If you run an MEP consultancy or contracting business, this will be familiar. You've scoped the modelling work. You've agreed a fee with a freelancer or outsourced team. The markups are packaged and handed over. Then the architect issues a new ceiling strategy. The structural engineer adds fire compartment beams in two corridors. The riser that was signed off at Stage 3 no longer fits the revised layout. The scope just changed — significantly. But the client is reviewing 2D d