Which template and units should I use when starting a Revit project?

Start from the Architectural (metric) template, then immediately set Manage → Project Units: Area in square meters, and Length in mm for documentation (cm or m are used for some regional and urban-scale standards) — keep Length and Dimensions in the same system. One concept to internalize: units change only the display. Revit always models at real-world 1:1 — there is no "scale" in the model, only in views and sheets. Full steps: Start project set units →