Summary

The Federal Council is opening a consultation on simplifying the Federal Inventory of Protected Townscapes (ISOS). The planned amendments to the ISOS Ordinance and Spatial Planning Ordinance are intended to accelerate planning and construction procedures without excessively endangering townscape protection. The measures address the increasing housing demand and the requirements of the energy transition through clarified direct application rules and expanded discretion for cantons and municipalities.

Persons

Topics

  • Townscape protection and spatial planning
  • Housing construction and densification
  • Energy transition and solar installations
  • Federal regulation

Clarus Lead

The Federal Council is simplifying the application of the ISOS inventory through ordinance amendments to accelerate housing construction and energy transition projects. The direct application of ISOS is being restricted for densification projects and solar installations, eliminating time-consuming interest-balancing procedures. For decision-makers in cantons and municipalities, this means significant procedural simplifications and improved legal certainty. The consultation runs until May 18, 2026 and is based on findings from a round table held in 2025.

Detailed Summary

The ISOS records Swiss localities with high historical, urban planning, and architectural value and is intended to enable quality-oriented inward settlement development. Previously, cantons and municipalities had to apply the inventory directly for federal tasks, which led to time-intensive procedures. The revision clarifies the application rules and deliberately restricts direct application: For densification projects and solar installations, cantons and municipalities can now deviate more strongly within the framework of an interest-balancing process.

This differentiation significantly reduces qualified interest-balancing procedures. At the same time, the discretionary scope of cantons and municipalities is clearly defined, and the preservation objectives required by ISOS are clarified. These regulatory adjustments are intended to substantially facilitate planning and approval procedures and improve legal certainty—without disproportionately restricting townscape protection.

Key Messages

  • Federal Council opens consultation on simplifying ISOS application until May 18, 2026
  • Direct application of ISOS is restricted for densification and solar installations
  • Discretionary scope for cantons and municipalities is clarified
  • Objective: Accelerate housing construction and energy transition projects without disproportionate restrictions on protection
  • Measures are based on findings from a round table held in 2025

Critical Questions

  1. Data Quality: On what empirical data is the assumption based that restricting ISOS direct application actually leads to measurable procedural acceleration? Are there before-and-after analyses of similar regulations?

  2. Conflicts of Interest: To what extent were environmental and heritage conservation associations adequately represented at the 2025 round table, or did the construction industry dominate the discussion?

  3. Causality: Is procedural delay actually caused by ISOS direct application, or do other factors (financing, skilled labor shortage, cantonal processes) play a larger role?

  4. Implementation Risks: How is it ensured that interest-balancing in cantons and municipalities actually leads to townscape-compatible solutions when direct application is eliminated? What control mechanisms exist?

  5. Side Effects: Is there a risk that simplification will lead to erosion of townscape protection, particularly in financially weak municipalities with less technical expertise?

  6. Solar Installation Exception: Why are solar installations blanket-exempted from ISOS direct application? Are there distinctions based on size or visibility?

Source Directory

Primary Source: Federal Council opens consultation on simplifying ISOS application – https://www.news.admin.ch/de/newnsb/WUlXOaxnDPwSZ9kNNXssW

Verification Status: ✓ February 11, 2026

This text was created with the support of an AI model. Editorial Responsibility: clarus.news | Fact-checking: February 11, 2026