This is Building Journal, a builder's sketchbook and progression guidance system. This is a mod that introduces a useful system for creating and trying out building quests, with verification and reward systems to encourage players to build, and build creatively within limits.
The Building Journal gives you commissions; a challenge that gives you a list of conditions for your own build to follow, and introduces the Builder's Compass and Drafting Table, allowing you to mark down your builds no matter how crazy or cool, and validate them with your commissions.
The Building Journal is designed to allow for custom commissions. Anyone can create their own commissions using the handy README and add them to their own singleplayer worlds or servers.