Voice alarm system design
A voice alarm system broadcasts instructions telling people where and when to evacuate during a fire, instead of using sirens. UAB “ID projektas” prepares voice alarm system design sections for shopping centres, hotels, offices, production facilities and other buildings with high occupancy, throughout Lithuania.
We determine the voice alarm zones, loudspeaker layout, speech intelligibility and announcement scenarios, and coordinate the design with the review process and PAGD. Our projects are prepared by certified fire safety specialists with more than 15 years’ experience in this field.
Get a proposal with pricing and timeline
Email your project materials to idprojektas@idprojektas.lt – you’ll receive an initial response with a preliminary scope within a few business days.
Phone consultation
Call +370 686 78507 or +370 630 08858. Office: Marijampolės g. 5, Vilnius – we prepare projects throughout Lithuania.
When you need a voice alarm system instead of sirens
Voice alarm systems are needed in buildings where a simple siren is not enough: when people are unfamiliar with the building, when evacuation must take place in stages, or when different zones need different instructions at the same time. Whether a system is required for your building is determined in the fire safety section, based on the building’s purpose, occupancy and evacuation scheme. Common scenarios include:
- Shopping centres, cinemas, concert halls and sports arenas where visitors are unfamiliar with the emergency exits.
- Hotels and sanatoriums where people sleep and need to be woken by a clear announcement.
- High-rise office buildings where the fire floor and adjacent floors are evacuated first, while others wait for instructions.
- Production and logistics buildings with noisy areas that require higher sound pressure levels and more loudspeakers.
- Schools, hospitals and care facilities where staff manage evacuations based on announcements.
Voice alarm system: what the design includes
A voice alarm system is designed as a separate section of the building project, coordinated with the fire safety section and the fire detection and alarm system that activates it. What matters most is not volume but speech intelligibility: people must be able to understand the announcement from the furthest point in a room, even in noisy conditions. The design section includes:
- explanatory note: evacuation zone layout based on the evacuation scheme, and system operating logic;
- loudspeaker layout plans based on room height, acoustics and background noise, and sound pressure level calculations;
- speech intelligibility (STI) assessment in problem areas – high-ceilinged, reverberant or noisy spaces;
- announcement scenarios: which announcements are broadcast, in what order and to which zones when the alarm is activated;
- control panel location, firefighters’ manual announcement microphone, priority logic;
- cable routes with fire resistance requirements to ensure the system also operates in the fire zone;
- backup power calculations and equipment specifications for the contractor tender.
We design the fire detection and alarm system that activates the voice alarm system alongside it – ensuring that the zones and announcement scenarios match in both sections.
Evacuation schemes and emergency exits: how they determine voice alarm zones
An evacuation scheme is a drawing in the fire safety section showing emergency exits, evacuation routes and directions from each room. We use it to define the voice alarm zones.
- Zones based on evacuation stages A separate announcement can be broadcast to each zone, so zone boundaries must align with evacuation stages and fire compartments.
- Emergency exits Their number and width are determined by occupancy and evacuation route length – these are specified in the fire safety design before the voice alarm system is designed.
- Evacuation plans Plans posted in corridors are a separate operational document, prepared for a completed building in accordance with the General Fire Safety Rules.
Emergency lighting and evacuation signs
Emergency lighting – self-powered lights and illuminated exit signs that indicate the evacuation direction if the power fails – is designed in the electrical section based on the evacuation scheme.
In the fire safety section, we identify which evacuation routes and exits require lighting, then pass these requirements on to the electrical design team—so that signs, lighting and voice announcements all point people in the same direction.
How voice alarm system design works
Voice alarm system design is completed in five stages, from analysis of the evacuation plan to delivery of the approved design section. The system is designed once the fire safety section has been prepared and alarm zones are known, so we join the project at the technical design stage, when the evacuation plan has already been approved.
- Initial information. We receive the architectural section, the evacuation plan from the fire safety section, alarm zones, room uses and finish details needed for the acoustic assessment. We provide a proposal with a fixed price and deadline.
- Zoning and scenarios. We divide the building into voice alarm zones, prepare the evacuation stage logic and announcement list, and coordinate these with the client and building manager.
- Design and calculations. We lay out the speakers, calculate sound pressure and speech intelligibility, and prepare plans, diagrams and specifications.
- Expert review and approvals. We submit the design section for expert review, respond to comments and coordinate it with the Fire and Rescue Department. Revisions to address comments are included in the price.
- Handover and testing. We deliver the design section in PDF and DWG formats, advise the contractor during installation, and take part in speech intelligibility measurements and commissioning.
Would you like to know whether your building needs a voice alarm system and how long the design will take? Email the architectural design section to idprojektas@idprojektas.lt or call +370 686 78507 – we’ll provide a proposal with a fixed price and timeframe.
Voice alarm system design cost
The proposal states a fixed price for the voice alarm design, which does not change unless the project scope changes. The price includes zoning, scenarios, acoustic calculations, plans, specifications, revisions in response to review comments, and coordination with PAGD.
