creating one surface from two

[tebull3]

Is it possible to create one surface from an existing surface and a new surface. I have imported existing contours from CAD and made an existing surface and imported another file w/proposed contours. I cannot find out a way to merge them to make a final grading plan. will Revit Arch not let you do this? any help is much apreciated.

[dan302720]

Not quite sure I understand. If you have a seperate "proposed" surface CAD file, can't you just use that to create your surface? Why do you need to combine the two? Just create your topo using the proposed surface topo lines and call it a day.

[tebull3]

Sorry i wasnt clearer. I have existing contours and proposed contours that i want to show as a finished site in 3d for a presentation. if I make a new toposurface from the existing contours, I then need to subtract the proposed contours from the existing to make the proposed site. the existing site is very large and the proposed grades are only over a certain area. I can achive this by merging them in ACAD and then import but I wouldn't get the cut fill calcs. Is the only way to "grade" in Revit Arch manually with points or is it possible to cut one surface from the other?

[cliff collins]

Place the existing toposurface in the Existing Phase, and the proposed surface in New Construction Phase.

Then you will create a "graded region" which essentially "demolishes" the existing "cut".

You can then schedule cut/fill calculations.

cheers