Introduction
Since July 2025, new versions of the Belgian standards for fire detection and alarm systems have come into effect. These changes primarily impact standard NBN S 21-100-1 and the NBN S 21-112-* series. They directly affect the practices of installers, designers, operators, and fire safety managers. In this context, ANPI provides a comprehensive breakdown of these changes to better understand the technical and organizational implications and prepare effectively for their implementation (via our webinar replay that you can purchase on our e-shop).
Towards a new normative architecture
Until 2025, the NBN S 21-100-* series covered all requirements related to fire detection and alarm systems. However, technological advancements, the need for clarification, and the necessity to harmonize standards with international practices have led to a logical split between automatic fire detection and alarming.
Thus, the NBN S 21-100-* series now focuses exclusively on automatic fire detection, while the NBN S 21-112-* series governs all alarm devices, including audible and voice alarms. This separation allows for clearer interpretation, better specialization of requirements, and more flexible adaptation to the specificities of different devices.
Overview of the standards concerned
Here are the standards that will be applicable as of July 17, 2025:
- NBN S 21-100-1:2025: This standard concerns automatic fire detection, detailing the rules applicable to risk analysis, design, installation, commissioning, use, control, verification, and maintenance of systems.
- NBN S 21-112-1:2025: This standard concerns the selection criteria for alarm systems, based on a structured needs assessment.
- NBN S 21-112-2:2025: This standard concerns the qualifications and competencies related to alarm systems.
- NBN S 21-112-3:2025: This standard defines the rules for audible alarm devices such as sirens.
Upcoming: NBN S 21-112-4 will cover the requirements for voice alarm systems (expected in 2026 or 2027).
NBN S 21-100-1:2025 – Major developments
NBN S 21-100-1:2025 introduces several notable changes aimed at facilitating the application of technical requirements while incorporating recent advancements. These include:
- A new terminology for surveillance levels (e.g., "partial surveillance" becomes "compartment surveillance").
- An exhaustive documentary annex (Annex I), which summarizes the documents required at each project phase, facilitating monitoring and controls.
- The official integration of Video Fire Detection (VFD), with recognition of three types of detection (smoke, flame, and combined technologies).
- Two design methods for VFD: a simplified one, compliant with prescriptions, and a performance-based one, based on software demonstrations.
- A simplification of requirements for small installations, particularly through a streamlined risk analysis procedure.
A structured overview for small installations
Small fire detection projects now benefit from reduced administrative burden. This simplification applies to risk analysis and the documentation to be provided. The goal is to avoid an overload of formalities while maintaining an optimal level of safety.
These provisions are particularly aimed at buildings with low occupancy or limited risks, allowing for a more proportionate application of technical regulations.
NBN S 21-112-1:2025 – Selection based on risk analysis
This standard marks a major step forward in formalizing the selection of alarm systems. It is based on a standardized questionnaire (Annex A.4) to structure risk analysis and assess actual needs, as well as guidance for expected responses. The objective is to provide a simple, understandable, and adaptable framework for all types of buildings.
NBN S 21-112-2:2025 – Qualifications and competence management
Competence management is a crucial pillar for the compliance of fire safety systems. This standard specifies the required profiles and qualifications according to roles: designers, installers, inspection bodies, verifiers, and managers. It builds upon the foundations established in NBN S 21-100-2, adapting them to the context of alarm systems. It also provides a solid basis for the training and certification of professionals in the sector.
NBN S 21-112-3:2025 – Technical specifications for audible devices
Audible alarm devices, such as sirens, are now regulated by a dedicated standard. This specifies technical requirements for wiring, power supply, sound level, and evacuation signal. The standard evacuation signal is the "slow whoop," but alternatives can be considered with justification based on risk analysis.
Strict limits are set for the sound level:
- Minimum level: 65 dB(A)
- Maximum level: 105 dB(A)
- 75 dB(A) for waking sleeping individuals.
The permissible loss in case of a single fault is also regulated, with two possible calculation methods: one based on the building's configuration (compartment, level, area), the other on the sound pressure level.
Consequences for BOSEC certified installers
Installers already certified under previous versions of the standards will not have to restart their entire process. Existing BOSEC certificates will be automatically adjusted, subject to the necessary accreditation deadlines. Voice alarm systems, however, remain certifiable based on the NBN S 21-111-* series until the NBN S 21-112-4 comes into force.
Summary and recommendations
The standard revisions provide a concrete response to expressed needs on the ground: greater clarity, flexibility, and adaptability in the face of technological developments. They also strengthen the safety culture by increasing the accountability of stakeholders.
ANPI recommends that companies, design offices, and installers:
- Quickly obtain the full texts of the standards. The standards are available on the Bureau de Normalisation website.
- Update their internal procedures, taking into account the new documentary requirements.
- Organize information or training sessions for their technical teams. Do not hesitate to contact us for your training needs.
- Conduct an internal compliance audit to anticipate adaptation points.
- Contact ANPI for any questions or support needs.
Contact
To learn more or to receive personalized support, you can contact us via info@anpi.be.
