In this NSF-funded project, we investigate whether and how participating in three-dimensional architectural design and modeling via a simulation game-based learning platform will support integrated math representation and active problem solving for middle school students. Using a design-based research approach, an architectural, simulation game-based mathematics learning platform (called “E-Rebuild”) is developed and implemented. The extended E-Rebuild will frame mathematical representation and problem solving as a structured series of architectural design and problem solving actions; allow for end-user customization of the platform via parameter-based level generation; and incorporate unobtrusive diagnostic assessment as well as assessment-driven, adaptive learner support during the course of game play.