jan 15  |  American-Architects

Building of the Week: FKI Tower

by John Hill 

Resembling a simple glass-box office building from a distance, up close the 50-story FKI Tower reveals a simple yet ingenious wall section that incorporates solar panels angled to absorb more of the sun's rays than a strictly vertical surface. Further, a number of atriums and a rooftop garden serve the office workers in the tower, and a podium that provides amenities for public use. World-Architects first learned about the FKI Tower during a studio visit to Adrian Smith + Gordon Gill Architecture's Chicago office in 2014, and here AS+GG answers a few questions about the project.

What were the circumstances of receiving the commission for this project?
AS+GG won an international competition to design the tower in April 2009.

Please provide an overview of the project.
The 50-story, 240-meter tower features an innovative exterior wall, designed specifically for FKI. The building’s unique skin helps reduce internal heating and cooling loads and collects energy through photovoltaic panels that are integrated into the spandrel areas of the southwest and southeast facades.

What are the main ideas and inspirations influencing the design of the building?
The concept for FKI was developed by combining the client’s request for a building that was contextual to the predominantly orthogonal architecture of the Yeoido District and the city’s requirement that all new large-scale commercial buildings generate a minimum of 5% of their energy onsite. The design team developed a strategy that would meet both requirements as well as reduce the amount of energy that the building used for its heating and cooling loads. The use of building integrated photovoltaic panels (BIPV) was seen as an architecturally appealing way to meet the strict zoning requirement, while the optimization of the panels became a driving factor in developing the architectural expression.

Another deciding design factor happened early in the process when the design team learned that the local electric utility company (KEPCO) would provide a favorable 5 to 1 buy-back rate for onsite green-energy generation. The payback for the BIPV panels, which would have typically been 30-35 years, was reduced to about 7 years due to these incentives. As part of the initial design process, an Ecotech® model was used to determine the optimal areas for BIPV on an orthogonal building, given the surrounding buildings which partially shade the site. It was determined that BIPV would be best used on the southeast and southwest faces above Level 14. The detailing of the spandrel panels are interchangeable with PV, which allows the design to be flexible for future changes.

Were there any significant challenges that arose during the project? If so, how did you respond to them?
Not all sides of the building are currently suitable for BIPV, therefore it was important to design the panels that were interchangeable with insulated spandrel panels for maximum flexibility without a significant change in the symmetry of building expression. The design also allows for the panels to be replaced as new technology that can take advantage of indirect light becomes available.
Also, the site organization was rearranged from the original competition brief by sliding the tower to the west. This opened up more site frontage and allowed the podium to be closer to the street. This positioning gave the podium a presence and identity unavailable if it was located behind the tower.

How does the building relate to contemporary architectural trends, be it sustainability, technology, etc.?
FKI’s unique exterior wall system combines maximum access to views, energy efficiency strategies and energy generation technologies. By angling the spandrel panels 30 degrees toward the sun, the amount of energy collected by the photovoltaic panels is maximized. Below the spandrel panels, the vision panels are angled 15 degrees toward the ground, minimizing the amount of direct sun radiation and glare.

The result is a unique folded exterior texture that is both purposeful and visually distinctive. Benefits include a reduction of glare and heat gains from direct sunlight, while maintaining a high level of indirect light. With the exception of the early morning and the late afternoon periods, the building is able to use the geometry of the exterior wall to self-shade the perimeter spaces that would normally be inundated with direct sunlight. This gives the building occupants the flexibility to open the shades and allow indirect natural light. With a maximum lease span of 12 meters the majority of the building occupants benefit from the increase natural light.

FKI clearly illustrates an advancement in building facades from simple wall systems to high-performance, integrated architectural and engineering design solutions. The design team worked to create an intelligent, high-performing, forward-looking building that exhibited timeless and enduring qualities. FKI’s grand opening was celebrated in Seoul on December 16, 2013.

How did you approach designing for Seoul, Korea, and how would you describe the process of working on the project there?
Federation of Korea Industries (FKI) invited three international architectural firms to a three-month design competition in 2009.

AS+GG established the following Design Concepts:
1. An Icon of the city of Seoul
2. A world-class business center
3. High performance exterior wall system

How would you describe the architecture of Seoul, Korea, and how does the building relate to it?
In the last twenty years, Seoul has evolved at an astounding pace by building modern and energy efficient buildings. Seoul’s mission has been to project a world-class global image, while creating its new look.
Currently many buildings have redefined traditions and pushed the pace of innovation through ultra-modern design. Several supertall buildings are under construction or planned to be built in populated regions in metropolitan areas of Seoul and Busan.

FKI Tower is a major new addition to the skyline of Seoul. The 50-story, 245-meter-tall tower is the first in Korea to use a pressurized underfloor air distribution system, includes integrated photovoltaic panels on its façade, and is Korea’s first commercial building to receive the highest score for sustainable design, Grade 1 in Environment Friendly Building Rating.

The exterior wall also help to create a dynamically "rippled" façade, giving the tower a visually striking architectural presence on the skyline of Seoul.