Forums >> Revit Building >> Technical Support >> Topo elevation reports different value than actual location on z-axis in model

pvaughan

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Joined: Mon, Jul 2, 2018
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I started a project with a main level elevation at 84'-9".  I linked in the AutoCAD dwg file from the civil engineer and created the topo surface.  Everything matched up and worked accurately.  Click on the 80'-0" contour and it read as 80'-0".  I then received an updated topo from the civil which covered the entire site.  The first file was only a partial survey plan.  So I deleted the original topo surface, unlinked the original dwg file and added the new dwg file.  I then created the updated topo surface and moved it in the z-axis so it mated to the model elevations.  Now when I click on the top surface to edit a point at elevation 80'-0" identifies itself at 97' 5-1/4".  The point is actually at 80'-0" in the z-axis.   Every point on the topo surface reports itself as being +17' 5-1/4" heigher than it is actually located in the model.

I have played with the survey point and the project base point but 17' 5-1/4" differential persists.  I've even created the topo in a separate model file which I then linked to the main project model.  As soon as I bind the topo model into the main project model the 17' 5-1/4" bust resurfaces.

The dwg files have been scrubbed by wblocking out the topo contours lines and the propoerty lines.  The elevations all report correctly in the dwg file.

Any ideas???

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WWHub

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Look at what you wrote: "... I then created the updated topo surface and moved it in the z-axis so it mated to the model elevations....".   You don't do that.  If the CAD topo was correct, then the Revit model topo would be correct.  If your building is modeled in the wrong location, then that is what needs to be moved.

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pvaughan

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When the dwg file is linked the 0' elevation of the dwg comes in at / is set to the PBP project base pint which is set to the main level of 84'-9".  Therefore, dwg get moved down 84'-9".   With all the dwg contours are then the correct elevation in the model a topo surface is created referenceing the contour lines of the linked dwg file.  The topo surface contour lines are created however the 80' topo surface contour while occurring at 80' in the z-axis says it is 97' 5-1/4".  17' 5-1/4" higher than it actually is.!?!

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pvaughan

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I think I found the problem..................The model was originally started in Revit 2018.  Was upgraded to Revit 2019.  In R2018 the PBP, Survey Point and Startup Location were all N/S 0' 0"  E/W 0' 0" Elev 84' 9"  Once it we upgraded the Startup Location changed to 67' 3-3/4" which is 17' 5-1/4".  So there is the bust.  Relocating the model, the topo, the PBP, the Survey Point, nothing fixes it.

Sad face...............

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pvaughan

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I seem to have worked through the issue.  I started a new model, linked in the cleaned up dwg file from the civil engineer and created a new topo surface.  I then opened the project model file and removed all links and topo surfaces.  Saved it, closed it.  I then linked in the project model to the new topo model file.  Then I binded the project model with grids and levels.  All elevations are now correct.

I hope this works for any others that may be having a similar issue.

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