The development of a European Spatial Data Infrastructure within the INSPIRE initiative requires data providers to make their data available in a homogeneous data schema in order to simplify the exchange and use of data between different authorities. The conversion of the original data into another schema – in this case an INSPIRE data schema – is called schema transformation. Such functionality can be offered in an SDI by means of Schema Transformation Network Services. Currently several potential architectures of such transformation services have been proposed for the INSPIRE implementation. A Transformation Service can be seen as specific type of Processing Service, which has the source data, transformation rules, source and target schemata as inputs and the target data as output. This paper analyses and evaluates the use of a Web Geoprocessing Service in combination with the less common GearScape Geoprocessing Language (GGL) for service based schema transformations.