A construction site for GS E&C's Pohang Xi Atherton in Pohang, North Gyeongsang Province, Dec. 4, 2023 / Courtesy of Pohang Bukbu Fire Station

GS E&C and Kyeryong Construction Industrial were reported as being builders in the country with the largest number of apartments having defects in the past five years, according to the Ministry of Land, Infrastructure and Transport, Sunday.

From January 2019 to last month, the ministry's Apartment Defect Dispute Mediation Committee received 901 reports about apartment defects built by GS E&C. Including all subcategories of defects in detail, the total number of defects reached 3,284.

After the committee followed up on the reports by conducting on-site inspections, it confirmed that 391 of the reports, were actually valid in their claims about defects.

GS currently oversees 124 ongoing apartment projects.

During the same period, Kyeryong received 1,002 reports of apartment defects and the committee confirmed 533 of them. The number of apartment projects now led by the company is 14.

The two companies took the top two positions last September when the committee released — for the first time — the country's top 20 construction companies with the most apartment defect reports. The authority did so to raise public awareness of the dangers of hazardous apartment construction.

In the committee's latest report, the two companies were followed by Daebang Construction with 513 confirmed defects, SM Woobang with 413 and Daemyung E&C with 368.

Twenty companies in the committee's latest list received a total of 11,803 defect reports during the period. The committee has found that 55 percent of them had actual defects. The most frequent type of defects were: technical malfunctions (10.1 percent), cracks (9.1 percent), flooring issues (9.1 percent), condensation on walls or ceiling (7.5 percent) and leaks (6.1 percent).

The ministry said the committee put in force a revised regulation on Tuesday that the committee will take no longer than 30 days to confirm reports on serious apartment defects like cracks on reinforced concrete, exposed rebar, structure cracks and settlement.

"We're making this data public to induce the country's construction firms to improve quality in their apartments and raise awarenes on more citizens here," a ministry official said.