Swirling Cloud: Bulletin Pavilion For BJFU Garden Festival / SUP Atelier

Architects: THAD SUP Atelier
Area: 120 m²
Year: 2018
Photographs: Su Chen, Chun Fang
Bamboo Contractor: Anji Zhujing Bamboo Technology Co.Ltd
Lighting Design: X Studio, Tsinghua University, School of Architecture
Design Team: Yehao Song, Xiaojuan Chen, Jingfen Sun, Dan Xie, Mengjia Liu, Yingnan Chu, Haowei Yu, Shaohang Shi
Clients: Beijing Forestry University
City: Haidian
Country: China

The Swirling Cloud Pavilion, designed by SUP Atelier for the 2018 Bamboo Garden Festival at Beijing Forestry University (BJFU), is a bamboo structure serving as an information hub during the event and later as a flexible gathering space. Located at the center of a spiral square surrounded by groves, shrubs, benches, and stone carvings, the pavilion’s design leverages bamboo’s flexibility, strength, and modern processing technologies. Inspired by a Chinese verse about sweeping clouds, the structure features dynamic curves and openings aligned with surrounding elements, creating a light-filled space with a central skylight. Digital modeling guided the design and prefabrication of bamboo elements, ensuring precision while integrating modern and traditional construction methods. Bamboo beams were assembled using mortise and tenon joints, reinforced with concrete foundations and waterproofed using bamboo tiles and PMMA. The pavilion’s adaptable design showcases bamboo’s potential for contemporary architecture and proposes a prototype for sustainable, site-responsive structures.

Swirling Cloud: Bulletin Pavilion for BJFU Garden Festival / SUP Atelier

Situated within a grove on the campus of BJFU, the “pavilion of clouds” is a bamboo structure created for the 2018 “Bamboo Garden Festival,” commissioned by the university’s faculty. Spanning an area of approximately 120 square meters, the pavilion functions as an information hub during the festival and is intended to serve as a versatile space for recreation and gatherings once the event concludes. The site, bordered by campus roads to the north and west, is a spiral-shaped square surrounded by groves, bushes, memorial stone carvings, and benches, with the pavilion positioned at its center.

Adaptability & Strength: Exploring Bamboo’s Potential
The design process capitalized on the flexibility of bamboo, as the site’s conditions imposed few limitations, enabling the team to focus on bamboo’s structural and material characteristics.

Bamboo stands out as one of the most versatile structural materials, offering features that surpass those of wood. It exhibits exceptional bending and tensile resistance, making raw bamboo easy to bend and shape. Modern bamboo processing technologies allow precise sizing and shaping, either in factories or directly on-site. Moreover, once dried and shaped, processed bamboo resists outdoor deformation, enhancing its durability and reliability for construction.

The advantageous site conditions, combined with the unique properties of bamboo, enabled the creation of a free-flowing, relaxed form that also conveys a sense of strength. This design harmonized with both the campus’s aesthetic and the garden festival’s atmosphere.

Clouds in the Gale: Reversing the Design Process for Building Elements
The pavilion’s form draws inspiration from a famous line in an ancient Chinese poem: “A gale has risen and is sweeping the clouds across the sky.” The design team sought to evoke the imagery of rising winds and drifting clouds through the pavilion’s flowing structure. Combining traditional raw bamboo construction techniques with modern building technologies, they began with a conceptual design. The overall structure was then developed using digital simulations, with the resulting digital documents serving as precise guides for on-site construction.

Compared to traditional methods involving small physical models, the digital approach offered several advantages. Digitalization was integrated throughout the design and construction process, enabling bamboo components to be prefabricated in factories under controlled conditions for shaping and bending before on-site assembly. This ensured precise execution of the conceptual design. Furthermore, digital technology allowed the curved envelope and key bamboo beam forms to be optimized, aligning them more effectively with structural stress requirements and construction standards.

The pavilion’s design incorporates several openings at varying heights, aligned with the surrounding roads, trees, bushes, and memorial stones. These openings allow visitors to pass through the pavilion from multiple directions. Existing bushes were preserved and extended into the interior space, while the pavilion’s upper section tapers into a round skylight. This design brings sunlight, wind, and vegetation into the space, creating an open, airy atmosphere that evokes the image of swirling clouds.

During the design process, digital models were combined with the conceptual design to refine the pavilion’s structure. Following consultations with structural engineers and bamboo contractors regarding construction methods and procedures, the digital model for key building components was developed step by step. Initially, the positions and shapes of the pavilion’s fundamental curves, including its multi-directional openings and skylight, were established to create the curved roof and central cone.

Based on beam spacing estimated from prior experience, all curved beams were generated and overlaid with a crossing grid of bamboo splits, integrating the roof’s structural components into a cohesive whole. To address requirements for daylight and rainproofing, bamboo tiles and PMMA were chosen as roofing materials, both suitable for application on curved structures. Once these elements were finalized, the positioning of the curves was completed.

Mortise & Tenon Connections: Structural Analysis & Detailed Design
Raw bamboo has been widely used in building and bridge construction, particularly in South China, where bamboo is abundant. Although precise structural calculations were not performed prior to construction, the bamboo contractor and structural engineers relied on empirical estimations to meet construction requirements. The pavilion’s shape, size, structural form, and design details were collaboratively determined through their expertise and coordination.

Bamboo beams, with parameters defined through digital simulation, were prefabricated and numbered in the factory before being assembled on-site. These beams were anchored to the ground using metal fittings and a strip foundation made of cast-in-place concrete. Connections between beams oriented in different directions utilized traditional bamboo construction techniques.

To address the requirements for natural light, rainproofing, and an intimate atmosphere created by the partially curved roof, bamboo tiles and PMMA were chosen as roofing materials, supported by a waterproof membrane and reed mats beneath. The pavilion’s central cone served dual purposes as a structural support and as a conduit for both daylight and artificial light. Permeable gravel paving and pebble-filled seepage pits were implemented around the site to prevent water pooling at the joints where bamboo beams meet the ground.

During the design process, which integrated raw bamboo building techniques with modern technologies, a degree of error tolerance was accommodated, unlike the precise requirements of prefabricated wood or steel structures. Bamboo splits and tiles allowed for on-site adjustments, enabling minor errors to be corrected through the flexible processing of raw bamboo. This approach also preserved the handcrafted qualities of the pavilion.

The construction logic of the project aimed to achieve more than just creating a “pavilion of clouds.” It sought to develop a practical prototype that aligns with contemporary needs and can be adapted for various sites, leveraging the exceptional flexibility of bamboo design.