The article describes the system architecture concept applied in the REMSSBOT project, focusing especially on the use of the Catalogue of Data Sources (CDS). The design approach is explained, taking into account the existing situation and the general requirements for environmental information in the REMSSBOT participating regions. The REMSSBOT metainformation system is presented, together with a description of the EEA ETC/CDS and Thesaurus, on which the REMSSBOT CDS datamodel was based. The functionality of the CDS is also shown, as well as the search and navigation approach. Last, the standards and components used for the implementation of the system architecture are given, together with a short description of the implementation, design and process itself. The design of the system architecture of the REMSSBOT-system was a general task within the REMSSBOT project: to design one system architecture for three computer systems with different frontand back-ends in the Attica, Piemonte and the Scheldt region.