The expansion of broadband infrastructure is a key driver of economic and social development. However, current planning and approval processes are fragmented, time-intensive, and inefficient due to the involvement of multiple stakeholders, heterogeneous data formats, and varying regulatory requirements. Different modeling approaches (2D plans, 3D models, GIS, and documents) lack standardized integration, leading to inconsistencies and delays, particularly in planning and approval. The absence of a structured digital workflow further complicates coordination and slows decision-making. A core challenge is the lack of automated validation. Regulatory and technical compliance must be manually checked, making the process error-prone and inconsistent. This extends project timelines and increases the administrative burden, especially for approving authorities. This paper proposes a structured approach to optimize broadband planning and approvals through a Building Information Modeling (BIM)-based workflow. By integrating 3D models with Geographic Information System (GIS) data and regulatory rules, we present a standardized method that supports authorities in streamlining approvals and offers planners a clear framework for execution. Automated compliance checks reduce manual work, minimize errors, and increase transparency. Applying this workflow to broadband deployment in Germany shows clear benefits. A real-world case study indicates reduced approval times, automated model checks, and more efficient decisions. This structured, scalable process offers a concrete solution for accelerating broadband expansion effectively and transparently.