DL E&C Solves Vertical Extension Challenge...Develops New Construction Technology

First Domestic Development of Post-Tensioning Construction Method
Omission of New Technology and Method Verification Stage Possible
Project Duration Reduced by Over One Year

DL E&C has developed a construction method that can solve the structural safety issues, considered the biggest technical challenge in vertical extension remodeling of apartment complexes, for the first time in the domestic construction industry.

Post-tension load transfer method. (Provided by DL E&C)

DL E&C announced on the 7th that it succeeded in developing the 'Post-Tension Load Transfer Method' and obtained the Ministry of Land, Infrastructure and Transport's construction new technology certification (No. 964) for the first time in the industry. This is the first case in Korea where a foundation reinforcement method for vertical extension remodeling received new construction technology certification from the Ministry of Land, Infrastructure and Transport.

Solving Challenges with Differentiated Technology... Up to 3 Additional Floors Can Be Added to Apartments

Unlike typical vertical extensions, vertical extension remodeling allows adding up to three additional floors to an apartment, maximizing profitability. However, when increasing the number of floors, securing safety has been difficult due to load distribution issues, causing vertical extension projects to progress slowly. Various methods were proposed to solve the problem, but they failed to pass technical verification and safety reviews. As a result, most associations either abandoned the projects or had to switch to horizontal or separate building extensions.

To disperse the load concentrated on some piles when adding floors, DL E&C came up with the idea of utilizing post-tension technology. The post-tension method uses the tension of steel tendons to support loads on building slabs or bridges and is used in super high-rise buildings, nuclear power plants, and bridge construction.

DL E&C succeeded in controlling the load on piles by installing steel tendons in the basement walls to transfer the load from the walls to the building foundation. This method secured safety by appropriately distributing the increased load to existing piles while minimizing the reinforcement of new piles.

Professor Kang Hyun-gu of Seoul National University, who conducted the technical verification research on the post-tension load transfer method, said, "DL E&C has overcome the technical limits of vertical extension remodeling by proposing a method that was previously unimaginable," adding, "This method is an innovative technology that can bring a new wave to the remodeling market."

Review Period Reduced by Over a Year... Achieving Both Safety and Business Feasibility

After developing the post-tension load transfer method last year, DL E&C was the first to obtain performance verification and technical certification from the Korean Concrete Institute. Additionally, through technical verification by LERA, a world-renowned structural design firm involved in projects such as the New York World Trade Center, Shanghai International Financial Center, and Jamsil Lotte Tower, it was certified to comply with international design standards including the IEBC (International Existing Building Code).

With the recent certification from the Ministry of Land, Infrastructure and Transport, DL E&C can now skip the technical certification process by authorized institutions required for vertical extension remodeling projects. This is expected to significantly shorten remodeling project periods by reducing safety review times, which typically take at least one year.

DL E&C plans to leverage this new technology to lead the domestic remodeling market. Previously, DL E&C successfully completed Korea's first apartment remodeling project, Mapo Yonggang Apartment (Gangbyeon Green), as well as Apgujeong Hyundai Employee Apartment (Daelim Acroville) and Ichon-dong Royal Mansion Apartment.

Since 2019, DL E&C has deployed 15 researchers and experts with master's and doctoral degrees to develop core remodeling technologies, including vertical extension, inter-floor soundproofing, underground parking, and structural reinforcement. Furthermore, to expand remodeling projects, DL E&C has established a collaborative system with LERA and is actively moving to expand its business based on technological superiority. This year, it plans to focus its capabilities on securing projects such as Sadang Jeil and Ilsan Hugok 11 and 12 complexes.

Lee Sang-jin, Executive Director of Housing Technology Development at DL E&C, said, "DL E&C has taken a step ahead in technological competitiveness in the market by solving the challenges of vertical extension remodeling of apartment complexes that other construction companies could not solve," adding, "We plan to focus on the remodeling market based on this new technology."