Noise between floors drives violent crime, but post-construction checks carry no teeth

As disputes over inter-floor noise continue to escalate into violent crimes between neighbors, a government mediation center has logged more than 350,000 phone consultations over the past decade.

Data obtained from the Korea Environment Corporation by Democratic Party of Korea lawmaker Hwang Hee of the National Assembly's Land, Infrastructure and Transport Committee show that the Inter-Floor Noise Neighbor Center received 355,047 first-stage phone consultations from 2016 through August this year. Annual figures have exceeded 30,000 every year — 46,596 in 2021, 43,930 in 2022, 36,435 in 2023, 33,027 in 2024 and 32,662 last year. Through August this year, the center had received 26,852 calls, averaging about 110 a day — equivalent to 82.2 percent of last year's full-year total.

The center supports conflict resolution through first-stage phone consultations and second-stage on-site assessments. Over the same period, second-stage cases filed numbered 89,901, while 90,937 were processed — a figure that includes cases carried over from the previous year.

Among processed cases, follow-up phone consultations were the most common, accounting for 70,124 cases, or 77.1 percent. In-person consultations numbered 16,602 (18.3 percent), while combined in-person consultations and noise measurements accounted for 4,211 cases (4.6 percent). Noise measurements are conducted at the request of affected households when conflicts persist even after an in-person consultation.

Incidents in which inter-floor noise disputes spill over into serious violence against neighbors continue to surface with troubling regularity.

In May, a man in his 20s stabbed and killed a resident in his 50s in the elevator of an apartment building in Seo-gu, Daegu. The man, indicted on murder charges, told police he acted out of frustration over inter-floor noise from the unit above his.

In Cheonan, South Chungcheong Province, a man in his 40s who killed a neighbor in his 70s living upstairs with a bladed weapon in December last year — claiming to have been a victim of inter-floor noise — was sentenced to 25 years in prison at his first trial in July. In November 2021, a man in his 40s attacked three members of a family living below him with a bladed weapon at a villa in Namdong-gu, Incheon, amid a dispute over inter-floor noise. The incident drew criticism after police officers who responded left the scene before the situation was resolved.

The government has gradually tightened construction-stage regulations to reduce inter-floor noise in newly built apartment complexes. The centerpiece is a post-completion verification system that applies to complexes that filed for project approval on or after Aug. 4, 2022. Under the system, floor impact sound is measured in a randomly selected sample of units — 2 percent of the total — at the completion and occupancy inspection stage to verify compliance with a 49-decibel standard. The system covers newly built residential complexes of 30 or more units and, unlike the previous approach of reviewing only blueprints and laboratory test results, requires inspection of the actual finished building.

The problem is that even when a unit fails to meet the standard, authorities can only recommend that the contractor carry out remedial work or pay compensation — there is no mechanism to compel compliance. In response, the Ministry of Land, Infrastructure and Transport put forward a plan in December 2023 that would make remedial work mandatory until the standard is met, and would bar local governments from granting completion approval — effectively blocking move-ins — for noncompliant buildings. Under the proposal, construction companies would bear the cost of delay compensation and loan interest arising from postponed move-ins; the inspection sample would also be expanded from 2 percent to 5 percent, and inspections would be moved up to between eight and 15 months before completion.

The government's fifth comprehensive noise and vibration management plan, covering this year through 2030, also includes stronger management of floor impact sound in newly built residential complexes. The plan envisions holding project developers more strictly accountable for substandard results through remedial construction requirements, compensation obligations and public disclosure of inspection outcomes.

Implementing these measures would require an amendment to the Housing Act, and without such a revision the proposals carry no legal force.

"The Ministry of Land, Infrastructure and Transport and relevant agencies must strengthen follow-up management to verify whether complaints are actually resolved after they are filed, while swiftly bolstering measures to build higher-quality housing with better noise insulation and establishing an effective on-site mediation and response system," Hwang said.