The European Commission Joint Research Centre, an EU-based research institution, has published a building-level assessment of rooftop PV potential across the European Union (EU). Using the Digital Building Stock Model R2025, the study evaluates approximately 271 million buildings covering 37,370 km² of footprint area. The analysis estimates a total rooftop PV potential of 2.3 TW, including 1.822 TW from residential buildings and 519 GW from non-residential buildings. Annual electricity generation potential from rooftop PV across the EU is estimated at 2,750 TWh using current PV technology. The study finds that non-residential rooftops alone could cover planned PV deployment under the REPowerEU 2030 target. Across the member states, rooftop solar could meet more than 50% of current electricity consumption in most cases, with several countries exceeding 95%. The analysis also evaluates per-capita PV potential and alignment with 2050 decarbonization scenarios. The open-access Digital Building Stock Model R2025 dataset supports building-level energy planning, policy evaluation, and grid integration analysis across the EU.