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View Full Version : Material Take Off Revit vs CAD



dvemis
2009-04-29, 08:32 AM
I have 2 small concrete structures modeled in Revit 2010 and I need to extract data for concrete volume and formwork area. I have defined a work breakdown structure so I can get my quantities of material for each element.
Also I have exported to CAD the model and I have done a data extraction for the same materials : concrete ( obj volume) , formwork (contact area).
The purpose of this exercise is to find the most accurate and faster method to extract data that I need.
For volume extraction I like Revit better since. It is automated and the schedule is parametric linked to the model. Using CAD is not bad however it is a manual process since there is no option in data extraction to extract the mass properties of the object.

For formwork extraction ( contact area) is a different story.

In Revit I learned this method of painting the surface contact with a material defined as formwork and produce a material schedule. The results are not accurate and the error comes from 2 reasons 1-For suspended slab (roof) soffit the contact area goes beyond the intersection between walls and slab adding formwork to the final results.2-Because the walls have different thickness I have an extra quantity of formwork at the joints where the thickness changes. (please see attach)

In CAD I have exploded the objects , deleted the surface which is not formwork and run a data extraction. The results were very accurate.

I guess the help I am asking for is to find a better method in Revit to extract formwork quantities ( contact area).

I have attach a Revit / CAD model and a spreadsheet with comparison between CAD and Revit data extraction.

ec03108190183
2011-12-02, 12:50 PM
hi

i see that this is an old post but do you had any reply?

regards