Relative and absolute elevations

[Wagurto]

We normally refer the site elevacion as NGVD elevations (absolute elevations) but the floor plans are refer as a relative elevations being the first floor 0'-0" is there anyway way to instruct Revit to handle two set of level information to account for relative and absolute elevations?
thank you for your answers.

[cliff collins]

see this:

http://forums.augi.com/showthread.php?t=122569&highlight=level+elevation

cheers