[Constructionin] "Modular, Technology Comes Before Profitability... Pursuing Innovative Construction Methods"

Sangjin Lee, Executive Director of Future Technology Center, DL E&C Housing Business Division
"Optimization of Modular Unit Factory... Technology Determines Competitiveness"
Modular Housing in Buyeo... Expected Entry into Small-Scale Housing Market

Editor's Note'Geonseolin' is an interview series that focuses on individuals active in the construction industry. We aim to deliver vivid industry stories by meeting construction professionals who stand out in various fields such as core businesses and new growth engines of construction companies.

Lee Sang-jin, Executive Director of the Future Technology Center at DL E&C's Housing Business Division, is discussing the achievements in modular housing construction in an interview with Asia Economy. / Photo by DL E&C

"If we are building modular buildings, shouldn't the unit (structural component) production method also be different?"

Lee Sang-jin, Executive Director of the Future Technology Center at DL E&C's Housing Business Division, recently said in an interview with this publication, "Our initial approach to modular construction was based on 'technological capability,' not business feasibility."

Modular construction is not a common building technique in Korea. It is a cutting-edge method that is gradually being activated as the construction industry practices Environmental, Social, and Governance (ESG) management. Using this method ensures uniform quality and reduces waste generated during construction. Minimizing on-site work shortens construction periods and reduces safety accident risks. In the long term, it also has the advantage of reducing defect repairs.

Building modular housing is similar to assembling a robot. To complete a house, you need a roof, floor, and rooms such as bedrooms, living rooms, and bathrooms divided according to their use. The framework (units) for these components is manufactured in a factory and then transported to the site for assembly according to the design.

Executive Director Lee emphasized that DL E&C's modular method is differentiated from other construction companies. He explained, "I toured modular factories that produce units, and contrary to expectations, the work at the site was only preceded by factory work. We aimed to optimize the unit production method at the factory as well. Technically, we increased productivity through standardization of work processes rather than conventional simple manufacturing." He added, "The method of building houses is the same for all construction companies, and subcontractors are shared. Ultimately, technical capability will distinguish fundamental competitiveness," emphasizing that "innovative construction method changes are a major goal."

A modular detached housing complex built in Sandong-myeon, Gurye-gun, Jeollanam-do / Photo by DL E&C

DL E&C has a track record of demonstrating modular units for apartment ancillary facilities. In 2020, they built a modular security office for an apartment in Gimpo, marking the first case in Korea. Last year, they completed a modular single-family housing complex in Sandong-myeon, Gurye-gun, Jeollanam-do. This is significant as it is the first housing in Korea completed by combining a total of 11 steel units.

The construction process could be viewed through a time-lapse video. The units fit together to form the shape of the house. Tasks such as wallpapering and painting were done on-site. Executive Director Lee analyzed, "Nineteen patented technologies independently developed by DL E&C were applied, improving productivity by 125%, including a 50% reduction in structural production time and a 40% reduction in finishing production time." He added, "In bidding, designs that ensure uniform quality rather than flashy aesthetics were more persuasive." He recalled, "The joints between units are so seamless that unless you deliberately look for them, they are hardly noticeable. This is hard to experience on-site, and residents expressed their gratitude, saying 'Thank you for building the house well.'"

Executive Director Lee expects modular construction to provide large construction companies with opportunities to enter the small-scale housing market. He said, "In the case of single-family housing projects, the land sales scale is so small that large construction companies have not entered, but modular construction will make it possible." However, he noted that there are still cost limitations to building high-rise buildings like apartments using modular methods. He also added that regulatory standards for fire resistance and earthquake resistance remain unclear.

DL E&C is currently building new modular housing in Dongnam-ri, Buyeo-gun, Chungnam. Executive Director Lee said, "When construction costs such as labor were not expensive, the domestic construction industry did not feel the need, but in the mid to long term, it will inevitably shift to modular construction," adding, "Once modular construction becomes full-scale, DL E&C, which has accumulated technological capabilities, will take the lead."