This project centers on an ethnography of a stonemasonry workshop attached to St Mary’s Cathedral in Edinburgh, Scotland. St Mary's is a nineteenth-century, neo-gothic cathedral, and one of the largest in Scotland. The workshop, which is coming at the end of a thirty-year program to repair a backlog of stone maintenance issues, trains apprentice masons in the repair and restoration of the cathedral. The sustainability of a large building, in this case a cathedral, or any large sociotechnical system, requires planning. It requires a schedule of repair and maintenance to keep the decay, the dissolution, and the breakdown at bay. This research focuses on the role that “planning” plays in knowledge production, modes of learning, the maintenance of the built environment, and the efficacy and organization of vocational training under the UK and Scottish government’s modern apprenticeship scheme.