To achieve the goals of the European Green Deal, the EU has introduced an action plan for financing sustainable growth. The Sustainable Finance Disclosure Regulation (SFDR) simplifies investments in sustainable projects by establishing clear criteria to assess their contribution to climate goals. This is based on the Taxonomy Regulation, which is central to the European Sustainable Finance Action Plan (SFAP). Companies must prove that their investments are genuinely sustainable. For building operators, this regulation presents additional regulatory challenges. Transparency obligations and sustainability standards apply not only to the acquisition and ownership of new buildings but also to the renovation of existing buildings and specific modernization measures. While the Taxonomy Regulation currently lacks binding requirements and does not specify how many compliant buildings a fund must contain to be considered sustainable, the timeline for implementing these regulations and reporting obligations is tight and may introduce further changes in the coming years.