Design of fire extinguishing systems

Installing an automatic fire extinguishing system in a building can be mandatory or optional. It can be a condition for a building permit, forced by legislation or based on the requirements of authorities. The insurance company can also make the automatic fire extinguishing system a condition of the insurance. 

The automatic extinguishing system ensures that the conditions set for fire safety are met. The condition set by the building control for obtaining a building permit means that the building or certain of its premises must be equipped with automatic fire extinguishing system in order for the building permit to be granted. When applying for a permit, the rescue authority can order the installation of fire extinguishing system based on the activity in the building or fire loads, or if the building’s evacuation safety cannot be made to meet the requirements. The required extinguishing equipment must be standardized or approved on the basis of equipment-specific type approval.

The building’s safety analysis report also often requires an automatic fire extinguishing system. In many cases, Decree 848/2017 of the Finnish Ministry of the Environment stipulates the use of an automatic fire extinguishing system. For example, it’s always required for a P2 class wooden building with more than two floors, as well as for a P1 class building if its height exceeds 56 meters. The fire safety requirements are also met if the building is designed and built based on the “assumed fire development“, which computationally simulates fire events likely to occur in the building during its life cycle.

Fire extinguishing system planning in different stages of the project

The best result is achieved when an fire extinguishing system designer and a fire safety engineer are attached to the project already in the project planning phase:

Project planning

  • the fire hazard classification is evaluated depending on the building’s occupancy and use
  • a site-specific comparison of fire extinguishing systems is carried out, taking into account, among other things, the water supply and other details affecting the implementation design
  • a suitable system is selected
  • evaluation of cost savings; the best benefit is achieved when the fire extinguishing system design is combined with the fire safety design

Implementation planning

  • system dimensioning and fire extinguishing system design
  • produce construction drawings

Construction phase

  • changes during installation and official approvals for changes if necessary
  • supervising during installation.

Possibility of cost savings during the construction phase

The use of automatic fire extinguishing system may be justified, even if Degree 848/2017 of the Finnish Ministry of the Environment does not even require it. The use of automatic fire extinguishing system is often worthwhile, as they can be used to realize a much more fire-safe building, and in addition, the examination of extinguishing systems with tools of performance-based fire safety design often produces cost savings. Performance-based fire safety design also implements sustainable development throughout the building’s life cycle and reduces the carbon footprint of construction.

With automatic fire extinguishing system, structures and building materials are not subjected to the same fire stress in a fire as without an extinguishing system, so mitigations can often be implemented. The installation of the fire extinguishing systems can affect, among other things, the class requirements of load-bearing structures, the size of fire compartments based on the purpose of use, the fire compartmentalizing building parts, the lengths of passageways and the number of exits.

Practical applications can be mentioned, for example, reducing the amount of structural steel used in load-bearing steel structures based on a lower temperature in fire. At the same time, the fire protection of steel structures can be reduced or completely omitted. The need for fire dampers and fire insulation of ventilation ducts can also be minimized; it may even be possible to dispense with fire and smoke control dampers. The amount of smoke need to be removed is significantly lower due to the lower temperature of the smoke reservoir. Ventilation ducts can be used for smoke clearance to a considered extent.

The reductions are reflected in the total costs, as the lighter structures are often also cheaper. Many insurance companies also offer discounts on building’s insurance premiums if it’s equipped with automatic extinguishing system.

Contact us, and we’ll discuss your project’s fire extinguishing system solutions and your possibilities for cost savings!

Supervising during installation

If necessary, you can also get supervision of the installation of the fire extinguishing system from us. With careful supervision, it is possible to avoid mistakes related to the implementation of plans, and to ensure that the construction runs smoothly according to the schedule. Errors made in the installation of the fire extinguishing system are difficult to detect afterwards. In the worst possible scenario, errors are revealed in a fire situation.

Supervising also avoids unnecessary additional costs, such as the dismantling and rebuilding of incorrect implementations detected in inspections required by the authorities.

More information

More information about automatic fire extinguishing systems and how to choose them on our website: