How many decibels counts as inter-floor noise — 39 by day, 34 by night, and the three-step centre process
You cannot sleep because of the footsteps upstairs, and the management office responds with "we passed on a request to be careful." Here is what most people do not know: inter-floor noise in Korea has a legally defined numerical standard. The Rules on the Scope and Standards of Inter-Floor Noise in Multi-Family Housing set out the categories of noise and the decibel limits by time of day, and whether those limits were exceeded can be established by measurement. It is a problem that can be handled with numbers rather than argument.
Inter-floor noise comes in two forms
The rules divide it in two, and which one applies determines which figures you are measured against.
- Direct impact noise — noise from running, walking and similar movement. The thumping everyone complains about.
- Airborne noise — noise from televisions, audio equipment and the like.
There is an important exclusion. Water supply and drainage sounds from bathrooms, toilets and utility rooms fall outside the definition of inter-floor noise. However maddening the sound of a toilet flushing at night, this framework cannot address it. Plumbing noise has to be approached as a building defect or a structural issue instead.
The figures — 39dB by day, 34dB by night
The time bands are daytime from 06:00 to 22:00 and night-time from 22:00 to 06:00.
- Direct impact noise, 1-minute equivalent sound level: 39dB day / 34dB night
- Direct impact noise, maximum sound level: 57dB day / 52dB night
- Airborne noise, 5-minute equivalent sound level: 45dB day / 40dB night
These reflect a 2023 tightening in which the equivalent sound level limits for direct impact noise moved from 43dB to 39dB by day and from 38dB to 34dB by night — four decibels each. If you are working from older material that says 43dB, it needs updating. The maximum sound level and airborne noise limits were left unchanged.
One condition must be read alongside the figures: the limit has to be exceeded three or more times within one hour for the noise to be recognised. A single loud thump does not put you over the line. The intent is to capture noise that is sustained and repeated.
What does 39dB actually feel like
The numbers alone convey little. An equivalent sound level converts the noise over a set period into an energy average, which is not the same as the peak. A 1-minute equivalent level of 39dB means "the same total energy as a steady 39dB tone lasting a minute." Short, sharp impacts therefore tend to be caught by the maximum sound level limits (57dB day, 52dB night), while sustained footsteps or a treadmill tend to be caught by the equivalent level. That is precisely why two separate standards exist.
The Inter-Floor Noise Neighbour Centre — the actual three steps
When the parties cannot resolve it themselves, the public channel is the Inter-Floor Noise Neighbour Centre, run by the Korea Environment Corporation at no cost to either side. The process has three stages.
- Telephone consultation — call 1661-2642 (weekdays 09:00–18:00) or apply online through the Inter-Floor Noise Neighbour Centre. Your situation is registered and you are advised on next steps.
- On-site consultation — a counsellor visits, hears both sides and proposes a way forward. A significant share of cases end here.
- Noise measurement — where consultation fails, measurement follows: continuous recording at one or more points for not less than one hour and not more than twenty-four hours.
That the measurement window can run to twenty-four hours matters in practice. If the noise only occurs at particular times, you need to describe the pattern precisely at the consultation stage so that the window covers it.
The record worth keeping before you apply
It helps to keep a noise log before contacting the centre. Nothing elaborate — date, time, duration and type of noise is enough. "12 July, around 23:40, roughly 20 minutes, running." With that in hand, the pattern is easy to explain and it gives you grounds when the measurement window is set.
Readings from a smartphone noise app are worth something as context but are not used as the basis for an official determination, because error varies widely with the device and where you hold it. Treat app readings as circumstantial notes that noise occurred at a given time, and leave the determination to formal measurement.
The management body has a legal role too
It is easy to assume the management office is powerless, but the Multi-Family Housing Management Act assigns it a real function. Where a resident reports inter-floor noise and requests action, the management body may verify the facts and recommend that the resident causing the noise stop it. Where necessary it can also consider measures available under the management rules.
So when you approach the office, rather than "it's loud, do something," it is more effective to submit a written request for fact-finding and a cessation recommendation. A written record also serves later as proof that you attempted resolution through the management body. Where a complex has an inter-floor noise management committee, that is another available route.
Noise through walls and from facilities is judged differently
Sound coming through the wall from next door — inter-unit noise — is not directly covered by the inter-floor standard, which presumes noise between units above and below. It sits in the same category of exclusion as the bathroom drainage sounds mentioned earlier.
Noise from shared facilities such as lift machine rooms, water pumps or car park barriers is likewise not inter-floor noise, and should be pursued as a facility management or environmental noise matter. In those cases the right route is to require the management body to inspect the equipment, or depending on the case, to file with the local authority's environmental department. Working out which category your problem falls into is the first step that saves a wasted trip.
Where the process stops
The centre is a mediation service, not an enforcement authority. Exceeding the limits on measurement does not by itself trigger a fine or a compulsory order. What it does deliver is an objective figure, and that changes the picture considerably if the matter later goes to environmental dispute mediation or civil proceedings. "It's noisy" and "the night-time equivalent level was exceeded three or more times within an hour" carry very different weight.
The point is that inter-floor noise is not a choice between enduring it and fighting about it. There are defined limits, there is a service that measures them at no charge, and keeping a record makes that process far quicker. The original text of the rules is available at the Korean Law Information Center.
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