How is fire protection measured

Fire compartments, robust structures and fire protection clearances ensure safety

The prescribed fire protection distances are between 4 m and 10 m. Fire compartments are required in larger buildings and where there is an increased risk of fire. Structures must always withstand the fire for 30 minutes.

Fire protection distances - protection for neighboring buildings

Fire must not spread to other buildings in the event of a fire. There is therefore a minimal amount of space between neighboring buildings and systems Fire protection distance to be observed.

Prescribed fire protection distances

The required fire protection distances depend on the building materials of the outermost layers of the outer wall construction:

5 mBoth outermost layers consist of building materials of category RF1
7.5 mOne of the two outermost layers consists of combustible building materials
10 mBoth outer layers are made of combustible building materials

If the Exterior wall constructions (with the exception of doors and windows) one Fire resistance of 30 minutes the fire protection distances may be reduced:

4 mBoth outermost layers consist of building materials of category RF1
5 mOne of the two outermost layers consists of combustible building materials
6 mBoth outer layers are made of combustible building materials

If in the building dangerous substances are stored or processed, the fire protection distances must be increased.

Substitute measures if the distances are not reached

If the fire protection distances are not observed, alternative measures can be taken. Examples are a fire-resistant design of the outer walls or fire-resistant cladding and relocation of the windows and doors.

This is how fire protection distances are measured

    Structures - sufficient fire resistance ensures stability

    Structures must be stable; their expansion when heat is generated must be taken into account. Quantitative requirements are made via the Fire resistanceAre defined.

    For smaller buildings without special uses or fire hazards is usually a for supporting structures Fire resistance R 30 required. Exceptions are, for example, supporting structures in single-storey buildings, buildings with small dimensions or single-family houses: There are no requirements for fire resistance.

    Structures in basement floors must have the same fire resistance as the floors above the natural terrain. The fire resistance is at least R 60.

    Fire compartments and firewalls - so that the fire does not spread

    The following fire compartments are to be separated:

    • adjoining buildings and systems
    • Storeys above and below terrain
    • Vertical and horizontal escape routes
    • Vertical connections such as ventilation and installation shafts
    • Rooms with building services systems
    • Rooms with different uses / risk of fire
    • Areas with technical fire protection equipment
    • Areas for evacuation

    Passages and openings are fire-resistant Fire protection closures, for example, to equip doors with EI 30 fire resistance. Breakthroughs and lead-throughs for cables must also be sealed in a fire-resistant manner.

    Openings in walls or ceilings forming fire compartments are at least with the Fire resistance of 30 minutes foreclose. If lines have to be provided with a sealing or partitioning element (fire protection collar), the installation must be carried out in accordance with the test report.

    Basically applies to Sealing elements for pipelines:

    • the wall is installed on both sides
    • in the case of the ceiling, it is installed below the ceiling

    Fire resistance of fire walls

    Firewalls must be stable. The stability must be maintained even if the structure collapses on one side.

    The following requirements apply to fire walls that are prescribed by cantonal building legislation:

    • REI 180 for medium-height buildings and high-rise buildings
    • REI 90 for buildings of small height
    • REI 60 for single-family houses and ancillary buildings

    Fire protection guidelines of the VKF

    15-15 Fire protection clearances, supporting structures, fire compartments

    Enhance the supporting structure and preserve the building fabric
    See in the video how planners and engineers proceed when converting or renovating historic buildings.


    You can find more videos on fire protection during renovations under “Examples from practice”.

    Information on fire wallspdfExplanation 100-15 «Fire walls» of the VKF
    Designations REI 30, EI 30, E 30

    When assessing a component, the following criteria are decisive:

    R.Load capacity
    E.Room closure
    I.Thermal insulation
    ddFire resistance period, corresponds to the minimum time in minutes during which a component must meet the requirements placed on it

    Example: REI 30 is a component that:

    • remains stable for 30 minutes in the event of fire (R)
    • prevents the fire from spreading to neighboring rooms for 30 minutes (E)
    • keep the heat away from surrounding areas for 30 minutes (I)