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After the user has created a customer / project, the risks to be
considered must be selected. Four risks are available for a risk
analysis:
¨ Risk R 1 , Risk of loss of human life
¨ Risk R 2 , Risk of loss of service to the public
¨ Risk R 3 , Risk of loss of cultural heritage
¨ Risk R 4 , Risk of loss of economic value
The competent body is responsible for defining the values for
the tolerable risks. It is advisable to accept the normative val-
ues without changes.
When performing a risk analysis by means of the Risk Tool, the
actual state must be considered without selecting protection
measures. In a second step, a desired state where the existing Figure 3.3.1.1 Calculation of the collection area
risk is minimised by specific protection measures so that it is
less than the tolerable risk specified in the standard is created
by using the copy function, which can be found in the “Build-
ing” tab. This procedure should always be used. grandfathering clause does not apply. As a result, a lightning
In addition to the ground flash density and the environment of protection system on an existing building may have to be test-
the building, the collection areas for direct / indirect lightning ed for a comprehensive consideration.
strikes must be calculated in the “Building” tab. Three types of The “Zones” tab (Figure 3.3.1.2) allows the user to divide a
buildings can be used for the calculation: building into lightning protection zones and these lightning
¨ Simple structure protection zones into individual zones. These zones can be cre-
ated according to the following aspects:
¨ Building with high point
¨ Type of soil of floor
¨ Complex structure (Figure 3.3.1.1).
¨ Fireproof compartments
In case of “Building with high point”, the distance between
+/– 0.00 m ground level as well as the top edge (highest point) ¨ Spatial shields
must be defined for “Highest point”. In this case, the posi- ¨ Arrangement of internal systems
tion is irrelevant. “Complex structure” allows to simulate an ¨ Existing protection measures or protection measures to be
interconnected building structure as exact as possible and to taken
calculate its collection area. ¨ Loss values
When calculating the collection areas and when performing
risk analyses, it must be observed that only interconnected The division of the structure into zones allows the user to con-
building parts can be assessed. If a new building is added to sider the special characteristics of each part of the structure
an existing structure, it can be considered in the risk analysis when assessing the risk and to select adequate “made-to-
as a single object. In this case, the following normative require- measure” protection measures. Consequently, the total costs
ments must be met on site: of protection measures can be reduced.
In the “Supply lines” tab, all incoming and outgoing supply
¨ Both building parts are separated from each other by lines of the structure under consideration are defined. Pipes
means of a vertical fire wall with a fire resistance period do not have to be assessed if they are connected to the main
of 120 min (REI 120) or by means of equivalent protection earthing busbar of the structure. If this is not the case, the risk
measures. of incoming pipes must also be considered in the risk analysis.
¨ The structure does not provide a risk of explosion. Parameters such as
¨ Propagation of surges along common supply lines, if any, ¨ Type of line (overhead line / buried line)
is avoided by means of SPDs installed at the entry point ¨ Length of the line (outside the building)
of such lines into the structure or by means of equivalent
protection measures. ¨ Environment
If these requirements are not fulfilled, the dimensions and the ¨ Connected structure
necessary protection measures must be determined for the ¨ Type of internal cabling and
complete building complex (old and new building). Thus, the ¨ Lowest rated impulse withstand voltage

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