[Boomerang of High-Density Apartments ①] 120,000 Units with 300% FAR to Reach Reconstruction Threshold by 2030... Seoul’s 'Apartment Republic' Hits Its Limit

In 25 Districts, 28 Complexes Reach Reconstruction Threshold
By 2030, 251 Complexes Will Be Eligible for Redevelopment
Overcrowded Apartments Face Challenges Securing Units for Public Sale
Safety and Residential Environment Deterioration Al

The fastest solution to Seoul's housing shortage in the 1990s was the construction of high-density apartment complexes. In line with then-President Roh Tae-woo’s “Two Million Housing Units Construction Plan,” apartment complexes with floor area ratios (FARs) approaching 400% began to spring up across Seoul. The unique characteristics of each area and the capacity limits of infrastructure, such as road networks, were not considered. At that time, the priority was on how quickly as many housing units as possible could be supplied in a short period.

Now, more than 30 years later, Seoul is facing the consequences of “high-density apartment aging.” In the next five years, approximately 126,000 units in 251 complexes—each with a floor area ratio above 300%—will reach the legal age for reconstruction. Since these apartments were already built with high floor area ratios, a significant number of them are expected to have difficulty securing sufficient units for general sale, making reconstruction challenging. However, the issue of aging high-density apartments is not just about whether reconstruction is possible. The dense clusters of high-rise, high-density apartments in the city center are also linked to future urban environmental challenges. If left unattended due to limited profitability caused by restrictions such as floor area ratios, the city environment could deteriorate. This is why a broader perspective is required when addressing housing issues in metropolitan areas like Seoul and its surroundings. This series will examine the issue of aging high-density apartments and possible solutions in three installments. <Editor’s Note>

It has been found that the number of apartment units with a floor area ratio (the ratio of total floor area to the size of the land parcel) of 300% or more that will reach the reconstruction threshold within the next five years exceeds 120,000. Up to this year, only 11,277 apartment units with an FAR above 300% have surpassed the legally mandated period for reconstruction, but this figure is expected to increase tenfold over the next five years. Especially considering that most newly built apartments in recent years have an FAR approaching 300%, the number of units eligible for reconstruction is expected to rise even further. Since most of these apartments will struggle to ensure business viability for reconstruction without measures such as FAR relaxation or zoning upgrades, early preparation is urged as the issue could escalate into a social problem.

According to a comprehensive analysis by The Asia Business Daily of building registers in Seoul using the Ministry of Land, Infrastructure and Transport’s Construction Hub, there are a total of 530 complexes—comprising 234,178 units—that were approved for completion since 1990 and have an FAR exceeding 300%. Among these, 28 complexes with 11,277 units were completed before 1996 and have reached the reconstruction threshold as of this year. If the scope is extended to complexes that will reach the threshold within the next five years, the numbers increase to 223 complexes and 114,828 units. In other words, by 2030, a total of 251 complexes with 126,105 high-density apartment units in Seoul will be subject to possible reconstruction.

According to the Seoul Metropolitan Government’s Urban and Residential Environment Improvement Ordinance, buildings with five or more stories constructed after 1986 must meet one of two requirements to be eligible for reconstruction: more than 30 years since completion and either a site area of 10,000 square meters or more, or a total of 200 or more units.

The reason for the focus on high-density apartments is that, except for a very few cases, most of these complexes will find it difficult to pursue reconstruction through private initiatives. The viability of reconstruction projects is directly tied to the existing floor area ratio. Complexes with lower FARs can secure more units for general sale through reconstruction, thereby lowering the financial burden on member owners. In contrast, high-density apartments have limited capacity to secure such units. To make matters worse, the aftermath of the Middle East conflict has sent construction material prices soaring. As a result, the construction cost burden on owners has already increased significantly. Baek Jun, CEO of J&K Urban Renewal, said, “In complexes with an FAR exceeding 270%, excluding public contributions, in most cases you cannot even rebuild the same number of units as currently exist,” adding, “Even one-to-one reconstruction is difficult in these cases.”

If the maintenance projects for these apartments are delayed for a long period due to insufficient viability, it may pose a safety risk for residents. Safety issues are already emerging in aging high-density complexes. For example, Eunma Apartment in Daechi-dong, Gangnam-gu, where a fire in February resulted in one death, was completed before the installation of sprinklers became mandatory, leaving it without adequate fire prevention facilities. Similarly, Daesang Town Hyundai Apartment in Banghak-dong, where a 2023 fire led to two deaths and 30 injuries, was also built before sprinklers were required for buildings with more than 16 stories, leaving the lower floors—where the fire broke out—in a safety blind spot.

Deterioration of the living environment is another problem. High-density apartments designed to accommodate many households inevitably see rapid aging of common areas and infrastructure. Residents of complexes approaching 30 years since completion complain of issues such as corroded pipes, water leaks, and parking shortages. Resident B of Apartment A in Mapo-gu, which marks its 32nd year since completion this year, said, “My quality of life has declined due to water leakage on the exterior walls, low ceiling heights, and double parking problems, so I’m considering moving,” adding, “With the aging pipes, foul odors rise up through the bathroom, making it hard to bear without a drain trap.”

Experts warn that the aging of high-density apartments could, in the long term, lead to urban slumification. Lee Taehee, Associate Research Fellow at the Korea Research Institute for Construction Policy, said, “Compared to Japan, which faced the issue of aging multi-family housing earlier, Korea collects relatively small sums for long-term repair reserves, so some complexes may eventually find it impossible to cover maintenance expenses as aging progresses. If these complexes are left unattended for a long time due to lack of business viability, slumification could damage the urban landscape.”

This content was produced with the assistance of AI translation services.