Build days are fun! And offer a number of benefits and opportunities to individuals and the community. They enable rapid and collaborative problem solving, assembly of complex projects with great speed, and educational opportunities for all involved. =Challenges= * Communicating enough about how to build with Replimat in both distilled and time-release forms * Holding a safe space for experimentation and mistakes * Getting everyone's hands and minds on. =Approaches= * Projectors cycling through inspiring build photos * Short presentation of Replimat construction fundamentals * Lots of parts * Lots of tools * A goal, competition, or build inspiration =References=