This proposal is an attempt to unify the old Seoul City Hall and the new Seoul City Hall to create "one" space that is also at the same time of "many," as an opportunity to create an architectural and urban embodiment of unity and multiplicity that is required by contemporary democracy in a most tangible way.

To achieve Unity and Multiplicity simultaneously through architecture, the new Seoul City Hall should establish a single identity as a complex, while sensitively maintaining respect to the iconic old City Hall structure and drawing from the diverse urban context the site's full potential. Hence, the new proposal should be formed by the complex conditions that have existed within and beyond the site.

The new Seoul City Hall that is the spatial result of combining potentials will not only synthesize the past and the present, but define what is "public" in a completely new way. The purpose of this proposal is for the new City Hall to create a continuity with Seoul's six hundred year old history while co-existing harmoniously with the larger future of the 21st century and beyond; to help create an identity that the diverse 10 million-plus citizens of Seoul can share.

 

Unity and Multiplicity 1: Spatial Layout Strategy
The old City Hall building, which was built in the early 20th century, should not be preserved passively as a historic relic. Instead, it must function as the active genetic origin of the new building to create a unified identity through expansion.

Perimeter Block Typology
How do you start a perimeter block, from the existing City Hall's old European urban typology (via Japan), and adapt it seamlessly into 21st century Seoul's urban condition?

This proposal is an attempt to reinvent the old perimeter block typology of the existing City Hall specifically to the site's unique conditions. This new typology will evolve from the restrictive Old European perimeter block layout to fit Seoul's urbanity, with an expansive ability to accommodate a variety of openness, accessibility, density and height.

The Ensemble of a New Perimeter Block Typology
The entire complex will create the effect of an ensemble, rather than an accidental collection of architectural objects from disparate eras. To form this ensemble, we will take the old City Hall's perimeter block typology as a framework to reconstruct the relationship between the site's existing internal and external conditions to situate the new building. First, the old four-story City Hall building, which will be used as a public library, will be on one side of the courtyard, while various facilities of public nature (e.g., the Symphony Hall, Dasan Plaza, and public support services) will be on the same level on the other side, in the perimeter block's podium. With the four story podium as the boundary, offices, conference rooms, and other facilities will be located as appropriate in masses atop the podium.

City Hall 'Madang' (Courtyard)
'City Hall Madang' (courtyard) at the center of the complex can connect and unite all of the diverse programs along the perimeter of varying heights. Since Madang can be approached from all directions within the site and is accessible to all as a public urban lobby, it is the most public of spaces inside the complex. This Madang will not only be an iconic open space defined by the old and new City Hall, but also function as a unique urban catalyst for social activities of Seoulites. Madang will be linked powerfully to an iconic public space, Seoul Plaza to the south, and present another iconic three-dimensional space that contrasts with the Seoul Plaza's flatness.

In the center of the octagonal Madang, there is a void surrounded by glass to let natural light into the basement, with an octagonal pavilion at its center. The pavilion functions as subterranean landmark in two levels of massive basement space that contains public programs. The roof of octagonal pavilion is exposed like the tip of an iceberg, with the Madang sloped toward its center as the focus of an amphitheater-like space. The podium and masses containing diverse programs that envelope Madang with unique, continuously folded three-dimensional planes that help make Madang one enormous bowl-like space. This strengthens Madang's centripetal force, and it functions diversely as a social catalyst and new public space.

If the courtyard of the old perimeter block typology is a flat, introverted one closed in by the opaque external façade, the City Hall Madang is simultaneously open, three-dimensional and a dynamic new space that acts as the heart of a city.

Symphony Hall
The Symphony Hall, the most public of the programs, will be located on the four story podium on the northwestern side facing Sejongro in the new City Hall extension. The Hall will contribute a new element that corresponds to the larger context of Sejongro with its significant public spaces, such as Gyeongbok Palace, Duksoo Palace, and the Sejong Cultural Center. The Hall's foyer will be located on the site's prominent northwestern corner and act as another entrance to Seoul City Hall.

