[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 the Roh Tae-woo administration's “Two Million Homes Construction Plan,” apartment complexes with floor area ratios (FAR) approaching 400% began to rise across Seoul. The limitations posed by local topography or infrastructure, such as road networks, were not taken into account. The top priority at the time was how quickly a large number of homes could be supplied in a short period.

Now, more than 30 years later, Seoul is facing the consequences in the form of “high-density apartment aging.” Over the next five years, approximately 126,000 apartment units—across 251 complexes—with an FAR greater than 300% will reach the statutory age for reconstruction. Because many of these were already built at very high density, a significant number are unlikely to secure sufficient units for general sale, making reconstruction a challenge. However, the issue of high-density apartment aging is not just about whether or not reconstruction is possible. High-rise, high-density apartments densely packed in urban areas also present risks for the future urban environment. If these complexes are neglected due to limited business feasibility resulting from FAR restrictions, the urban environment could deteriorate further. This is why it is important to take a broader view of housing issues in major cities like Seoul and their surrounding areas. This series will examine the problems and potential solutions regarding aging high-density apartments in three parts. <Editor’s Note>

It has been found that the number of apartment units with a floor area ratio of 300% or higher, which are more than 30 years old and will reach the statutory reconstruction period within the next five years, exceeds 120,000. While only 11,277 apartment units with an FAR over 300% have exceeded the reconstruction period as of this year, that number is expected to increase tenfold over the next five years. Moreover, considering that most newly built apartments in recent years have an FAR close to 300%, the number of units eligible for reconstruction is projected to rise even further. As these apartments will struggle to ensure business feasibility during reconstruction without measures such as FAR relaxation or zoning upgrades, there are growing calls to proactively prepare for what could become a major social issue.

According to a full analysis conducted by The Asia Business Daily on June 17—using building ledger data from the Ministry of Land, Infrastructure, and Transport’s Construction Hub—there are a total of 530 apartment complexes, comprising 234,178 units in Seoul, that received construction approval since 1990 and have an FAR of 300% or higher. Of these, 28 complexes, or 11,277 units, were completed before 1996 and have reached the statutory reconstruction period as of this year. If the scope is expanded to include complexes that will reach the reconstruction period within the next five years, the number rises to 223 complexes, or 114,828 units. In summary, by 2030, a total of 251 complexes and 126,105 units of high-density apartments in Seoul will be eligible for reconstruction.

According to the Seoul Metropolitan Government’s Urban and Residential Environment Improvement Ordinance, buildings with five or more floors constructed after 1986 must satisfy at least one of the following requirements to be eligible for reconstruction after 30 years: a site area of at least 10,000 square meters or at least 200 residential units.

The reason high-density apartments are attracting attention is that, with few exceptions, most of these complexes are unlikely to find a path forward through private-sector reconstruction. The business feasibility of reconstruction is directly tied to the existing floor area ratio. Complexes with lower FARs can secure a significant number of units for general sale during reconstruction, thereby reducing the financial burden on current homeowners. In contrast, high-density apartments are limited in the number of units they can make available for general sale. On top of this, material costs have skyrocketed due to the impact of the Middle East conflicts, further increasing construction costs for residents. Jun Baek, CEO of J&K Urban Renewal, said, “In complexes with an FAR above 270%, it is usually impossible to reconstruct the same number of units in the same size, except for those to be donated to the public,” adding, “Even one-for-one reconstruction is difficult in most cases.”

If the maintenance of these apartments is delayed for a long period due to insufficient business feasibility, it could pose safety risks to residents. Safety problems have already been reported in aging high-density complexes. For example, Eunma Apartment in Daechi-dong, Gangnam-gu, where a fire in February claimed one life, was completed before sprinkler installation became mandatory, resulting in inadequate fire safety equipment. Similarly, the Daesang Town Hyundai Apartment in Banghak-dong, where a 2023 fire killed two people and injured 30, was built before sprinklers were required for buildings taller than 16 floors, leaving the lower floors where the fire broke out without adequate fire protection.

Deteriorating residential environments are another concern. High-density apartments, designed to house large numbers of residents, experience rapid aging of shared spaces and basic infrastructure. Residents in complexes around 30 years old frequently complain of pipe corrosion, leaks, and parking shortages. One resident, Mr. B, of an apartment in Mapo-gu that is now 32 years old, said, “I’m considering moving because of water leakage on the exterior walls, low ceiling height, and double parking issues, which have lowered my quality of life. The plumbing is so old that bathroom odors come up through the drains, and it’s nearly impossible to live without drain traps.”

Experts warn that the aging of high-density apartments could, in the long run, 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 apartment buildings earlier, Korea’s long-term repair reserve funds are much smaller. As a result, some complexes may reach a point where they can no longer afford repairs after a certain level of deterioration has set in. If these complexes are neglected for a long time due to a lack of business feasibility, this could eventually result in slumification that damages the city’s appearance.”

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