Hemis, let me ask you this question, how different is Revit from ACAD 3D in regard to the commands, icons and pull down menus. With ACAD 3D, I have done on small scales, volumes of earthen dikes, fills and removals from small sites, rebar quantities, concrete volumes, structural steel quantities. Sure these 3D quantities(weights) and volumes required a lot of work and memory, so is there any advantage, in light of the fact that I can use blocks to speed up my work? My understanding is that Revit requires computers with a minimum of 3 Gigabytes of memory.