Web-based geographic information systems (GIS) and planning support systems are widely adopted as digital tools to support planning practices. The respective solutions tend to be isolated implementations aimed at a single planning purpose due to the specific requirement concerning their data, methodology, involved stakeholders, etc. With data platforms, GIS infrastructures, and the possibility to use web-based software that relies on open standards, creating a planning support infrastructure is more feasible than ever. Such infrastructures can create opportunities for governments to draw on existing systems and create the potential to improve planning practices through enhanced information and analysis. This paper describes the development of the cockpit social infrastructure, a planning application that serves as an interface between Hamburg's urban data platform and the municipal planners of social infrastructure. Its unique institutional setting as well as its reliance on an open standard software architecture make it a unique case for potential planning support infrastructure.