This document discusses building a business case and policy to support a 10-year research data management roadmap at an institution. It provides examples of roadmaps from other universities that were informed by funder policies. It also summarizes the development of a roadmap, business model, and policy at the University of Southampton, including engaging stakeholders, surveying researchers, and estimating storage needs and costs over 10 years. Roadmaps are useful for engaging senior leadership and researchers to understand current practices and align them with policy.