The price depends on:
- building area, number of floors and number of voice alarm zones;
- acoustically challenging spaces – high-ceilinged halls, atriums and noisy production areas;
- number of evacuation phases and complexity of scenarios;
- whether the fire alarm system has already been designed or both sections are being prepared together;
- project stage – technical design, detailed design, or both.
How long it takes and what you get
We specify the design section delivery time in our proposal – it depends on the building size and the number of voice alarm zones. The timeframe starts once we receive the approved evacuation scheme; review and approval times are stated separately.
The result is a coordinated design section with zoning, announcement scenarios and specifications, enabling contractors to submit comparable bids and the building manager to prepare evacuation instructions for staff. The timeframe also depends on you: if the evacuation scheme or room use changes, the zoning has to be redesigned.
Codes and standards we follow
The need for a voice alarm system is determined by the General Fire Safety Requirements and the Rules for the Design and Installation of Fire Detection and Alarm Systems. We apply the LST EN 54-16 (voice alarm control and indicating equipment), LST EN 54-24 (loudspeakers) and LST EN 50849 (sound systems for emergency purposes) standards to equipment and system operation. These documents specify which buildings require voice announcements, the sound pressure level and speech intelligibility to be achieved, how power supplies must be backed up, and how the system must respond to a component failure. We also apply:
- The evacuation scheme and evacuation stage logic from the fire safety section – these determine the zone boundaries.
- Acoustic calculation methods – for assessing speech intelligibility in reverberant spaces.
- Fire resistance requirements for cables – so announcements also reach the fire zone.
- The building manager’s operational needs – the voice alarm system can also be used for routine announcements if this is included in the design.
When are sirens enough, and when do you need voice announcements?
A siren is enough in buildings where people know the premises and evacuate at the same time – small offices, production facilities with permanent staff, and apartment buildings. If a system is not required but the client wants greater safety, improving evacuation signage and lighting is often less expensive than installing a voice alarm system – we assess this in the fire safety section.
Voice announcements are essential when evacuation takes place in stages or people are unfamiliar with the building. Phased evacuation means not everyone has to leave a high-rise building at once, helping prevent congestion in stairwells – we substantiate this solution with evacuation time calculations. If the building already has a background music system, we check whether it can be adapted for emergency use; usually it cannot, because this type of equipment does not meet standards for backup power and self-monitoring.
Why commission your voice alarm design from ID projektas
The design is prepared and signed by certified specialists whose certifications are listed on the team page.
- Three sections – one coordinated solution We design the voice alarm system together with the fire safety section and fire alarm system, so zones, announcements and evacuation stages match across all three sections – reducing the likelihood of the project being sent back from review due to inconsistencies.
- Edita Dulko Fire safety design lead, with over 15 years’ experience in design and safety assessment.
- Irina Demidova-Buizinienė Fire safety expert, PhD in materials science, certified cultural heritage specialist, member of LGSA and PDPA.
After design handover
Revisions to address expert review and FAPD comments are included in the agreed fee, provided the project scope does not change. During installation, we advise the contractor, and before handover we take part in speech intelligibility measurements. If results in a problem area fall short of the required level, we specify what needs to be changed. Changes resulting from the contractor’s proposed alternative equipment are assessed and agreed with you separately.
Frequently asked questions
When is a voice alarm system required?
Voice alarm systems are required in buildings specified by the General Fire Safety Requirements and fire alarm design rules, based on their use and occupancy – most commonly shopping centres, entertainment venues, hotels, healthcare facilities and high-rise buildings. We determine whether a system is required for your building in the fire safety section, based on its building category and evacuation scheme.
How many emergency exits does a building need?
The number of emergency exits depends on the room’s purpose, its occupancy and the evacuation route length to an exit. Most spaces with high occupancy need at least two independent exits on opposite sides. We determine the exact number and width in the fire safety section, then define the voice alarm zones based on these exits.
What’s the difference between an evacuation scheme and an evacuation plan?
An evacuation scheme is a project drawing used to design exits, signs, lighting and voice alarm systems. An evacuation plan is an operational document displayed in the corridors of a completed building, showing people where they are and how to get out. The scheme is prepared by the designer; the plan is prepared by the building manager or a company hired by them, based on the approved scheme.
Can an existing background music system be used for evacuation announcements?
Usually not, because voice alarm systems must meet strict requirements for backup power, fire-resistant cabling, self-monitoring and announcement priority, which standard music equipment does not meet. The reverse is possible: a voice alarm system can also be used for daily announcements or background music, if this is included in the design.
Order a voice alarm system design
Send the architectural design section and evacuation scheme to idprojektas@idprojektas.lt, or call +370 686 78507 or +370 630 08858. We’ll provide a proposal with a fixed price and timeframe; you can arrange a meeting in Vilnius or on site via the contact page.
A voice alarm system designed together with the fire safety section and fire alarm system is less likely to be sent back from review and enables phased evacuation – the most cost-effective route to project approval.
