Revit refuses to build my stair — “impossible” riser count

The stair type’s rules are stopping you: Maximum Riser Height (e.g. 175 mm) and Minimum Tread Depth in Edit Type are the constraints behind every "impossible" stair. Set Base Level, Top Level, riser count and tread depth in Properties BEFORE drawing, then draw the run until it reads "0 risers remaining". If the geometry genuinely can’t fit the rules, change the stair type’s limits — don’t fake it with dumb geometry, because a modeled-by-hand stair silently stops short the moment the storey height changes, while the Run tool recalculates. Full steps: Stair by run →