Office Towers
Offices, the largest program element, will be contained in two connected towers of different heights on the northeast corner of the site. By placing the towers as far as possible within the site from the existing City Hall, this layout avoids overshadowing the old building's iconic stature. Its two-tower composition functions as one, yet is articulated into two towers 82.4m (18 storeys) and 107.3m high (24 storeys)—another way to prevent overpowering the old City Hall with one large vertical mass while maintaining harmony with surrounding office towers of similar scale. Moreover, this layout creates a functional and spatial urban continuity by internalizing the characteristics of surrounding high-rise buildings located along the northern and eastern streets appropriately. As a result, another iconic new entrance will be created in the space between the two towers on the northeastern corner, in addition to the southern entrance to the old City Hall and the northwestern Sejongro entrance to the Symphony Hall. The northern office tower's podium will be extended to the northwestern Symphony Hall's podium, while the eastern office tower's podium will be extended to the public facilities on levels two to four on the southeastern corner's podium mass, forming a larger perimeter block podium in the public realm.

Conference Rooms and Other Facilities
The conference facilities start on the podium's fourth floor with a press conference room, reporters' lounge and continue on to the seventh floor with conference rooms in various sizes. Facilities for employees begin on the fifth floor clubroom/lounge area, connected with the roof garden on the eastern end. The dining room and fitness center will each have terraces, located on the eight and ninth floors, and will be connected to the roof garden on the tenth floor reserved for employees.

Basement Levels
Two major public programs will be located on the basement levels, directly accessible from various points on the ground floor, via escalators and stairs from sunken areas on the site's southern, western and northeastern sides. In addition, there is a visitors' elevator and a sunken garden with an external staircase to access the public spaces on the basement levels as well as the podium's five levels on the southwestern side of the Madang. Two additional staircases will be installed to reach the sunken area of the subterranean octagonal pavilion in the center of the Madang, mitigating the limited lighting conditions and openness of the basement in a variety ways.

On the first basement level, three access paths will gather at the octagonal pavilion in the center below the Madang. The Information Center, housed in the pavilion, will be surrounded by such facilities as a foreigners' help desk, Seoul Information Center, tourist information center, travelers' lounge, souvenir stand, and public restrooms. A post office, bank, bookstore and other shops will be located along the western side. The sunken areas on the southern and western sides will be connected via underpasses from outside the site, heightening accessibility.

On basement level two, the central pavilion and the surrounding space will form the skylight of a cutting-edge IT showroom and digital information space. A consulting and support office for small and mid-size business owners will be located on the northeastern and southeastern ends of this space. The remaining southern end of basement level two will contain a variety of conveniences.

On basement level three, there will be parking for 120 vehicles and a convenience store in the southern sunken area.

Sky Lounge
There is a sky lounge planned for the top (24th) floor of the northern tower for public enjoyment, accessible by a dedicated elevator from basement level one. The lounge will be connected to the roof garden, with sweeping views of downtown Seoul from inside and outside the building.

Other Outdoor Spaces
With the City Hall Madang at the center, connecting outdoor spaces with interior spaces on various levels vertically expands the public nature of the courtyard's outdoor space.

On the first floor, there are gardens with pine trees planned for the southeastern, northwestern corners in addition to the Madang. Furthermore, two entry gardens located inside the vertical louvers on the southern and western sides will be planted with pines. The southern entry garden will be extended into another small courtyard surrounded by the rear of the old City Hall, with water elements and trees, such as maples, providing a calm, restful space.

There are outdoor spaces surrounding Madang on levels two, three and four that connect the Symphony Hall, library (old building), Dasan Plaza, the press center, etc., from the outside and also function as rest areas.

The rooftop garden on the fifth floor is connected to the roof of the old City Hall, forming a double loop that circulates around the Madang. It is connected to the variety of public programs in the podium and can be approached from different points, thereby functioning as rest areas as well as a public outdoor space. A lounge and a bar on the fifth floor interior increase its effective use.

The southern incline of the northwestern mass will provide large terraces on levels six to nine on the southern side. The terraces can be utilized as independent outdoor spaces for conference rooms, the employee dining room, and the fitness center. The largest rooftop space will be on the tenth floor of this building, reserved for City Hall employees.

