Data Center: New Architectural Typology Faced with Challenges and Limitations: NAVER Data Center GAK Sejong Sever Building & Operation Building

SPACE December 2023 (No. 673) 

[PROJECT] New Types of Architecture​​

There are types of architecture that represent a cross-section of an era. These include the cathedrals of religion-oriented medieval Europe and the factories for mass production and tenement housing (multi-family housing) for workers that emerged during the Industrial Revolution. Applying such a perspective directly, perhaps a new type of architecture that reflects the current era of technology and information is the data center: a computing space operated by governments, businesses and research organisations that has grown rapidly with the commercialisation of the internet and the development of mobile technology, and has become an essential infrastructure. With rapid advances in technology, people are also predicting the future of data centers in two main directions: either they will end up being concentrated in the form of a mega-sized individual or clustered form, or they will shrink to the point that they have no physical form as information is distributed through blockchain technology. On the other hand, social awareness of data centers in Korea is still at a low level. Relevant laws and ordinances have only recently been implemented. In 2018, data centers were added to the list of building uses regulated by the Building Act as ‘broadcasting and telecommunications facilities’, but there is still a lack of coordination with energy-related laws and local government ordinances. This shows that the significance of the data center industry is still underestimated.

There are many ways to differentiate data centers. In the field of architectural design, data centers can be divided into enterprise data centers and commercial or internet data centers.^▼1 NAVER Data Center GAK Sejong (hereinafter GAK Sejong) is an enterprise data center that was created with an independent concept and philosophy based on people, environment and technology. GAK Chuncheon (2013), as NAVER’s first enterprise data center before GAK Sejong, faithfully served as a storage facility for the safekeeping of intangible valuables, while GAK Sejong has expanded its meaning and function to become a data center closer to everyday life. With the outbreak of the Coronavirus Disease-19 at the time GAK Sejong was being designed, the entire world experienced the potential of overcoming the limitations of physical activities through information technology. Today, as the data center emerges as a new type of architecture, we hope that the discussion of GAK Sejong can stimulate such an architectural discourse and encourage the exploration of various possibilities.

Sketch of layout study in early stage​

Master Plan

On a site of 293,697m2, GAK Sejong consists of a Server Building, an Operation Building, an Staff  Accommodation Building and two Information Buildings. In the early stages of setting out the master plan, we studied various scenarios using the network topology,^▼2 starting from the relationship between major programmes such as the Server Building and operation facilities, without considering the context. After selecting the topologies that would best suit the ordering organisation’s way of operation, the design was developed and the scattered masses were organised into two large clusters that interlocked in an arc. The final site is located on a steep slope where a watercourse flows from Buryongsan Mountain to the Geumgang River. In order to take advantage of the valley wind from the watercourse for natural ventilation, the main task was to locate the Server Building and the Operation Building on both sides of the valley and to connect them functionally. As a large facility developed on an urban scale in a natural environment, environmental issues were inevitable from the start of the project. We therefore considered a phased development to maximise the conservation area and concentrate the main facilities together.

During the design phase, we also carried out thorough preliminary studies, including ecological and vegetation surveys, to ensure that the civil and landscape plans that physically connect the facilities would not disrupt or isolate existing environmental flows. In addition to environmental issues, the multidisciplinary complexity and special features of the data center required preliminary research and consultation at every phase. In particular, we worked closely with experts in specialist areas such as noise impact analysis, solar impact analysis, CFD (Computational Fluid Dynamics) simulation, external air impact CFD, site specific seismic hazard, risk factor assessment, emergency planning, and security. It can be said that the design process of GAK Sejong has been a continuous orchestration.

Server Building: Space Dedicated to Servers

When data centers are described in terms of their size, they are often described in terms of power capacity rather than area. GAK Sejong, in its final form after phased expansion, is estimated to be the largest in Asia with 270MW of received power amount. Ironically, the more data we collect that does not occupy physical space, the more physical space and power requirements increase in direct proportion, and this has interesting implications. The current aim of the technical skills in data center operations is to install as many servers as possible in a large space to ensure operational variability and flexibility, and to maintain an appropriate temperature by managing the heat load emitted by energy (power) consuming servers. Therefore, data centers require a larger void volume than general buildings, from floor height to structural span, loading dock, elevator size, door width and height, and hardware, and the size and quantity of MEPF (Mechanical, Electrical, Plumbing, and Fire Protection) equipment due to the large energy demand reaches the level of urban infrastructure.

The Server Building, the core facility, is a hyperscale data center with three underground floors of mechanical and electrical rooms and two ground floors of server rooms. Architecturally, the Server Building starts with racks in a floor area of 600 × 1,200mm. These racks come together to form a single row, and the rows come together to form a single zone. Once you have seven or eight of these zones, you have a server room. Once the racks were determined, the electric capacity (capacitance) per rack was determined and the total volume was adjusted by laying out and compartmentalising the number of racks and server rooms according to the capacity required by the ordering organisation. The lowest floor was mostly planned as a water tank for cooling the server rooms, the second basement floor for the mechanical rooms and the first basement floor for the electrical rooms. Water-intensive equipment was placed on the lower floors, while power-intensive equipment was placed on the upper floors to prevent safety accidents during data center operations.

