OPEN Architecture's Sun Tower is a soaring concrete edifice facing the Yellow Sea

Beijing-based practice OPEN Architecture is celebrated for its contextual visions and philosophy of creating architecture that transcends the definition of self-contained objects to that of fluid forms that meld into their surroundings. Having previously designed the ethereal Chapel of Sound – a tour de force in acoustic architecture – and the blue whale-inspired Pinghe Bibliotheatre in Shanghai, the studio presents their vision for a watch tower being constructed in the Chinese coastal city of Yantai. The project named 'Sun Tower' is a multi-functional building, chiefly designed as a viewing structure to witness the moment in which the centre of the visible sun is directly above the equator.

Speaking of the guiding principle for the Sun Tower, OPEN Architecture shares, “When we conceived the design, we wanted to reference ancient human rituals, honouring the sun, moon, and stars, and offering a space for reflection and contemplation. We also wanted to ensure the building had an authentic purpose and function, something that would be of benefit to the citizens of Yantai rather than just a folly on the beach.”

The design brief encapsulated the creation of a landmark on the coast which captures stunning views of sunrise across the Yellow Sea. Architects Li Hu and Huang Wenjing took cues from the history of the city, particularly from the fact that during the Ming Dynasty, several watchtowers populated its coast to signal impending attacks. Yantai itself means ‘Beacon Tower’, and from this connotation emerged the idea of creating a tower. “The structure is designed according to careful studies of the sunlight and appears sliced open by beams of light, revealing the interior spaces to the majestic sea,” says the design team.

Sheathed in white concrete, The Sun Tower envelopes a 50 metre-high, two layered shell structure facing the sea. Its robust form, comprising a meticulous linking of concrete shells with horizontal slabs and ramps, is expected to deliver a structural feat, an endeavour undertaken by OPEN Architecture in collaboration with engineering firm Arup. The programmes slotted within the tower includes a semi-outdoor theatre on the ground level, exhibition spaces designed along the winding ramps on the upper floors, and a library on the top-most storey. A 'phenomenon space' designed specifically to witness the equinox is designed as a semi-outdoor space at the tower’s pinnacle. Interestingly, an oculus is designed at the centre of the phenomenon space’s roof, and this opening is created to let rainwater channel through the tower and fall into a pool underneath. While this would be the proposed case for summers, in winters, the pool in its dried state will be used as a fireplace.

The tower sits within a circular gently sloping plaza that features a shallow pool comprising misting devices and spouting fountains. Speaking of other features designed at the base of the building, OPEN Architecture shares, “A specially designed water channel cuts across the plaza - a ruler of time - this is the straight line that the shadow of the Sun Tower will follow on the day of the Equinox. A series of elliptical rings are set in the pavement pattern; the intersections between the rings and the water channel mark the building shadow’s footprint at specific hours on the equinox day. At one of the outer rings, a series of fountains were designed to celebrate the 24 Solar Terms of the Traditional Chinese Calendar; on normal days they are synced with high and low tides.”

The exhibition spaces within the tower are conceptualised with the intent to create a digital museum focused on bringing digital exhibitions and big data technologies. Working together with French firm Ducks sceno, the project involved architect Aric Chen, General and Artistic Director  of Het Nieuwe Instituut (HNI), who STIR recently spoke with in an exclusive conversation. Chen, with his prolific curatorial expertise in the paradigm of cultural institutional practices and contemporary design, consulted on the project to decide a way on how digital could be tied up with phenomenology within the tower.

“From educational institutions to cultural projects across China,” Chen describes OPEN Architecture’s role in realising such projects: “they have shown time and again how architectural innovation and social innovation go hand in hand.” “OPEN has a remarkable ability,” he continues, “to take on an architectural assignment and infuse it with meaning and purpose; in their hands forms follow content.”

While the Sun Tower is under construction, it is expected to be unveiled to the public in 2024. The project will appear in OPEN Architecture's forthcoming book titled Reinventing Cultural Architecture: A Radical Vision by OPEN, scheduled to come out in April 2022.

The Sun Tower appeared in a recent article authored by our columnist - architecture and design critic John Jervis - who delves into the vocabulary of ‘experiential architecture’ and how particular structures work as destinations.