, larger than the middle ring, includes a circular and stepped sunken seating area, designed for health and wellness activities. A central skylight at the top of the structure enhances natural daylight and underscores the hall’s central theme.

The sustainable concept in traditional wooden construction, particularly evident in the “furniture as structure” approach, aligns with the “Reduce” principle of the 3Rs—Reduce, Reuse, Recycle. A prime example of this is seen in the clay-shaping rooms of ancient kilns in Jingdezhen, which are still operational. These rooms feature Chuandou timber frames as the structural system. In this system, columns are notched with mortises to accommodate small wooden beams, over which divider panels are placed. These panels support shaped clay during the drying process, reflecting a local construction method emphasizing resource conservation. This conserves materials and space and seamlessly integrates structure, furniture, and space. Drawing on this traditional construction knowledge, the project innovates by transforming traditional large-section columns into arrays of smaller-section columns, arranged both vertically and horizontally. These arrays support secondary small wooden beams, onto which panels are laid to hold items. This configuration serves as both a structural framework and functional shelving, creating a distinctive space. The small column arrays are assembled into standardized modular units, which offer two significant benefits in rural construction contexts: 1) They eliminate the need for large machinery during construction, which is often unfeasible on rural roads with their narrow paths and uneven terrain. The use of smaller components allows for manual handling and community involvement in construction. 2) The modular approach streamlines processing and assembly, substantially reducing labor and material costs. This method proves particularly effective in rural environments where resource efficiency is paramount.

The exhibition hall, based on the regular 18-sided polygon on the plane, strategically repositions one endpoint of each side towards the center of the inscribed circle, aligning it perpendicularly to the extension line of the structural columns. From the exterior, this results in staggered adjoining side walls, creating varied gaps between the walls that permit natural light to penetrate, enhancing the interplay of light and shadow within the space. Internally, the roof truss’s organization of columns and beams generates a distinctive 2.5m-diameter central hole at the dome’s apex, enriching the spatial experience. Addressing the structural challenges of a circular dome, where straightening rods from the arc points to the center could densely populate the central node, complicating connections and escalating costs, the design team innovated a spirally circular overlapping formation for the rods. This method avoids the complexity of shared endpoints and the need for intricate central connecting components, reducing the processing and hoisting expenses. The rods are arranged to support each other in a spiral pattern, distributing pressure efficiently and forming a continuous and complete stress system, which is crucial for the 37m-diameter span of the building to facilitate central daylighting.

Houyanmen Village, with a construction history spanning from the 1970s to the 1990s, predominantly features homes with red-brick masonry walls and triangular wooden frame roofs. The village landscape also includes idle, abandoned structures with gray brick walls and Tailiang-style timber frames, alongside brick-concrete houses erected before 2000. Belonging to Huanfeng Town, a locale with brick kilns operational since the Ming and Qing Dynasties—some still producing red bricks just 2 to 3 kilometers from the village—red bricks have been a cost-effective choice for local construction. In this project, these locally produced red bricks are utilized for both the enclosure walls and internal partition walls. The construction involves local craftsmen who employ traditional masonry techniques, preserving and promoting the area’s building heritage.

In the village, traditional houses usually feature brick walls on the lower levels and wooden frames above. This project mirrors that material scheme, adapting it to the needs of a spacious exhibition area. Here, the wooden frame serves a dual function: it forms the upper roof and acts as the frame-column support for the lower section. To enhance durability and prevent issues such as log cracking and deformation, glulam and wooden poles were selected. These timber rods are securely fastened with bolts and metal connecting components. The integration of local red-brick masonry techniques with an engineered wood frame structure boosts the building’s structural integrity and longevity. It remains sympathetic to the traditional architectural context of the village. This method ensures that the rural industry display building fulfills the spatial requirements while providing high-quality spatial aesthetics that resonate with the local genius loci.