Land is essential for the provision of food, water and energy for many living systems, and is critical to human activity. However, in rapidly growing urban areas, access to land is restricted by the competing demands of housing, industry, commerce, infrastructure, transport, agriculture as well as the need for open spaces and green areas, and the protection of sensitive ecosystems.With on average 117.5 people per square kilometre in Europe, it is easy to see why land use planning and management is such an important environmental issue for the EU. SENSOR (http://www.sensor-ip.org/) is funded under priority area 6.3 of the Sixth Framework Programme Global change and ecosystems, and it was launched in December 2004. The aim of the project is to develop integrated, computer-based, sustainability impact assessment tools to support the European Union in assessing more accurately the longer-term impact of its policies on multifunctional and sustainable land-use. Access to reliable and harmonised data across Europe is a fundamental precondition for realisation of the SENSOR project.<br />Interoperability and open architectures are core requirements for state of the art implementations of IT solutions (Klopfer, 2006). Service oriented architectures based on a commitment to using open standards enables a system of component based building blocks, which can be chosen, run and maintained according to their best match of user requirements, independent of vendor solutions or storage models.A basic foundation for all data related work in SENSOR is the draft INSPIRE principles (INSPIRE, 2002), which by themselves build on various international standards. Standardisation bodies like ISO or CEN are developing de jure standards, whereas organisations like the Open Geospatial Consortium (OGC) develop specifications that by a consensus process and their common acceptance become de facto standards.