Legislation & Regulations
The legislative and standards framework underpinning every Voxiss installation. From British Standards specific to voice alarm and fire detection, to European product standards and UK statutory duty, our designs are engineered to meet the relevant requirement for each project.
2025
Martyn's Law
Terrorism (Protection of Premises) Act 2025
Martyn’s Law is a UK Act of Parliament introduced in response to the recommendations of the public inquiry into the 2017 Manchester Arena attack. Named in memory of Martyn Hett, one of the 22 victims, the Act places legal duties on those responsible for publicly accessible premises and events to reduce vulnerability to, and the risk of harm from, terrorist attacks.
<strong>Capacity 200–799.</strong> Responsible persons must consider procedures that could be expected to reduce the risk of physical harm if an attack were to occur at, or near, the premises — including evacuation, invacuation, lockdown and communication procedures.
<strong>Capacity 800+.</strong> All standard tier duties, plus a requirement to put in place public protection measures, monitor and maintain those measures, and document the assessment in a Security Plan submitted to the regulator (the Security Industry Authority).
Standard Tier
Capacity 200–799. Responsible persons must consider procedures that could be expected to reduce the risk of physical harm if an attack were to occur at, or near, the premises — including evacuation, invacuation, lockdown and communication procedures.
Standard Tier
Capacity 200–799. Responsible persons must consider procedures that could be expected to reduce the risk of physical harm if an attack were to occur at, or near, the premises — including evacuation, invacuation, lockdown and communication procedures.
Premises in Scope
Qualifying premises and events include: shops, restaurants, bars and nightclubs; entertainment venues, theatres and cinemas; sports grounds and stadia; hotels and visitor attractions; places of worship and museums; healthcare and education premises; transport hubs; and qualifying public events.
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Martyn’s Law elevates the role of clear, intelligible emergency communication. Where a public-address system is the means by which staff and visitors are directed during an incident, that system becomes part of the premises’ protective security posture. Voxiss design considerations driven by the Act:
- System architecture supporting all four response modes — invacuate, evacuate, lockdown, communicate — not just fire evacuation.
- Pre-recorded message libraries beyond the standard fire-alarm message set, covering the broader threat landscape.
- Operator paging stations with zoned and all-call broadcast capability for live incident management.
- Resilience and redundancy in line with the standby and integrity requirements of EN 54-4 and EN 54-16, where the system has dual fire / non-fire purpose.
- Integration with security and access-control systems where the venue’s Security Plan calls for combined response.
Implementation timeline: The Act received Royal Assent in 2025, with an implementation period of approximately 24 months before duties become enforceable. The Security Industry Authority (SIA) is the appointed regulator. Voxiss is engaging with clients now to ensure new and existing PA / VA installations support the operational procedures the Act requires.
-16
EN 54-16
Voice Alarm Control and Indicating Equipment (VACIE)
EN 54-16 is the harmonised European product standard governing voice alarm control and indicating equipment — the central rack of equipment from which fire-purpose voice messages are stored, generated, supervised and broadcast. It defines the requirements, test methods and performance criteria that a VACIE must meet to be placed on the market within the UK and EU.
Mandatory for CE / UKCA Marking
EN 54-16 is one of the harmonised product standards under the Construction Products Regulation (CPR). Any voice alarm control panel sold for use as part of a fire detection and alarm system in the UK or EU must hold valid EN 54-16 third-party certification — without which it cannot lawfully be CE or UKCA marked, and cannot be specified for life-safety use under BS 5839-8.
Functions Defined by the Standard
Mandatory Functions
Reception of fire signals from the FACIE; automatic generation of the voice alarm condition; indication of the voice alarm condition; output to loudspeakers in clearly defined zones; manual silencing and reset; integrity monitoring of the audio path including amplifiers and loudspeaker lines.
Optional with Requirements
Manual override (paging) microphone; phased evacuation; redundant power amplifier with automatic transfer; emergency microphone with priority; multiple message storage; audio input from sources other than fire (subject to override); fault output to remote indicating equipment.
Integrity Monitoring
The standard requires continuous supervision of the entire audio chain — including loudspeaker circuits — with any short-circuit, open-circuit or earth fault detected and indicated within 100 seconds. A single fault must not prevent the system from broadcasting voice alarm to any zone. This drives the use of A/B-leg loudspeaker wiring, end-of-line monitoring and redundant amplifier topologies on every Voxiss VA design.
Voxiss Specification Policy
All voice alarm control equipment specified by Voxiss for fire-purpose use carries valid EN 54-16 third-party certification from a recognised notified body, with the Declaration of Performance (DoP) held on file as part of the project handover documentation.
-4
EN 54-4
Power Supply Equipment for Fire Detection & Fire Alarm Systems
EN 54-4 is the harmonised European product standard for the power supply equipment that energises fire detection, fire alarm and voice alarm systems. It defines the requirements for the primary mains supply and the secondary (battery) supply, the charging arrangement, fault monitoring, and the conditions under which the system must continue to operate when normal power is lost.
