Fire Suppression System Design

Q: How much does it cost to install sprinklers throughout a building?

The cost of a sprinkler system includes the design, equipment, installation and water supply – a reservoir with a pump station often costs as much as all the pipework and sprinklers combined. Equipment and installation costs depend on the area, system type and storage height. The design includes a specification that allows several contractors to submit comparable bids, so you can find out the total cost through a tender.

Q: When is a fire suppression system mandatory?

A fire suppression system is mandatory in buildings listed in the Rules for the Design and Installation of Fixed Fire Suppression Systems, based on their use, area, height and fire load. These most commonly include warehouses and manufacturing buildings above a certain floor area, shopping centres, high-rise buildings and underground car parks. We can tell you whether your facility requires a system during an initial consultation.

Q: If one sprinkler activates, does water come out of all of them?

No. Each sprinkler has its own heat-sensitive element and activates only when the temperature around it exceeds a set threshold – usually, one or several sprinklers above the fire activate. All sprinklers activate at once only in deluge systems, which are designed specifically for flammable liquid warehouses and aircraft hangars.

Q: Can a server room be protected with water?

We don’t recommend it. For server rooms, archives and electrical switchrooms, we design gas suppression systems that leave no residue and do not damage equipment. Gas systems require a sealed room, pressure relief vents and evacuation of personnel before discharge. We include these measures in the design, together with the fire alarm control sequences.

Q: Do sprinkler systems need a separate water tank?

It depends on the pressure and flow rate of the municipal water supply. If they meet the hydraulic calculations, the system can connect directly to the network; for warehouses and factories, however, this is usually insufficient, so we design a reservoir and pump station. We calculate the reservoir capacity based on the system’s application rate and the required operating duration, and its location should be planned early, either on the site or in the building.

When a fire suppression system and its design are required

A fire suppression system is mandatory in buildings specified by fire safety regulations according to their use, area and fire load – most commonly warehouses, manufacturing buildings, shopping centres, high-rise buildings and underground car parks. A design is required for every facility where a system is installed, modified or extended; without one, the contractor cannot install the system or obtain approval for the building. The most common situations in which clients contact us are:

You’re designing a warehouse or factory that exceeds the fire compartment size limit without suppression.
You’re building a logistics centre with high-bay racking that requires in-rack sprinklers.
You’re building a server room, archive or electrical switchroom where water is unsuitable and gas suppression is needed.
The insurance company requires sprinklers, even though they are not required by regulations.
You’re changing the use of your building, and the existing system no longer meets the new fire load requirements.
Want to increase the fire compartment size or reduce the fire resistance rating of the structures? The fire suppression system then serves as a compensatory measure.

Fixed fire suppression system: what the design includes

A fixed fire suppression system is designed as a separate section of the building design, coordinated with the fire safety, water supply, electrical and fire alarm sections. The design specifies the suppression method, calculates the required amount of water or suppression agent, and defines how the system is activated and controlled. The design section includes:

explanatory report: protected areas, fire hazard class, and justification for the choice of extinguishing agent;
selection of the system type and application rate based on the materials being protected, storage height and storage method;
hydraulic calculations: sprinkler layout, pipe diameters, required pressure and flow rate;
water supply solutions – mains water, a reservoir, a pump station, and calculations for their capacity and output;
for gas and aerosol systems – room-tightness requirements, suppression agent concentration and pressure relief vents;
activation and control sequences, and interfaces with the fire detection system and smoke control;
an equipment specification you can use to select a contractor through a tender.

We design the alarm system that activates suppression at the same time – fire detection and alarm systems are prepared as an integrated part of the design.

Automatic fire suppression systems: types and where each is suitable

An automatic fire suppression system is selected based on what might catch fire and what needs protection: water suits most spaces but can damage electronics and archives, while gas and aerosol suppress fires without leaving residue but require sealed rooms. The main types are:

Sprinkler system Suppression agent – water. Used in warehouses, manufacturing facilities, retail buildings, offices and apartment buildings. Requires a water supply and pump station; not suitable for electronics.
Water mist system Extinguishing agent – finely atomised water. Used in hotels, heritage buildings and cable tunnels. It requires less water, but the equipment is more expensive.
Gas suppression system Extinguishing agent – inert or chemical gases. Used in server rooms, archives and electrical switchrooms. The room must be sealed, and people must evacuate before activation.
Aerosol system Suppression agent – fire suppression aerosol. Used in small technical rooms and cabinets. For enclosed spaces only; cleaning is required after activation.
Foam system Suppression agent – water with foam concentrate. Used at petrol stations, aircraft hangars and flammable liquid warehouses. Requires specialist equipment and foam concentrate reserves.

A single building often needs several types: sprinklers in the warehouse and gas suppression in the server room. We justify the system type in the design with calculations and standards, not a manufacturer’s proposal.

Sprinkler systems: how they work and what types are available

A sprinkler fire suppression system is the most common type of fixed fire suppression: individual sprinklers activate when the temperature at a specific sprinkler exceeds a set threshold, suppressing the fire only in that area. Unlike in the movies, all sprinklers do not activate at once – this helps limit water damage.

Sprinkler system types we design:

Wet system Pipes are permanently filled with water; the simplest and least expensive option, suitable for heated spaces.
Dry system Pipes are filled with compressed air; water enters the pipes when a sprinkler operates. Suitable for unheated warehouses and canopies.
Pre-action system Water is released only after a signal from the fire detection system; suitable for archives and spaces where accidental discharge must be avoided.
Deluge system All sprinklers are open, and the system activates across the entire zone; used for flammable liquid storage and aircraft hangars.
In-rack system Sprinklers are installed at rack levels; for high-bay logistics warehouses where ceiling sprinklers cannot reach the fire.

