In "A Framework for K-12 Science Education," researchers call for teachers to make dramatic shifts in practice -- and sustain in these changes in practice -- so students can engage in rigorous and equitable three-dimensional science learning. Project-Based Learning (PBL) motivates students from diverse backgrounds to persist in learning. This project presents design features that bring together the assets of the Framework with PBL, and then tests these features to derive design principles that serve as commitments for designing for teacher change and student learning. Close ethnographic study of 10 teachers over 5 years in a design-based research study is triangulated with data collected across 41 districts in multiple states engaged in a PBL elementary science curriculum. The following design principles provide guidance for developing materials that support the depth necessary for promoting changes to teachers' practice at scale: Adaptive, Responsive, and both Enjoyable and Intellectually Satisfying.