Building in Noise-Exposed Areas

Building in Noise-Exposed Areas

Silence is a precious commodity. It contributes to people’s health and well-being and plays a key role in making a location attractive for work, living, and leisure.

At the same time, urban development in Switzerland is increasingly moving toward denser, higher-rise construction, while the population and traffic volumes continue to grow. This results in conflicting goals between noise protection requirements and spatial planning guidelines for increased urban density.

As the owner of infrastructure, the authorities are obligated to ensure effective noise protection.

The legal deadline for retrofitting main roads and other roads expired in March 2018. Nevertheless, numerous cantons and municipalities remain in default.

Roads that have not been retrofitted can lead to significant restrictions on building use. Under previous law, new buildings with noise-sensitive rooms could generally only be approved if noise emission limits were met. In some noise-polluted areas, this led to de facto construction bans or forced developers to implement comprehensive noise protection measures at their own expense or to wait for the existing infrastructure to be upgraded. Exemptions were only possible under strict conditions and required that all reasonable structural and design measures had been exhausted.

Against this backdrop, the Federal Assembly adopted a revision of the Environmental Protection Act (EPA) and the Noise Abatement Ordinance (NAO), which entered into force on April 1, 2026.

Background of the Revision

In the building permit process, noise emission limits must generally be complied with in noise-sensitive rooms (art. 22 para. 1 EPA and art. 31 para. 1 NAO). The decisive factor here is the noise exposure at the center of open windows (art. 39 para. 1 NAO).

In practice, the so-called “ventilation window practice” had become established in some cantons, whereby compliance with the limits was required at only one window per room. In 2016, the Federal Supreme Court declared this practice inadmissible and required compliance with the limit values at all windows of noise-sensitive rooms. This strict legal ruling led to significant restrictions on construction activity in noise-polluted areas and was a major catalyst for the legislative revision that has now taken place.

New Approval Procedures in Noise-Affected Areas

As of April 1, 2026, new, legally regulated options exist for approving construction projects even if the noise exposure limits cannot be fully met. The prerequisite is that at least one of the following alternatives is met for each residential unit (art. 22 para. 2 lit. a EPA):

  • Controlled residential ventilation combined with either a cooling system or at least one noise-sensitive room in which the noise exposure limits are met at a window.
  • At least half of the noise-sensitive rooms have a window where the noise exposure limits are met.
  • At least one noise-sensitive room has a window that complies with noise exposure limits, and in addition, a private outdoor space (e.g., balcony or terrace) is available where the limits are met.

In all cases, appropriate enhanced structural minimum protection against external and internal noise must also be ensured.

Adjustments to Planning Law

Simplifications have also been introduced in the area of land-use planning. Building zones may now be designated or adjusted even if planning values or noise exposure limits cannot be met, provided that the following conditions are cumulatively met (art. 24 para. 3 EPA and Art. 29 NAO):

  • There is an overriding interest in inward urban development.
  • Sufficient, easily accessible recreational areas are located nearby.
  • Binding measures are established to ensure an appropriate acoustic quality of living.

Classification and Practical Implications

The revision represents a paradigm shift: While noise protection has tended to take precedence in the past, there will now be a greater need to balance it with spatial planning interests. This opens up new opportunities for building owners, developers, and investors to realize projects also in noise-polluted areas.

At the same time, the requirements remain demanding. In particular, the selection and combination of suitable structural, technical, and design measures continue to gain importance. Furthermore, it is likely that the concrete application of the new provisions will only be clarified through the practice of enforcement authorities and courts.

We support local authorities in analyzing and implementing the new noise protection regulations (e.g., in the permitting process) and advise building owners and investors on the planning and execution of their projects in noise-polluted areas.