Noise in apartments: limits, rights and what to check before moving in
Around one million people in Switzerland are exposed to road noise that exceeds the legal limit. What the decibel scale means, which limits apply — and what you can legally demand as a renter or buyer.
Immission limit · Road noise · Residential zone day
At night 45 dB(A) — around 1 million people in Switzerland exceed this value
Noise is the most underestimated housing factor. Unlike a small kitchen or a missing storage room, it is nearly impossible to fix after the fact — and its impact on sleep quality, stress hormones and long-term cardiovascular health is documented by dozens of studies. In Switzerland, roughly one million people are exposed to road noise that exceeds the legal immission limit. Anyone wanting to know whether that applies to a specific apartment or municipality now has access to data that was once hard to find.
How Switzerland measures noise: dB(A) and the logarithmic scale
Noise is measured in decibels dB(A) — the A-weighting, which models the human ear's sensitivity. The scale is logarithmic: every doubling of sound pressure adds +6 dB; perceived loudness doubles at +10 dB. In practice this means: the difference between 55 and 65 dB is not "10 units more" — it is the gap between a speaking voice (55 dB) and a busy open-plan office (65 dB).
Loudness reference: typical sound levels
| Sound level | Comparison | Residential relevance |
|---|---|---|
| 30 dB(A) | Silent bedroom, quiet night | Ideal for sleep |
| 40 dB(A) | Quiet conversation, library | Good; WHO night limit (outdoors) |
| 45 dB(A) | Quiet road, occasional car | LSV night limit SL II (residential zone) |
| 55 dB(A) | Normal conversation, busy office | LSV day limit SL II (residential zone) |
| 60 dB(A) | Vacuum cleaner 2 metres away | LSV limit mixed zone (SL III) |
| 65–70 dB(A) | Busy city street | Above limit; sleep disturbance likely |
| 75+ dB(A) | Motorway 10 metres away | Significant health hazard |
The legal system: sensitivity levels and limits
The Noise Abatement Ordinance (LSV, SR 814.41) defines four sensitivity levels (SL), assigned to the land-use zones in the local zoning plan. The more sensitive the zone, the lower the permitted noise level. For most rental apartments, SL II (residential and mixed zone with residential component) is decisive:
Immission limits (IGW) for road noise by sensitivity level (LSV Annex 3)
| Sensitivity Level | Use | Day limit | Night limit |
|---|---|---|---|
| SL I | Recreation zones, hospitals | 50 dB(A) | 40 dB(A) |
| SL II | Pure residential zones | 55 dB(A) | 45 dB(A) |
| SL III | Mixed zones (residential + commercial) | 60 dB(A) | 50 dB(A) |
| SL IV | Industrial and commercial zones | 65 dB(A) | 55 dB(A) |
For rail noise, different (sometimes slightly higher) limits apply under LSV Annex 4; for aviation noise, Annex 5. Important: limits apply at the loudest window of the apartment when open — not inside the room behind a closed acoustic window.
The three biggest noise sources in Switzerland
People exposed above the immission limit (SL II) · Switzerland
Road noise dominates by far. It affects urban main roads, cantonal roads and motorways — the latter are shielded by noise barriers, but those barriers end somewhere. Rail noise is often underestimated at night: a freight train produces peak levels of 75–85 dB, several times an hour on busy lines. Aviation noise primarily affects the catchment areas of the national airports in Zurich, Geneva and Basel.
What noise does to health
The WHO Environmental Noise Guidelines for the European Region (2018) summarise the evidence: road noise above 53 dB(A) at night (outdoors) raises the risk of cardiovascular disease in a statistically significant way. From as little as 40 dB(A) at night, sleep stages are fragmented without the sleeper waking up. Chronic noise exposure raises cortisol and adrenaline levels, affecting blood pressure and heart rate over time. Children in noisy homes show poorer reading performance and higher stress hormones in studies.
What you can check before moving in
- Homematch municipality page: shows the noise exposure index broken down by road, rail and air noise — for a first regional picture.
- Cantonal noise registers: most cantons (ZH, BE, AG, etc.) maintain publicly accessible digital noise maps with actual assessment levels for every road.
- Measure yourself: smartphone apps (e.g. NIOSH SLM, Decibel X) measure sound levels on site. Measure at peak traffic time during the day and around 11 pm at night.
- Visit at the right time: see the apartment once in the evening and once early in the morning — that reveals the true noise level.
- Clarify which side faces the street: road-facing vs. courtyard-facing can differ by 15–20 dB in a noisy street.
- Check rail lines: karte.sbb.ch shows freight and passenger rail routes. Freight trains run more frequently at night; check the timetable.
Legal situation: when do you have claims?
Swiss tenancy law protects renters from excessive noise in two ways:
- Defect in the rental property (CO Art. 258/259a): if the apartment is not fit for its contractual purpose due to noise — e.g. because a new road was built or the landlord concealed the noise load — a defect exists. The tenant can give notice of the defect and claim a rent reduction.
- Neighbour noise (CC Art. 684): excessive interference from neighbours — music, commercial activity, construction — is unlawful. The municipality and cantonal police can intervene; the landlord is obliged to act against third parties (CO Art. 259).
Noise when buying: what applies to sellers?
When buying property, the purchase warranty (CO Art. 197 ff.) applies: if the seller conceals a significant noise load they knew about, it may constitute fraudulent misrepresentation. Particularly relevant: future infrastructure projects (new road, tram line, flight path change) the seller might be aware of. Have the purchase contract explicitly confirm that the seller is not aware of any planned noise-generating projects in the immediate vicinity.
Acoustic windows: solution or sticking plaster?
Acoustic windows dampen outside noise by typically 30–40 dB — from 70 dB outside to 30–40 dB inside. That sounds like a lot, but there is a decisive catch: the window must stay closed. Anyone wanting to ventilate in summer or sleep with the window open in a heatwave is exposed to the full outdoor noise. Acoustic windows do not solve the noise problem — they mask it when closed. The LSV limit applies at the open window: apartments that only fall under the limit with the window shut are considered excessively noisy.
Frequently asked
- How loud may it be in my apartment (residential zone)?
- In a pure residential zone (Sensitivity Level II), the immission limit is 55 dB(A) during the day (6–22 h) and 45 dB(A) at night (22–6 h) for road noise, measured at the open window of the loudest room. Above these levels, authorities can require remediation measures.
- How do I find out whether my apartment is above the limit?
- On Homematch you can see the noise exposure index for your municipality. For the specific property: cantonal noise maps (e.g. gis.zh.ch for Zurich, geodata.vd.ch for Vaud) show calculated road noise levels down to building level. A direct measurement with a calibrated sound level meter is the most precise method.
- What happens if the limit is exceeded?
- For existing installations (roads, rail lines), the owners are required to take remediation measures (noise barriers, road surfaces, traffic restrictions) or — where that is not possible — fit affected buildings with acoustic windows. The costs are borne by the party responsible for the noise (federal government/canton for national roads/rail, municipality for local roads).
- Can I demand noise protection measures as a renter?
- You can demand from your landlord that the apartment is fit for its contractual use. Whether the landlord must proactively install acoustic windows depends on the individual case. Where noise is demonstrably excessive (above the limit) and was not known at the time of signing, the conciliation authority is the right first step.
- Is rail noise more harmful than road noise?
- At the same assessment level, the annoyance effect is similar, but the character differs: rail noise comes in short, very loud bursts (train pass-bys up to 85 dB(A)), while road noise is a constant background hum. Impulse noise wakes sleeping people more often. Freight traffic on Swiss main lines is particularly intensive at night.