An automatic sprinkler system is designed based on the classification of the goods being protected and the storage height – these determine sprinkler density, water application rate and reservoir capacity. Changing a warehouse’s use, for example, by storing plastic goods instead of metal, can make the existing system inadequate.

How fire suppression system design works

Fire suppression system design takes six stages, from gathering initial information to handing over the approved design section, and takes longer than fire alarm design because of the hydraulic calculations and water supply solutions involved. The earlier we get involved, the easier it is to plan space for a pump station and reservoir, which often cannot be accommodated later in the building.

Initial information. We receive the architectural plans, a list of the materials to be protected, the storage method and height, and information about the water supply pressure and flow rate. We provide a proposal with a fixed price and timeline.
System selection. We determine the fire hazard class, select a suppression method for each group of rooms, and agree on it with the client and insurer, if they have additional requirements.
Hydraulic calculations and water supply. We calculate sprinkler layouts, pipe diameters, pump capacity and reservoir volume; we coordinate the pump station location with the architect and structural engineer.
Design. We prepare plans, diagrams, specifications and an interface matrix covering the fire alarm, smoke control and electrical systems.
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 installation supervision. We deliver the design section in PDF and DWG formats, advise the contractor during installation, and take part in testing and commissioning.

Want to know which type of system is right for your property and how long the design will take? Email the architectural plans and a list of the materials to be protected to idprojektas@idprojektas.lt or call +370 686 78507 – we’ll provide a proposal with a fixed price and timeline.

Fire suppression system design cost

The fire suppression system design is quoted as a fixed price and will not change unless the project scope changes. The price includes hydraulic calculations, plans, diagrams, specifications, revisions to address expert review comments and coordination with PAGD.

The price depends on:

protected area, number of rooms and storage height;
system type – a wet sprinkler system is the simplest, while gas and in-rack systems require more calculations;
water supply: whether the mains supply is sufficient or a reservoir and pump station need to be designed;
number of different systems in one building;
design stage – technical design, detailed design, or both;
insurer requirements, where these are stricter than regulatory requirements.

How long it takes and what you get

We specify the schedule in our proposal: we can prepare the sprinkler system design for a small facility sooner, while a logistics or manufacturing building with a reservoir and pump station takes longer. The schedule starts once we receive the architectural design; the time needed for expert review and approvals is quoted separately.

The result is an approved design section with hydraulic calculations and a specification that enables contractors to submit comparable bids. The schedule also depends on you: if the list of materials to be protected or the rack height changes, the calculations have to be revised.

Codes and standards we follow

Fixed suppression systems are designed in accordance with the Rules for the Design and Installation of Fixed Fire Suppression Systems, approved by order of the Director of the Fire and Rescue Department, and European standards: LST EN 12845 for sprinkler systems and LST EN 15004 for gas suppression systems. These documents specify which buildings require suppression, the water application rate and operating duration for each hazard class, how sprinklers must be positioned, and the requirements for the water supply. We also apply:

Fire safety design solutions – fire compartment boundaries and compensatory measures determine whether suppression is mandatory;
Insurance company requirements – international insurers’ warehouse requirements are often stricter than Lithuanian regulations;
Water supply and wastewater design standards – for the water source and pump station;
Manufacturers’ technical requirements – when the client has already selected the equipment.

When a suppression system is suitable and when we recommend another solution

Fixed fire suppression is the most expensive type of fire protection system, so it is not always the best option. If a system is not mandatory and the client wants to reduce risk, it is often cheaper to divide the building into smaller fire compartments or increase the fire resistance rating of the structures. We assess these options in the fire safety design before recommending sprinklers.

There are cases where the reverse applies. If you want a larger fire compartment, a longer evacuation route or lighter structures, a suppression system can serve as a compensatory measure, justified by risk assessment and calculations. We don’t recommend sprinklers for server rooms or archives – gas suppression is suitable there, while aerosol generators are sufficient for small technical rooms. If the building doesn’t yet have an alarm system, we start with its design, as it activates gas and pre-action systems.

Why commission a fire suppression system design from ID projektas

We design the suppression system alongside the fire safety section, so it complements rather than duplicates other measures – you won’t pay for a system where a fire wall is sufficient. The design is prepared and signed by certified specialists; their certifications are listed on the team page.

Edita Dulko – Head of Fire Safety Design, 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.
Independent designers – we prepare the design as independent consultants, not equipment suppliers, so the specification lets you select a contractor through a tender.

How much does it cost to install sprinklers throughout a building?

When is a fire suppression system mandatory?

If one sprinkler activates, does water come out of all of them?

Can a server room be protected with water?

Do sprinkler systems need a separate water tank?

Order a fire suppression system design

Send the architectural design and a description of the materials to be protected to idprojektas@idprojektas.lt, call +370 686 78507 or +370 630 08858. We’ll provide a proposal with a fixed price and schedule, and arrange a meeting in Vilnius or at your site through the contact page.

Designing the fire suppression system alongside the fire safety design at the design proposal stage makes it possible to plan space for a reservoir and pump station. This delivers the greatest savings, as there is often nowhere to install them later.

Fixed fire suppression system design