We present an algorithmic framework for a multi-robot modular assembly system. Motivated by the prospects of in-space assembly, we focus on the NASA Automated Reconfigurable Mission Adaptive Digital Assembly Systems (AR-MADAS) framework, in which multiple types of robots work together in a team to build large structures. Unlike with other multi-robot construction systems, the geometry of structures that ARMADAS robots can build is not limited to the class of histogram shapes. To address the intractability of path planning for a robot system with the exponentially growing number of dimensions, we present a decoupled planning approach, where the assembly and path planning is performed iteratively by one robot team at a time. We present a number of data structures which help us avoid collisions and deadlocks in the resulting robot schedule.