What is the difference between a conventional system and an addressable system?
A conventional system divides the building into zones: each zone groups several detectors connected on the same loop, and the control panel indicates which zone is in alarm, without identifying the precise detector. An addressable system assigns each detector, each manual call point and each module a unique address on a bus, allowing the control panel to display the exact device triggering the alarm.
Both technologies must comply with standard NBN S 21-100-1 for design and installation, and undergo maintenance in accordance with NBN S 21-100-2. The choice between the two is not a matter of intrinsic quality, but of matching the building's complexity with the level of information the operator needs in case of alarm.
How does wiring differ between the two technologies?
Conventional wiring requires a separate loop per zone, which multiplies the number of cables run from the control panel to each sector of the building. The more zones there are, the denser and more expensive the wiring network becomes to install, particularly in compartmented buildings or those with multiple levels.
Addressable wiring relies on one or more closed-loop buses, to which all detectors and modules are connected in series, regardless of their number within the manufacturer's specified limits. A single bus can thus cover several floors, reducing the total cable length and simplifying routing through false ceilings and technical ducts. This architecture also facilitates compliance with the looping and fire-resistant cable requirements set out in NBN S 21-100-1.
What is the precision of fire location according to the technology?
In conventional detection, location stops at zone level: on a large office floor or an entire storey assigned to a single zone, the intervention team must search the entire sector to find the source. In addressable detection, the control panel displays the exact detector, with its room label, reducing search time before intervention.
This granularity becomes critical in buildings with complex circulation (multiple corridors, technical basements, large open-plan areas) where every minute saved before location counts for the fire service of the emergency zone (hulpverleningszone). In a small building with a simple layout, the precision difference between the two technologies has little practical impact on actual search time.
What is the impact on installation and operating costs?
At purchase, an addressable detector costs more than a conventional detector, and the addressable control panel is also more expensive per unit. This equipment gap is partly offset, in medium to large buildings, by the reduction in wiring volume and the simplification of electrical work.
In operation, addressable systems facilitate periodic inspection operations required by NBN S 21-100-2: each detector can be tested and diagnosed individually from the control panel, without having to isolate an entire zone. Conventional remains often more economical in a small building with few zones, where the additional cost of addressable is not justified by a significant operational gain.
Which technology to choose according to building size and complexity?
The choice is primarily based on the building classification established by the Royal Decree of 7 July 1994 (low, medium or high-rise buildings) and the number of detection zones required. The taller, more compartmented or more frequented the building, the more precise location becomes a safety criterion, not just an operational convenience.
| Criterion | Conventional system | Addressable system |
|---|---|---|
| Building size | Small area, few zones | Medium to high-rise building, multiple levels |
| Location | By zone | By individual detector |
| Wiring | One loop per zone | Shared closed-loop bus |
| Scalability | Limited by zone capacity | Adding detectors on existing bus |
| Equipment cost | Lower per unit | Higher per unit |
For a simple tertiary building on one or two levels, conventional often remains sufficient. For a medium or high-rise building as defined by the 1994 decree, addressable provides a real operational benefit.
Is the addressable system more scalable in case of building extension?
An addressable system expands by simply adding new detectors to the existing bus, within the capacity announced by the manufacturer, without having to run a new dedicated loop. This flexibility particularly suits tertiary buildings expected to evolve: floor reconfigurations, creation of new partitions, surface extensions.
A conventional system reaches its limits more quickly: each new zone requires an additional loop from the control panel, which may require reviewing the existing wiring architecture or installing a higher-capacity control panel. For a property manager anticipating successive works, the scalability of addressable reduces major interventions on the installation during each transformation phase. In all cases, any extension must remain compliant with NBN S 21-100-1 and undergo inspection before commissioning.