The Phantom 1/32": Dimension Override

[scz]

This is wild.
See the attached images.

I placed one dimension between two walls as shown in the RevitDim_01.jpg image that comes out to 27'-3".

I added two more Witness Lines using right click-Edit Witness Lines. The subsequent dimension string adds up to 1/32" less than the total of the split dimension!

Are tolerances to blame? Ideas for fixing this?

[DaveP]

Chances are pretty slim that Revit is lying to you. You've probably got something slightly off which rounds up when totaled.

Try going into your Dimension Type properties and (temporarily) changing the Rounding value to 1/256".
Select a dimension,
Go into it's Element Properties
Click Edit/New
Click Units Format
Uncheck "Use Project Settings"
Set Rounding to "To the nearest 1/256"

Once you've found out which wall is off, move it into place.

Don't forget to set the Dimensions back to 1/32" when done.

[Calvn_Swing]

I've noticed things like this many times after tracing over CAD plans in Revit, or after people move things around by dragging. They frequently check their work by using the dimension tool forgetting that it rounds to the nearest something as defined in the project units settings. Here's how I'd fix it. Make three reference planes and dimension them just like what you've got in picture 2. Align one to the side you don't want to move 1/256th of an inch or whatever you're off by. Then, click on the remaining two and type the exact dimension you want into the dimension string for the remaining two reference planes. Then, align the elements to those reference planes. (don't lock anything btw.) Then, delete the reference planes and dimension your elements again and all should be well.

When you trace CAD or press and drag, you're working at an accuracy level of roughly 1/256th of an inch. With the rounding settings in your project at 1/32" it is fairly easy to get some discrepancy in dimensions if people aren't careful. I had one project where a wall was 1/512th of an inch off, and it took a while to figure out which one. Personally, I prefer setting my dimensional rounding at the project level to 1/256th of an inch and tell people to model things right rather than count on rounding to make their dimensions look pretty. Also, tell people to check their work using the measure tool rather than the dimension tool as rounding settings do not apply to the measure tool. They'll see if they're 256th of an inch off.

Good luck!

[scz]

Thank you so much for the responses.

This project is in fact traced in CAD.

This is a pet peeve of mine!
If things are drawn right in the first place at the sacrifice of some schematic speed...

Invaluable help.
Thanks!