Architects: SAKO Architects
Area: 2,137 m²
Year: 2024
Photography: Misae Hiromatsu
Principal Architect: Keiichiro Sako
Architectural Design, Interior Design & Landscape Design: SAKO Architects
Client: Ascot Corp.
City: Fukuoka
Country: Japan

VECTORS in Fukuoka, an office building designed by SAKO Architects in Fukuoka, Japan, redefines mid-scale workplace architecture in a rapidly redeveloping regional city. Completed in 2024, the ten-story project integrates architectural, interior, lighting, and landscape design to enhance energy efficiency and urban interaction. Its distinct façade consists of 120 modular steel louvers made from 9mm-thick plates, whose varying depths respond to solar angles, nearby structures, and key views, reducing HVAC energy use by 4.3 percent. By day, these louvers produce sharp, shifting shadows, while at night, embedded LED uplights transform the grid into a floating checkerboard of light. Steel, chosen over aluminum for its greater stiffness, durability, and lower thermal expansion, was treated with hot-dip galvanization and phosphate coating to achieve a deep matte texture. The project introduces a landscaped pocket park at street level and rooftop terraces with panoramic views of Hakata Bay. It has received a DBJ Green Building 4-star rating for its energy performance, disaster resilience, and community-oriented contributions.

The VECTORS in Fukuoka office building by SAKO Architects explores how mid-scale workplaces can respond to dense urban environments while adding value to their surroundings. Designed by Keiichiro Sako, the project is described by the architects as a “convergence of directional forces,” combining material precision, environmental logic, and spatial experience. This approach positions the building as both an efficient workplace and a meaningful urban contributor in Fukuoka’s evolving cityscape.

How would you describe your design philosophy?

In one word, it is “theme.” In all my projects, I establish a clear design theme and ensure consistency from the overall concept down to the smallest details to reinforce that theme. The theme serves several crucial roles.
Interview with Keiichiro Sako (迫慶一郎) of SAKO Architects

The façade is the building’s most distinctive element. It consists of 120 steel louvers with depths that change across the grid to optimize shading, manage views, and connect with surrounding buildings. These calibrations, guided by solar studies, reduce the building’s cooling energy demand by 4.3 percent. During the day, the razor-thin steel edges create intricate shadows, while at night, integrated LED uplighting transforms the grid into a glowing matrix, giving the building a lighter, almost floating presence.

The material strategy prioritizes performance and durability. Steel was chosen instead of aluminum for its threefold stiffness, reduced thermal expansion, and ability to form thinner louvers without compromising strength. Hot-dip galvanization and phosphate treatment provide a matte, textured finish and improve weather resistance. Precision fabrication, achieved through Japan’s nationwide steel network, allowed for cost-effective yet highly detailed execution.

Public interaction and urban integration are central to the design. A landscaped pocket park at street level enhances the pedestrian network, while rooftop terraces, including a counter facing Hakata Bay, offer shared and private outdoor spaces for occupants. The building’s clean, rectilinear massing maximizes usable space and avoids setbacks, reinforcing its strong presence within the Tenjin district.

Construction relied on direct anchoring of the louvers to the structural frame and advanced laser scanning to minimize errors and reduce on-site adjustments. This precision helped the project earn a DBJ Green Building 4-star certification, recognizing its energy efficiency, disaster preparedness, and contributions to the local community.

The name VECTORS reflects the design’s conceptual foundation, symbolizing the interplay of light, shadow, context, and human movement. Through this multifaceted approach, the project offers a refined model for how compact office buildings can meet environmental, structural, and cultural needs in rapidly changing cities.