The ground floor of the Server Building consists mainly of server rooms. NAMU (Naver Air Membrane Unit), NAVER’s independent technology for reducing the heat load of the server room, is used to channel the outside air into running water to maintain the proper constant temperature and humidity through evaporation. In the end, it took a lot of discussion to design the elevation to smoothly bring in outside air and to design the layout to take into account the microclimate of the site. As a result, most of the front and back of the Server Building is designed to breath-in, while the air-conditioning tower on the roof is designed to breathe-out.

In line with the master plan, we aimed to create ‘architecture as a backdrop’, where the main facilities do not stand out but blend in with their surroundings. By using exposed concrete for the exterior finish of the Server Building’s lower floor, we thought about structural safety and natural harmony with regional ecological elements. The Server Building’s lower floor itself is both a podium to support the data center and a retaining wall to withstand the lateral forces of the sloping site, so the texture and materiality of the concrete exterior wall serve a dual purpose. On the other hand, the upper floor of the Server Building is made of lightweight and durable aluminium panels, which are not painted but anodised with a surface oxidation treatment. All exterior finishes in the main facilities are functional rather than showy. In particular, the elevations have been designed to blend in with the surroundings as much as possible without overpowering the huge mass of the Server Building.

Operation Building: A Space Dedicated to Working People

While the Server Building is a space on a machine scale, the Operation Building is a space for people working in shifts around the clock. While the Server Building focused rationally on quantitative values based on data, the Operation Building considered more qualitative values based on human emotions and the humanities. In particular, the size and nature of the space was designed to connect the workers’ workstations to the natural environment surrounding the site. It was hoped that the fatigue and hardship felt in the mechanical Server Building would be alleviated by workstations exposed to nature. The underground floor of the Operation Building consists of the MEPF facility space and parking, which is physically connected to the Server Building, and from the first basement to the ground floor is a business and public space for data center operations. The ground floor is also connected to the Server Building by a bridge so that data center managers can respond quickly to various operational situations without having to go outside. The lobby area on the first basement floor takes advantage of the slope of the site and the courtyard on the lower floor to provide ample light and ventilation.

The 154kV power receiving facilities, which can be described as the heart of the hyperscale data center, is located in the underground space of the Operation Building, protected by a double slab. The 154kV power in the electrical room is reduced to 22.9kV, and 380V is transmitted through the Server Building’s Spine (MEP corridor) to each server room via the Server Building’s electrical room. This is similar to installing an urban-infrastructural scale substation in the underground space of the Operation Building and connecting it to the Server Building via a common underground duct that acts as a transmission tower. The layout of the MEPF’s pipework, equipment trays and ducts, which are as varied and complex as the enormous scale of the mechanical, electrical and fire protection equipment, was simulated in BIM to avoid interference with the architecture and structure and to find hidden spaces for equipment.

Models of layout study in early stage​ / Image courtesy of Junglim Architecture​

The Coexistence of Technology and Robotics

In addition to the technology to control the environment of the data center’s server rooms, GAK Sejong is equipped with robots and autonomous driving technology for data center operations. Robots operate both indoors and outdoors, and autonomous vehicles are used outdoors, while three types of indoor robots have been developed, which are transport robots that move between server rooms and storage rooms, robots that operate data center storage rooms, and robots that scan and monitor server room equipment. In order to provide space for such technologies and to increase the usability of the robots, the architectural design primarily started with the smooth movement of the robots. In the early stages of the design, there was a lack of design standards for robots, so NAVER Labs researchers regularly attended meetings to discuss what technologies should be included in the architecture. Due to the nature of wheeled robots, we began by introducing a barrier-free design that would be accessible to wheelchairs. In the later stages of the design, we selected flooring finishes that were wheelchair accessible and minimised differences in floor levels such as thresholds and stairs, and vertically, we provided passenger and freight lifts and robotic communication infrastructure to combine different robotic technologies such as equipment transport, user guidance, and indoor and outdoor movement. QR-coded signage was also developed with partners to help robots recognise space and orientation. 

GAK Sejong is a place of coexistence for robots and humans. While architecture has traditionally been designed from a human perspective, GAK Sejong required a new approach to consider a robot’s perspective. The process of incorporating futuristic technology into architecture was not easy. Thinking about future technologies in the early stages of design and planning should be open to as many potentials as possible, but when it comes to implementing them in the actual design, appropriate technologies must be selected that take into account the constraints of real-life and the time of the project’s operation. Architecture should be thinking about how and to what extent to incorporate technology, rather than the development of technology itself. The time has come for architecture and technology to work together. We hope that GAK Sejong will further expand this collaboration.​

(from left to right)​ Aerial view rendering of winning proposal (design competition stage 2)​, Final aerial view rendering, Final model / Image courtesy of Junglim Architecture​​

1.  In Korea, internet data centers are commonly referred to as CDC (Collocation Data Center) rather than IDC.

2.  In IT terminology, this refers to the physical and logical interconnective structure of network elements. Physical topology refers to the structure that physically arranges and connects different network nodes (or devices) and the links (or communication lines) between them. Sources: IT Glossary, Telecommunications Technology Association.​