Units and Zone

[defiore.paul]

I am starting to create a new Civil design project.  We just received the survey.dwg.  If I keep the survey.dwg with the Units and Zone from the surveyor (I trust the surveyor), then use my Proposed.dwg template file to xref in the survey.dwg, then zoom to where the survey lands in space and draw my proposed design on top of the xref but did not change the Units/Zone in my Proposed.dwg to match the Units/Zone of the survey.dwg, will this have any negative effect on design or construction?  thanks

[rl_jackson]

Yes this could have a negative effect. You should and need to be on the same system as the surveyor. This will also make future site work and construction easier especially since most of the time the survey that does the original boundary also dose the construction stakeout work as well. 

[jefflambert9091]

Be careful with the drawing units/insertion scale too! The Feet/US survey feet and give you troubles. I set mine to Unitless. Takes everything out of the equation. 

[lynn_zhang]

Hello @defiore.paul ,

Just checking to see if your problem has been solved. Does the respond from our experts above help answer your question? If yes, please click on the "Accept as Solution" button in their reply or let us know if you still need help. Thanks!

[AllenJessup]

The real problem is that the Units and Zone settings done affect anything in the drawing. They affect how data is inserted, exported and shared. When you draw a line 20 units long. The program doesn't know if that's 20 feet, 20 miles, 20 meters or 2 parsecs. It applies the Units and Zone after the fact.

If you Xref the Survey drawing. You will be drawing in the system of that drawing. Even if you Units and zone are set differently. What will be wrong is if you export a drawing, coordinates or an XML file that has the system identified. The exported file will say it's in the Units and Zone of your design drawing but the coordinates will match the Survey drawing. This will cause confusion  and possibly errors in design and stakeout.

It's best to decide what coordinate system the work will be published in and move everything to that system. If possible. Have the Surveyor re-issue the work in the system you want.

[wfberry]

Allen:

I think you need to re-write your 2nd paragraph.  It seems misleading to me.

Bill

[AllenJessup · Accepted solution]

Bill,

Maybe an example will make it clearer. If I get a Survey drawing in System X. It could be a published system or a random system. I then Xref the Survey Draing into my Design Drawing that is set to NYS HPGN East US Survey Feet. I then design the project on top of the Xref. Then I export an XML or publish coordinates. They may say that they are in my NY State Plane coordinate system. But they will actually be matching the System X from the Survey Drawing.

If the Survey drawing is in a random system then the design will be in that random system no matter what Unit and Zone I set in the design drawing.

I could compensate by rotating and scaling the Xrefed Survey Drawing in the Design Drawing. If I had matching points in bot drawing. I don't like doing that but have when necessary.