Quadrature of the circle
The Prepared Rehmannia Root Crafts Exhibition Hall celebrates an important medicinal herb used in Traditional Chinese Medicine. Luo Studio has created a shrewd design for a dome based on cost-efficient construction using standardized structural timber.
The production of medicinal plants for Traditional Chinese Medicine has a long history in Xiuwu County, Henan Province. It is an important part of the economy in this area of China, where the soil properties and climatic conditions offer ideal advantages. One of the most significant herbs in the regional medicinal plant industry is the Rehmannia root, also called the Chinese foxglove. The complicated, traditional process required to produce this medication can be traced back to the sixth century, to the famous physician and religious studies scholar Sun Simiao.
Light becomes the central theme of the building, generating dynamic changes both inside and outside.
Luo Studio, architects
As part of an initiative for rural industrial revitalization, the provincial government provided the necessary funds to preserve this cultural heritage and make it accessible to the public. The processing workshop and drying field were completed in 2020, and renowned Beijing architects Luo Studio were subsequently commissioned with designing the exhibition hall. Named the Prepared Rehmannia Root Crafts Exhibition Hall, it was completed in 2021 and received the Architizer A+ Award in the category Cultural and Expo Centers in 2024.
New paradigm for construction and design
In a departure from conventional, purpose-built production halls, the architects made a case for a new approach to both design and construction method. Besides the wide-span hall specified in the commission brief, the design includes references to regional building culture and fulfils a number of ecological requirements.
However, the pharmaceutical production process for this medicinal root plant was the underlying factor behind the building’s striking appearance. In between several cooking stages, drying in the sun is crucial here. “Light becomes the central theme of the building, generating dynamic changes both inside and outside. This is the fundamental starting point for the design,” explains Luo Studio in a description of the design process.
Straight lines form a circle
The interplay of natural light and shadows changes continuously as the sun moves across the sky. Luo Studio argued that this is shown to best advantage in a round building compared to one with corners. Therefore, the design team decided on a near circular shape with a regular, polygonal ground plan. The construction is consequently without any curved structures that would have incurred extra costs. Instead, the curved effect is created by the straight lines of the staggered brick walls that are so typical of the local area.
Daylight streams into the building in an unconventional way, as the architects explain: “Deviating from the common approach of carving out window holes in the building walls, natural light is introduced through ceilings, eaves, and gaps in between walls, for example.”
This practice not only saves materials and space, but also integrates structure, furniture and space into a whole.
Luo Studio, architects
Resting on top of the red brick masonry walls, a timber dome rises up with an impressive diameter of 37 metres. The construction method is based on simple glulam beams and squared timber screwed together into modular units. This avoided transportation of large structural components over long distances and also reduced the use of materials.
Structure = furniture
At the centre, a round space – entirely free of supports – is embedded in the roughly circular exterior shell. This recessed seating area has several steps leading downwards underneath the skylight, creating a special atmosphere and “sense of centrality”. Appropriately, health and wellness offerings are most frequently encountered here.
In contrast, the outer ring is reserved for exhibition space and divided into regularly-spaced segments by the wooden frame. Adopting a principle that originated in traditional ceramic furnaces in the imperial porcelain city of Jingdezhen, the wooden construction also serves as furniture. Shelves between the timber supports are used to store pottery even today.
Moving around central stillness
In the Prepared Rehmannia Root Crafts Exhibition Hall, the frame structure also functions as exhibition space. “This practice reflects local construction wisdom, resonating with the ethos of cherishing resources. It not only saves materials and space, but also integrates structure, furniture and space into a whole,” Luo Studio explains.
Besides the cost efficiency of their solution, this creates natural zoning in the hall. While visitors walk around the outer ring, the steps in the inner ring create an island of tranquillity.
Text: Gertraud Gerst
Translation: Rosemary Bridger-Lippe
Photos: Weiqi Jin