Using Revit 2013:
In the material editor in the first drop down box with the material name there is box where you can enter the material cost, and you can access this from a Multi-Category Material Takeoff Schedule, and multiply by the Material Area, which works.
This allows walls for example to be costed with a list of materials with amount and total cost.
But Costs change over time, and we usually deal with this using a Tender Index, which updates Quarterly.
So I want to include with the material cost the tender index at the time the cost was established (Inevitably new costs will get added at different times with different tender index values)
Then I would set the Current Tender Index in the project, and in the schedule I could include the formula:
Current Cost = Current Tender Index x material cost / tender index
That would allow me to track changing costs over time and allow for regional variations in tender prices using published price book data without having to amend every material cost.
How can I add a parameter to the material itself, that can be accessed from a schedule?
It must be possible as there is a button at the bottom of the editor labelled custom parameters, but this doesnt seem to allow any to be added and currently is blank.