The building codes in Austria are specified by the governments of 9 federal states. These building codes are subsequently referring to guidelines of the Austrian Institute of construction engineering (OIB guidelines).

The OIB Guidelines serve to harmonise the construction engineering regulations in Austria. The federal states may declare OIB Guidelines as binding in their building codes- in fact- all federal states did so by now.

The OIB Guidelines are organised according to basic requirements for construction works of the EU Construction Products Directive.

The OIB Guidelines are designed and handled as prescriptive fire safety design rules, but it is also possible to use performance based approaches. This means that the guidelines are designed as prescriptive fire safety design rules, which should be followed to show the applicability and approvability of a fire safety design to the local building authorities. But in any case, it is possible to deviate from the prescriptive rules, if it is demonstrated by comprehensible and conclusive arguments that the required level of safety is achieved. The required level of safety is derived from comparison with a solution, which follows the OIB guidelines.
The possibility to deviate from prescriptive rules is intended to ensure the necessary flexibility for innovative architectural and technical solutions.

In the current scheme, the contractor submits a complete building design to the local building authorities. The building design includes drawings, descriptions and possibly calculations.
For special purpose buildings (e.g. hospitals) or buildings which are planned in such a way that there are significant deviations from the prescriptive fire safety codes, the fire safety design must be documented in a fire strategy document. Typically, such a fire safety design document includes drawings illustrating the location of all fire safety measures.
Based on the provided documents, the local building authorities can approve the design and give the building permission, if necessary with remarks on conditions that must be changed or added.

Austria has adopted the EU harmonized system for classification of resistance to fire and reaction to fire. A list of adopted product standards for CE marking is given in the Austrian “building products catalogue ÖE”:

https://www.oib.or.at/de/node/202261

A second building material list (ÖA) serves to establish usage regulations for construction products for which no harmonised technical specifications exist and which therefore cannot bear the CE mark.

https://www.oib.or.at/de/kennzeichnung-und-zulassung-von-bauprodukten/baustofflisten/baustoffliste-%C3%B6

Note that a CE mark is not considered as an approval for the use of a given product in a specific application. It is just a declaration of selected properties described in the product standard.

OIB-Richtlinie 2 (Ausgabe 2019)
https://www.oib.or.at/de/oib-richtlinien