What are the limit values for environmental factors (noise, environment, health) when purchasing a home?

Noise protection: When quiet becomes measurable

Noise is the most frequent source of conflict and the number one health hazard in residential areas. The limit values for environmental factors related to noise are regulated in the Federal Noise Protection Ordinance (LSV). These regulations differentiate strictly according to the type of zone in which your house is located.

Sensitivity levels (ES)

To apply the limit values for environmental factors related to noise, you need to know the sensitivity level of your property:

• ES II: Residential zones and zones for public buildings (high protection requirements).
• ES III: Mixed-use zones (residential and commercial).

The decibel limits

The limit values for environmental factors differentiate between planning values (for new buildings/new noise sources) and immission limit values (for existing situations).

• Daytime: In purely residential zones (ES II), the immission limit is 60 dB(A) . If this is exceeded, the noise is considered harmful. The stricter planning limit is 55 dB(A) .
• At night: Here, the limits for environmental factors are stricter to protect sleep. In residential areas, the upper limit is 50 dB(A) , and the planning value is even 45 dB(A) .

If a property exceeds these environmental noise limits , structural measures (such as noise-reducing windows) often need to be implemented. Therefore, it is essential to check the road noise register for your canton. A house that consistently exceeds the environmental noise limits will lose value and living comfort.

Radon: The danger from the subsurface

While noise comes from outside, radon lurks in the ground. It is a naturally occurring, radioactive noble gas that is colorless and odorless. After smoking, it is considered the second leading cause of lung cancer. Here, too, there are clear limits for environmental factors .

The reference value

300 becquerels per cubic meter ( Bq /m³) applies to living spaces in Switzerland .

• The meaning: If the concentration in your potential hobby room or living room exceeds this level, action is required.
• The test: Environmental limit values for radon are often exceeded in older houses with leaky foundations. A look at the radon map of the Federal Office of Public Health (FOPH) will show you whether your dream house is located in a risk area.
• Consequence: If the environmental limit values are exceeded, you will have to carry out renovations (e.g., sealing the basement, installing ventilation). You should factor these costs into your budget before purchasing.

Electrosmog: Non-ionizing radiation (NIR)

Mobile phone antennas, high-voltage power lines, and railway power lines generate electromagnetic fields. Discussions about this are often emotionally charged, but the Ordinance on Protection against Non-Ionizing Radiation (NISV) sets objective limits for environmental factors .

The precautionary principle

Switzerland has very strict limits for environmental factors in international comparison for so-called "places with sensitive use" (OMEN), which include residential areas and children's playgrounds.

• Installation limits: These are approximately ten times lower than international recommendations in order to rule out long-term effects . For mobile phone antennas, these environmental limit values range between 4 and 6 volts per meter (V/m) , depending on the frequency .
• The reality: If you buy a house right next to a high-voltage power line or with a view of a transmission tower, you should have measurements taken to ensure that environmental limits are being met. Even if the limits are often met, the psychological impact ("electrosmog anxiety") often lowers a property's resale value more than the physical reality.

Air quality and pollutants

The air we breathe is also subject to regulations. The Clean Air Ordinance (LRV) defines the limit values for environmental pollutants such as particulate matter (PM10) and nitrogen dioxide (NO2).

• Location check: Properties on busy main roads often exceed the limit values for nitrogen oxides.
• Particulate matter: Especially in valley locations with inversion weather patterns in winter, the limit values for environmental factors can be temporarily exceeded. This is less of a legal obstacle to purchasing, but a relevant factor for asthmatics or families with small children.

Contaminated soil: Historical sins

Although not a direct emission value, the pollution of the soil from previous use (landfills, industry) is closely linked to the limit values .

• The register: If a limit value for pollutants in the soil is exceeded, the property ends up in the register of contaminated sites ( KbS ).
• The risk: A plot of land that exceeds the limit values for environmental factors affecting soil (e.g., heavy metals) often cannot be built upon without the excavated material being disposed of expensively as hazardous waste. In this case, the limit values for environmental factors directly translate into a financial risk.

How to check the limit values for environmental factors

Don't rely on statements like "It's quiet here".

• Noise register: Each canton maintains maps showing where the limit values for environmental factors for road and railway noise are exceeded.
• Radon map: The BAG provides a map showing the probability of exceeding the limit values.
• Location map for transmitter sites: The Federal Office of Communications (BAKOM) shows all antenna locations.
• On-site measurement: If you are unsure (e.g., about radon or electromagnetic radiation), a professional measurement before purchase is recommended. This is the only way to know if the environmental limits are being met.

Conclusion

The question "What are the limits for environmental factors?" leads directly to the heart of quality of life. Noise, radon, and radiation are invisible, but their effects on health and finances are real. Adhering to the limits for environmental factors guarantees that your home remains a place of relaxation and doesn't make you sick.

A house that exceeds the environmental limits for noise protection might be cheaper, but the price is your sleep. A property with radon levels exceeding the environmental limits is a health risk until you invest. Use the available cadastral maps and records. Be wary of "bargains" on main roads or in low-lying areas. Those who proactively consider environmental limits in their purchasing decisions are making a sustainable investment in quality of life and property value.

If you want to quickly check whether your desired address is affected by aircraft noise or how high the radon risk in the municipality is assessed according to the limit values for environmental factors , Loft offers comprehensive location analyses and data for your safety.

Glossary

• Environmental limit values: Legally defined maximum values for exposures (noise, radiation, pollutants) that must not be exceeded in order to protect health.
• Immission limit value (ILV): The value for noise, above which the noise pollution is considered harmful or annoying. A central concept in limit values for environmental factors .
• Sensitivity level (SLE): A zoning (e.g. residential zone = SLE II) that determines how strict the limit values for environmental factors are for noise at a particular location.
• Becquerel ( Bq ): Unit of measurement for radioactive activity (decays per second). Relevant for limit values for environmental factors related to radon (reference value 300 Bq /m³).
• Installation limit value: A strict precautionary value in the NISV (electrosmog), which is significantly below the international limit values for environmental factors in locations with sensitive uses (apartments) .