On 14 July 2025, addendum 3 to NBN S21-100–1 was published and is therefore applicable to all projects started after this date (date of the tender document).
An important change in addendum 3 of NBN S21-100–1 concerns the removal of all provisions relating to sirens connected to fire detection and fire alarm systems.
The regulations relating to the use of sirens in a fire detection project have been included in the new NBN S21-112 series of standards.
NBN 21-112–1 contains the criteria and methodology for determining the most suitable solution for alarm signalling inside and around buildings.
NBN 21-112–2 specifies the qualifications and necessary competencies for performing the following tasks :
- Preparation of the risk analysis and evaluation of requirements
- Preparation of the detailed study
- Installing the system
- Commissioning the system
- Checking, using, reviewing and maintaining the system
The third part of NBN S21-112 describes the technical criteria that alarm systems with acoustic signal generators inside and around buildings must meet.
At a later stage (date not yet known), a fourth part on Voice Alarm Systems (VAS) will be published. Until further notice, the existing NBN S21-111 series of standards will remain in force for VAS.
Important information
According to NBN 21-112–3, the standard evacuation signal for acoustic signal generators must meet specific requirements. These requirements are in line with what is commonly known as the “Slow-Whoop” signal.
Other signals are only permitted if there is a risk of confusion with other signals or for the sake of recognisability of certain signals that are already known, and provided there is a clear justification based on the risk analysis.
For any further questions, please contact your commercial representative within our organisation.