The EU Biodiversity Strategy for 2030 anticipates the development of an EU-wide methodology to map, assess and achieve good condition of ecosystems. The Joint Research Centre (European Commission) has led the development of such methodology, making use of the System of Environmental Economic Accounting - Ecosystem Accounting (SEEA EA) of United Nations as reference framework. Specifically, the EU-wide methodology follows the rules of the SEEA-EA ecosystem condition accounts, presenting useful insights to operationalise this framework for all ecosystem types in the EU. The EU-methodology provides a comprehensive set of condition variables per ecosystem type as well as recommendations on methods for setting reference levels and thresholds to determine good ecosystem condition. In this presentation, we introduce the EU-wide methodology, its relationship with the SEEA-EA, and the challenges identified during the development of this work. Regarding challenges, the presentation will introduce those that could be mitigated through further advances in Earth Observation data. The case of urban ecosystems will be used to illustrate the challenges in a practical form, to facilitate their comprehension by a broad audience. To conclude, the presentation will open a discussion on the role of Earth Observation for the mapping and assessment of good ecosystem condition, and which should be the next steps.