Why It Matters for Voice Alarm
A voice alarm system cannot perform its life-safety function unless it remains powered during an incident — including incidents in which mains supply is interrupted by the event itself. EN 54-4 ensures that the entire VA chain (control equipment, amplifiers, loudspeaker circuits) has a certified standby power source sized to the duration required by the relevant code of practice (typically 24 hours quiescent followed by 30 minutes alarm under BS 5839-1 / -8).
Core Requirements
- Two independent supplies: primary (mains) and secondary (battery), each capable of supplying the maximum alarm load on its own.
- Automatic transfer: on loss of mains, the secondary supply must take over without interruption to fire / VA function.
- Charger performance: the secondary supply must be recharged to 80% of capacity within 24 hours of mains restoration.
- Fault monitoring: continuous supervision of mains presence, battery condition, charger health and battery isolation — with any fault indicated locally and (where required) at remote indicating equipment.
- Battery integrity: deep-discharge protection, periodic load testing, end-of-life prediction.
Standby Capacity Calculation
The required battery capacity is determined by:
Capacity (Ah) = (Iq × Tq) + (Ia × Ta) + safety margin
Where Iq is the quiescent current, Tq the quiescent duration (typically 24 h), Ia the alarm current, and Ta the alarm duration (typically 0.5 h). Voxiss documents the full calculation for every project as part of the design submission, with battery sizing confirmed against the system’s actual measured load on commissioning.
5839-8
2023
BS 5839-8:2023
Power Supply Equipment for Fire Detection & Fire Alarm Systems
BS 5839-8 is the principal British Standard code of practice for voice alarm systems used in fire applications in the United Kingdom. It is referenced by Approved Document B of the Building Regulations and by the great majority of UK fire-strategy specifications. BS 5839-8 sits within the wider BS 5839 suite (Part 1 covers fire detection and alarm; Part 6, dwellings; Part 9, emergency voice communication, etc).
The 2023 edition is the current revision, replacing BS 5839-8:2013. It aligns the British code with current EN 54 product standards (notably EN 54-16 and EN 54-24), updates guidance on networked / IP-based architectures, refines speech intelligibility methodology, and tightens requirements around integrated PA / VA installations.
Key Subject Areas
Zoning, message structure, integration with the fire detection system, emergency microphone provision, phased evacuation strategy, redundancy and fault tolerance, integration with PA where dual-purpose.
Specifies the Speech Transmission Index (STI) or Common Intelligibility Scale (CIS) target across the listening area — typically STI ≥ 0.50 / CIS ≥ 0.70 in the majority of locations.
Cable types and segregation, loudspeaker mounting, system testing, intelligibility measurement, documentation, certification at handover.
Routine attention by site staff, periodic inspection and servicing by competent persons, log-book recommendations, recommended frequency of preventive testing.
Relationship with EN 54
BS 5839-8 is a code of practice (the “how”); EN 54 is a product standard set (the “what”). The two work in tandem: BS 5839-8 specifies that VA control equipment shall be EN 54-16 certified, that loudspeakers shall be EN 54-24 certified for fire purpose, and that power supply equipment shall be EN 54-4 certified.
50849
2017
European Standard
BS EN 50849:2017
Sound Systems for Emergency Purposes
BS EN 50849 is the European standard governing sound systems used for emergency purposes other than those that are part of, or directly triggered by, a fire detection and alarm system. It covers the design, installation and commissioning of sound systems intended to assist the controlled movement of people during emergencies of all types — including security incidents, terrorist threats, severe weather, public-order events and other non-fire scenarios.
It superseded the earlier IEC 60849, modernising the technical framework and aligning sound-system performance requirements with current EN 54 component standards while remaining distinct in its non-fire scope.
Where It Applies
EN 50849 is the appropriate reference standard where the primary purpose of a sound system is broader than fire alone — or where a fire system needs to be supplemented by an additional emergency-purpose system. Typical scenarios:
- Premises subject to Martyn’s Law obligations where the response model includes invacuation, lockdown or controlled relocation in response to non-fire threats.
- Stadia, transport hubs and large public venues where general public-safety messaging is required outside of any fire condition.
- Sites where BS 7827 (sports venues) or local-authority licensing conditions require a documented emergency sound system.
- All-hazards emergency planning where the system supports a broader range of incident types than fire detection alone.
Relationship with BS 5839-8
Fire-purpose voice alarm. Triggered by, or interfaced to, a fire detection system. Mandatory under most UK fire strategies for buildings of meaningful occupancy.
Non-fire emergency sound. Triggered manually or by other security / safety systems. Increasingly required alongside, or independently of, BS 5839-8 for venues with all-hazards exposure.
Many modern installations are dual-purpose: a single sound system designed to satisfy both BS 5839-8 (when the source is fire) and BS EN 50849 (when the source is something else). In this case, fire signals always take priority, and the relevant performance requirements of both standards apply.
Performance Requirements
EN 50849 mirrors many of the performance requirements of BS 5839-8 — speech intelligibility (STI / CIS), sound pressure levels, fault monitoring, redundancy and standby power — while allowing greater flexibility in system architecture where the use case is non-fire. Voxiss designs treat both standards in parallel from the outset, ensuring that the resulting installation can fulfil whichever role is required at any given moment.