Are there categories 1 to 4 for fire detection systems in Belgium?
No, this breakdown into numbered categories has no legal or normative basis in Belgium. The classification into categories (often noted A to E) belongs to the French fire safety systems framework and does not apply to Belgian buildings. In Belgium, the design of fire detection installations is based on the NBN S21-100-1 standard, which does not work with fixed categories but through an analysis of the specific needs of each building: area, occupancy, activity, risk. This confusion often arises among managers who have consulted French resources. The Belgian reasoning is different in its logic, even if the final objective—adapting the level of protection to the actual risk—remains the same. It is therefore necessary to start from the correct documentary basis to properly size an installation.
How does NBN S21-100-1 determine the type of detection to be installed?
NBN S21-100-1 sets the design and installation rules for fire detection systems based on a risk analysis specific to the building, not on a grid of pre-established categories. The criteria taken into account include the nature of the occupancy (offices, industry, healthcare facility, collective housing), the area and configuration of the premises, the presence of persons with reduced mobility or dependent persons, and the specific risks related to the activity carried out. This analysis determines whether detection must cover the entire building or only certain risk areas, what type of detectors is suitable (smoke, heat, flame, multi-criteria), and how to organize the control panel and detection zones. The design office or installer then translates this analysis into an installation plan compliant with the standard, which will be verified during the acceptance of the installation.
What is the link with the classification of low-rise, medium-rise and high-rise buildings?
The Royal Decree of 7 July 1994 establishing basic standards for fire and explosion prevention classifies buildings into three categories according to their height: low-rise, medium-rise and high-rise buildings. This classification directly conditions the requirements for compartmentation, evacuation and smoke extraction, and therefore indirectly the extent of detection to be provided. A medium-rise or high-rise building generally imposes reinforced requirements in terms of generalized detection and smoke extraction, due to longer evacuation times and increased difficulties for emergency services intervention. This height-based classification does not replace the risk analysis of NBN S21-100-1, it is added as a basic regulatory constraint. The two texts combine to define the required level of protection.
Generalized detection or partial detection: what practical difference?
Generalized detection covers all rooms of a building with automatic detectors, while partial detection (or localized) only protects certain areas deemed at risk, such as technical rooms, archives or professional kitchens. The choice between the two depends on the risk analysis conducted according to NBN S21-100-1: a healthcare facility or a high-rise apartment building will tend towards generalized detection, while a small workshop with a localized risk may be satisfied with targeted protection. This choice has direct consequences on the number of detectors, the sizing of the control panel and the number of zones to be wired. Poorly positioned partial detection leaves blind spots that delay the detection of a fire outbreak, especially at night, when the majority of victims are affected by smoke before even waking up.
What practical consequences on equipment and wiring?
The level of protection adopted directly determines the type of control panel, the number of detection loops and the characteristics of the wiring to be installed. An installation extended to an entire medium-rise or high-rise building requires a control panel capable of managing several distinct zones, a backup power supply guaranteeing operation in the event of a power cut, and connections whose fire behaviour is adapted to the function provided (alarm transmission, smoke extraction control). The equipment installed must be BOSEC certified to guarantee its compliance with Belgian requirements. The more the risk analysis reveals significant issues (many people present, difficulty of evacuation, risky activity), the closer the system sizing approaches a complete architecture, with redundancy and connection monitoring, rather than a simple local control panel serving a few detectors.
Who decides the level of protection to be installed in a given building?
The choice of the level of protection results from a risk analysis conducted upstream, generally by a specialized design office or the installer in collaboration with the operator's prevention advisor. This analysis is based on the building classification according to the Royal Decree of 7 July 1994, on the requirements of NBN S21-100-1, and on the provisions of the Code on Well-being at Work (Book III, Title 3) relating to fire prevention in the workplace. The territorially competent emergency zone (hulpverleningszone) may also be consulted for advice, particularly during a permit application or a significant modification of the building. It also carries out the inspections that validate, or not, the compliance of the installation carried out.
How to choose the right level of protection for one's own building?
The right level of protection is determined by combining three elements: the building classification (low-rise, medium-rise or high-rise according to the Royal Decree of 7 July 1994), the nature of the occupancy and the public accommodated, and the specific risks related to the activity carried out. A healthcare facility or an apartment building accommodating dependent persons justifies a higher level of protection than a rarely frequented warehouse. There is no automatic grid: each building is subject to its own documented analysis, which then serves as the basis for sizing the equipment and wiring. Having this analysis carried out by a professional before any equipment purchase avoids over or under-sizing the installation, and guarantees its consistency with subsequent periodic inspection requirements according to NBN S21-100-2.