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Site Model - What is the Best Way to Set the Elevation?


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I struggling to understand the best way to place my site model with respect real world elevation (feet above sea level). If my base elevation for the project is 150.0', I am currently setting Story 1, Level: "Finish Floor" to 150'. Is this even right? It feels a little weird to have the whole project floating so high up above the XY plane. Should Story 1 start at 0", and the design layer start at 150'?

I then wonder if I should also relate my site model's design layer with respect to Story 1. Currently, I'm placing my site model on a design layer that is not attached to any story, and set to a 0" elevation. The Site model topography is drawn at its real world values, so the whole model floats up above along with all the story related building assemblies.


Anyway, I would really love some feedback on what the best practice is for all this.




Edited by mgries
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What I do generally,

Design Layers relating to House Plan, are all storey aware ie tied to a real world story level, for example:

Story 1 RL = 54.5m

- Roof Plan - Story 1 - Offset from Story = 2.45m

- Floor Plan - Story 1 - Offset from Story = 0.0m

- Foundation Plan - Story 1 - Offset from Story = 0.0m


Site Plan Design Layer:

- Not tied to any story and design layer elevation set to 0.0m

- Site Model has contours relating to real world levels, and site model object is always set to 0.0 z value

- Then the House Plan related design layers are viewported onto the Site Plan design layer. And the viewport's z value is set to the desire RL/FFL. In this case 54.5m.  Apologies, the viewport should be kept at 0.0, as the Story level takes care of this step.


Hope that makes sense. Would be easier to sketch it out, but hopefully these words will do for now.



Edited by twk
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That's the way I do it too, however f,just note that for a recent new house on a sloping site we viewported the site design layer into the house floor plan rather than the other way around. That way, to tweak the siting of the house, we just move the Site DLVP around and our ground lines auto update on our house elevations & sections.

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I tried to work against it in the past.

As I wanted to have my Z coordinates readout according to my entrance level.

Just like I don't want to move my User Origin, and work with ugly numbers in XY

top view planes, but XY coordinate readout originated from my building Grid.


But trying to move my DTM or its Layer in Z - failed heavily.

So Elements or DTM accept the Z shift, others will ignore it.

Complete Mess.


So the mainstream recommended approach of using World Zs for Stories may be

the best choice.


And I think for someone like me that prefers to work in "Building Origin Coordinates",

I think the best way would be to do it the same way.

But using a permanent custom User Coordinate System, for Modeling.

Edited by zoomer
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