A Korea Land & Housing Corp. (LH) official demonstrates how noise-proof technology reduces various types of noise generated in an apartment unit inside one of the testing rooms at DB35Lab in Sejong, Thursday. Courtesy of LH
One of the mock apartment buildings inside DB35Lab in Sejong / Korea Times photo by Ko Dong-hwan
Korea Land & Housing Corp. (LH) is realizing its mission to introduce noise-proof apartment units to residents in the country as noise disturbances caused by neighboring residents in an apartment or residential building — sometimes causing conflicts that lead to fatal casualties — has been a chronic issue, according to the state-run public housing provider, Thursday.
The company under the Ministry of Land, Infrastructure and Transport plans to introduce LH's "first-grade" noise-proof technology to newly designed apartment buildings starting in the second half of the next year. By further advancing the technologies, LH said it will be able to reduce costs of implementing the technology in any apartment construction project and prevent it from becoming a financial burden to those wishing to live in a quiet, "library-like" apartment unit.
At the core of the technologies are advancing qualities of cushioning materials and mortar above a concrete slab so that any noise that transmits through a floor becomes low enough to be almost inaudible. LH anticipates that with the technologies, noises that transmit through floors below will be 37 decibels or lower.
According to LH's noise categories, establishing soundproofing of 37 decibels or lower are first-grade quality, while 37-41 are second grade, 41-45 third grade and 45-49 fourth grade. Any sound above that can be unbearable for apartment units below.
Lowering apartment noise requires raising the density of cushioning materials and mortar. Using high-quality materials for the sections helps, but they pull up the overall construction costs.
Another method is raising slab thickness from the current minimum of 21 centimeters to 25 centimeters. Installing water pipes within each apartment unit instead of through a floor to lower units is another way to achieve the purpose.
Implementing those technologies can achieve first-grade noise-proof quality, according to LH. In existing apartments in the country with fourth-grade quality, density of cushioning materials and mortar is low and the slab is no thicker than 21 centimeters.
Higher-density materials and thicker slabs are used for first-grade noise-proof flooring, right, compared to flooring with fourth-grade quality, left, as shown by cross-sections of floor layers, inside DB35Lab in Sejong. Courtesy of LH
LH CEO Lee Han-joon speaks during a press conference in Sejong, Thursday. Courtesy of LH
There is more than one way to improve density of cushioning materials and mortar. Not only LH but private construction companies are doing research for the same purpose, having introduced different solutions. LH has selected six of them and, by adding its own technologies, it plans to commercialize the solutions for new apartment construction projects starting next year.
Testing the solutions takes place at DB35Lab which is LH's new noise-proof testing facility for apartments in Sejong. The facility consists of 10 apartment units in three mock apartment buildings. The buildings were built in either bearing wall structure — an aged method currently being phased out in Korea — or rahmen structure, an increasingly in-demand method nowadays.
The facility showcases different solutions for floor layering which have been developed by private firms. At a mock living room and kitchen inside the facility, various noise-generating activities — running on a treadmill, dropping a heavy rubber ball on the floor, dragging a chair, turning a kitchen fan on at varying strengths — are tested to observe how many decibels they generate through the floor.
"We have conducted more than 1,347 tests to achieve our first-grade noise-proof floor model," Jung Wun-seob, vice president of LH's smart construction division, said in Sejong. "We've been testing them since 2022. The technology is applicable to various apartment types including modular structures."
The facility will be completed next March. LH said it will enable noise-proof technologies' certification in the country to take less than six months. Currently, the process takes more than a year.
DB35Lab will be open to private companies so that it can provide support particularly for small and medium-sized enterprises with low budgets by allowing them to test their own technologies and share LH's own advancements as well.
"Since LH had ushered in apartments in Korea decades ago for the first time, it's our duty and top priority to achieve noise-proof apartments," LH CEO Lee Han-joon said during a press conference in Sejong.
"Apartment construction methods must change. Now, all apartments must be demolished after 30 years and rebuilt. Instead, we need longer-lasting apartments. Rahmen, for example, lasts for 100 years. The noise-proof technology will raise the costs of apartment construction but not too excessively on the builder's part. We might come up with technologies that allow making even thinner floor layering that still guarantees the same noise-proof quality."