From the sixth floor, terraces of varying sizes on different levels in between the two towers improve the work environment. There is also a private garden for employees that comprise a part of the eastern tower's roof, while a public rooftop garden is slated for the 25th floor of the northern tower, connecting to the Sky Lounge one level below.

 

Unity and Multiplicity 2: Building Envelope
In order to create a unified identity, the old City Hall building provides not only the genetic origin of the new extension's spatial layout, but also of its external façade.

Classic vs. Contemporary
How can a classical, European-style building from early 20th century and an early 21st century building create stylistic harmony and manifest themselves as one, unified result?

Louvers
The main materials of the new City Hall's façade are the same granite stone used in the old structure, matte acid-etched aluminum and glass. Granite will also be used to finish the majority of the exterior and interior floors.

This is the most effective method to reduce discordance with the old structure's stone façade and create physical and textural unity. However, as a departure from the heavy, impenetrable feeling that the classical use of stone imparts, this emphasizes lightness and openness. Therefore, the façade of the new City Hall will be comprised of louvers made of matte finished granite and acid-etched aluminum sheets of similar texture and color to granite. There are both vertical and horizontal louvers on the building. Variation in depth and placement according to function and environment define the entire envelope of building. The ambiguous visual characteristic of the stone louvers create an open or closed effect, depending on the viewer's location. The dramatic change from daylight to nighttime will also impart manifold impressions to approaching Seoulites.

Perimeter Walls: Vertical Elements
What characterizes the existing City Hall's iconic appearance is the horizontal quality of the four floor high mass, defined by the repetition of vertical piers made of granite. For our new perimeter walls, we initially extended this horizontality with the same height louver screens on the south, west and north-west side where it directly connects to the existing structure. Therefore, the original façade horizontality has been extended from 123m to 248m, composing itself as the largest and the most prominent feature of the exterior amplifying the existing iconic quality of the old. For openness and accessibilty, the first floor of these louver screens is open, matching the height of the City Hall's stylobate. This louver screen acts as an open exterior screen wall, setting the spatial boundary from the south and west entrances into the Madang. The vertical louvers on the southern entrance have 80cm wide LED screens installed on one side, and when 35 of these elements rotate perpendicularly, they form a 15.8m high, 28m wide, extra-large projection screen towards the Seoul Plaza. This will be effectively used as a focal componant for frequent public functions, such as street-cheering and festivities. On the western entrance, the louvers will extend to the north-west corner where it becomes integrated as a curtain wall for the glass exterior of the symphony hall's foyer but more spaced out to emphasize the openness, and maintaining a smooth transfusion from the old to the new, and from opacity to transparency.

The rest of the elements of the wall extend past the 4th floor height, are composed of (mostly) building cores. Various forms of vertical components, such as circulation or utilities, are expressed in deviating degrees of opacity, while remaining consistent with the vertical louvers of the complex's exterior. As a result, the City Hall complex will be defined as a modulating 402m perimeter screen to the public.

Other Walls: Horizontal Elements
The Madang at the heart of the site will have its envelope defined by horizontal louvers of surrounding 9 floor mass and the two 18, 24 floor towers. The varying sloped surfaces that enclose the Madang are weaved together by these horizontal louvers, which extend upwards into subtle vertical masses. These louvers form the curtain wall that envelopes the interior spaces, as well as becoming open screens that define exterior terraces and even handrails. All the horizontal louvers will have granite on their underside such that the view looking up from the ground will directly make the connection with the existing City Hall's exterior and the vertical louvers of the perimeter wall. The top face of the louvers will be finished with acid-etched aluminum sheets, allowing for different variations. Specifically, photovoltaic panels are installed on all the southern louvers and planters on those that surround the courtyard at podium levels. The outdoor bridge on the south-west side of the courtyard (third, fourth and fifth floors) has Wind Capture louvers, which are activated to the specific seasonal conditions to control the airflow. The projection dimension of the louvers that surround the offices and other interior spaces are direction specific and allows for effective daylight use throughout the year.

