Three Floors Added from Ground Floor to 18th Floor, Transformed into 327 Units
Passed Strict Vertical Expansion Safety Standards
The appearance of the remodeled complex ‘Jamsil The Shop Reuben,’ completed through a ‘vertical expansion’. [Provided by POSCO E&C]
[Herald Economic = Reporter Hong Seung-hee] POSCO E&C announced on the 17th that it has completed the construction of ‘Jamsil The Shop Reuben’, the first vertically expanded apartment complex in Korea, and started moving in from the 7th.
This complex, located in Songpa-dong, Songpa-gu, Seoul, is a remodel of the Sungji Apartment, completed in 1992, via vertical expansion. After the business plan was approved in 2020, construction began in January 2022 and was newly born in March 2025 after 38 months of work.
The apartment was transformed from the existing two buildings with 2 basement floors and 15 upper floors, housing 298 units, into buildings with 3 basement floors and 18 upper floors, housing 327 units, with the increase of 29 units completed through general sales.
The significance of Jamsil The Shop Reuben lies in being the first complex in the country to have 3 floors vertically expanded. ‘Vertical expansion’ refers to the remodeling method where the number of floors in a building is extended upwards, allowing up to 2 additional floors if the existing floors are below 15 and up to 3 additional floors if 15 or above.
While it has advantages such as maintaining existing building layout and ensuring views without interference, it requires high technical competency due to the application of stricter structural safety standards including two safety reviews.
To distribute the additional load from the three-floor vertical expansion, POSCO E&C conducted challenging foundational reinforcement works sharing the load on a solid foundation. The ‘floating structure method,’ supported by reinforced piles, was applied in elevator installation zones where existing structures’ sub-bases had to be excavated. In areas lacking bearing capacity, the ‘load-bearing base foundation method’ extending to firm ground, and the ‘base reinforcement method’ thickening with additional concrete casting were employed to reinforce the base.
Furthermore, to firmly connect the new and old structures, a ‘new-old structure connection composite method’ was applied, welding the reinforcing bars of both structures and fixing them with chemical anchors.
Smart construction technology was also utilized by precisely measuring the existing building with 3D scanning, simulating it using BIM (Building Information Modeling), introducing a real-time monitoring measurement system, reviewing optimal demolition methods, and ensuring precision construction to secure safety.
Meanwhile, POSCO E&C has been selected as the constructor for six public-supported remodeling complexes in Seongnam City, including Rainbow Village Phase 4 and Neuti Village Phases 3 and 4, and plans to gradually commence general sales this year. Also, having secured its first contract of the year with the Sangnok Tower Apartment remodeling project in Gwangjang-dong, Seoul, in January, and competing individually for the largest remodeling project in the Gangnam area like the Isu Geukdong and Wuseong Phases 2 and 3 complexes, POSCO E&C plans to further widen its lead over competitors as a remodeling powerhouse.