Good knowledge of spatial data applications leads to successful business organizations. In the event of natural disasters such as earthquakes, interoperability between different organizations is necessary for fast and efficient action of different stakeholders. There were many occurrences of discrepancies amongst appraisers’ damage evaluations after the 1998 and 2004 Bovec municipality earthquakes, which consequently led to additional work in data processing. In such cases, building a coordinated data warehouse can greatly assist solving these problems. Implementing a data warehouse is made possible by the ETL process, which extracts, transforms and loads data. The basic functions of the spatial ETL tool are exchanging information in the geographical information system (GIS) between different users, and the ability to transparently use the given data. A newly made data warehouse also provides users an overview of the chronological developments for each building, and offers land planners the basis for the design of municipal spatial plans. In this thesis, a unification of non-homogenous data warehouses, collected from various institutions with the ETL process, is accomplished. To achieve this, the spatial ETL tool FME Desktop is used in ArcGIS, which allows entry of different data formats into the software environment and contains a rich collection of converters that enable the transformation of data and their delivery to the final data warehouse. The applicability of the newly made data warehouse concerning the 2004 Bovec earthquake is then examined. ArcGIS analytical tools are used to assess the impact and effect geological basis have on the damage done buildings. An inquiry trough descriptive and locational attributes and an analysis of the suitability of soil for construction are made. The flexibility of the spatial ETL tool is demonstrated in this study, which also turns out to be a strong tool for editing and analyzing spatial data. The effect the geological basis has on the amount of the estimated damage is, in view of the data regarding the damage to buildings and in respect of other factors (such as the year of construction and building materials used) taken into account only for the aforementioned earthquake, therefore, confirmed with relatively low reliability.