 

Unity and Multiplicity 3: Organic Expansion of Geometric Logic
Another factor that we had considered is the geometric logic of the existing City Hall, whose genetics become the basis that composes our proposal.

Seoul City Hall's Geometric Logic
The existing City Hall is a product of the Cartesian logic that forms the classicism of European architecture, with 45 degree corners that are angled in plan while maintaining the façade continuity in elevation. This coherence has been enhanced further by curving the sharp edges at the turning points, improving the continuity. This is a reason why most feel intimacy rather than overpowering, even though this is a heavy, opaque masonry building.

The Organic Expansion from the City Hall's Geometry
Besides the southwest corner where the existing structure is located, the other three conditions are all newly defined, similarly duplicated as curved 45 degree corners. Although the heights may vary, the vertical louver elements will form a congruency with the masonry columns of the existing corner, thus simulating a uniform external language. Additionally, all the walls are centrifugal from the Madang and follow a strict logic of perpendicular and 45 degrees, exhibiting the intention of manifesting out from the existing structure.

 

An Iconic Building that Represents "Place" Rather than "Object"
Seoul, against other fast-developing metropolises in Asia, is currently at fierce competition to raise an iconic structure to represent the city globally. The majority of these cases attempt to resolve this issue by creating a sculptural object of powerful aura, but this method remains effective only if there is suitable urban context to support and justify the addition. The specificity of Seoul near the City Hall causes discrepancy with this iconic approach, due to the complexity and the fast, compressed developmental nature (which becomes a common trait among contemporary Asian urban conditions). The new Seoul City Hall has thus far struggled, trying to incorporate a strong object-based architecture, and therefore had not been received with empathy due to it's rejection of—and from—the site. Additionally, there had not been a clear enough vision to engage the old iconic City Hall building with the new structure which would inevitably be overpowering in scale. Therefore, we are suggesting an alternative proposal that focuses on remaining respectful to the underlying context of the old structure and its vicinity, to optimize their conditions and enhance their advantages by becoming an ensemble that is unobstructively synthesized.

As a result from our previously stated strategies of unity and multiplicity, the space that works as a "place" rather than an "object" is the City Hall Madang, the courtyard space.

Our proposal for the City Hall is not an object-based architecture that is quick to reveal all of its virtues from several kilometers away, but a spatial experience that is fully integrated into the city to be re-discovered as a 'place.' The exterior forms an appropriate composition with the surroundings, with unique and inviting urban elements as a unified whole from all sides. If the existing City Hall building could be generalized as a façade, or simply, a single face, then the new proposal could be understood as a continuing array of faces whose dynamic quality would draw the people in from all directions. Once they are inside, they will be submerged into the strong, central outdoor space of the Madang, re-defining the space as a dynamic interaction of public functions. Through this Madang, the City Hall will become one, while the exterior is composed of multiple traits to embrace different types of people, and thus interact with each of their daily lives.

Project:
New Seoul City Hall:
Unity and Multiplicity

Design Period:
2007.12 – 2008.2

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Type:
Civic (Competition)

Location:
Seoul, Korea

Site Area:
12709.4 ㎡

Site Coverage Area:
7520.4 ㎡

Total Floor Area:
94398.1 ㎡

Building-to-Land Ratio:
59.2%

Floor Area Ratio:
486.0%

Building Scope:
24F, B5

Structure:
SRC+RC

Finish:
Double Glazed Low-E Glass
Granite Stone
Acid Etched Aluminum Plate

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Architects:
Mass Studies
Minsuk Cho, Kisu Park, Joungwon Lee, Hyunseok Jung, Joonhee Lee, Hyunjung Kim, Sangkyu Jeon, Jongseo Kim, Bumhyun Chun, Ranhee Kim, Wonbang Kim, Sungpil Won, Dongwon Yoon, Jonas Eppen, Vin Kim, Jieun Lee, Jisoo Kim, Chungwhan Park, Moonhee Han, Jangwon Choi

Structural Engineer:
Ove Arup & Partners

MEP Engineer:
Ove Arup & Partners

Local Structural Adviser:
TEO Structure

Local MEP Adviser:
HANA Consulting & Engineers

Client:
The Seoul Metropolitan Government