A Technical Overview
UNI 11988:2025 is an Italian national standard issued by UNI (Ente Italiano di Normazione). It defines the technical and operational requirements for Emergency Voice Alarm Communication (EVAC) systems interfaced with fire detection and fire alarm systems. Published in 2025, the standard provides a comprehensive framework to help ensure effective voice-based emergency communication in buildings.
Purpose and context
Traditional audible alarms (sirens or bells) may not provide sufficient guidance during emergencies, especially in complex buildings or crowded environments. UNI 11988:2025 addresses this gap by regulating systems that deliver clear, intelligible spoken messages to occupants – supporting faster, more orderly evacuations and reducing panic. The standard reflects modern fire-safety engineering principles and aligns with performance-based safety approaches.
Scope
The standard applies to newly designed and installed EVAC systems integrated with fixed fire detection systems. It covers the full lifecycle of these systems, including:
- System design and acoustic planning
- Installation and system integration
- Commissioning and functional testing
- Operation, inspection, and maintenance
Simple acoustic warning devices without voice functionality are explicitly excluded.
Key technical principles
UNI 11988:2025 places strong emphasis on speech intelligibility, system reliability, redundancy, and power-supply continuity during emergencies. It sets criteria for loudspeaker placement, zoning, message prioritization, and coordination with fire detection logic. Verification and testing procedures help ensure that system performance remains consistent over time.
Acoustic verification: what is measured on site
To confirm that voice messages are delivered effectively, verification activities typically include measuring sound pressure level (SPL) of EVAC messages at representative points, STIPA and RT60 inside acoustic areas (ADA) background noise levels (including building services when relevant), and checking the signal-to-noise margin that affects message clarity. Where needed, octave/third-octave band analysis helps identify frequency-related issues and supports corrective actions (e.g., loudspeaker tuning, zoning or placement adjustments). Test results should be recorded and reported to ensure repeatability over time and to support commissioning and periodic checks.
Applicability and value
Although voluntary in nature, UNI 11988:2025 represents recognized best practice in Italian fire-safety design. It is intended for fire-safety engineers, system designers, installers, building owners, and authorities having jurisdiction. Adoption of the standard supports regulatory alignment, enhances occupant safety, and improves emergency response effectiveness.
Conclusion
UNI 11988:2025 marks a significant step toward safer, more intelligible emergency communication in buildings. By standardizing EVAC system design, verification, and management, it contributes to higher levels of fire safety and more controlled, effective evacuations.
To support implementation of the new standard, Senseca’s XPT800 Class 1 sound level meter helps professionals verify EVAC acoustic performance through accurate measurements of message SPL and background noise, enabling consistent reporting and documentation of results in line with UNI 11988:2025.
