Project Units-Rounding/ Best Practices

[thomas.denney836893]

What level of 'Rounding' under the PROJECT UNITS> LENGTH category would you say is considered to be best practice for an office template and standards? We've had the debate over nominal vs actual in our office, and actual it is. Now the question has arisen: what rounding do we set the project units to? Default(out of the box) seems to be 1/32", although if some people had their way I could see it being set to nearest 1". What are other people's feelings on how high the tolerance should be?

[Tommybluegrass]

When Imperial Units are required we build to a 1/16". Some equipment and parts built or installed require smaller units. In this case the units are driven by the vender drawing. Which could have values of 1/32 or 1/64. So this leads to dimensioning and what is set to place the correct dimension per units desired. This is set in a dimstyle and overrides or different dimstyles for each type needed can be created and used from one or more templates as needed. Bottom line on fab or shop drawings. It is very hard to measure on paper these small units. If building a part in the shop then these units are very important. So what rounding to use? Depends. For a office template using Imperial units set it actual and draw full size 1 unit = 1 units in model and dimension exactly using viewports to a viewport scale that meets the needs of the design and the needs of the craftsman to build the part or assembly the fabrication... Tommy

[rob.127056]

We have had this debate in our office many times. I say round to 1/256th. The reason for this is that it forces everyone to make sure that when they place an item in Revit they think about the actual distance it is from other objects, especially walls. I don’t ever want to see a fraction on an inch in my dimensions, although sometimes it is impossible to avoid. At least if you round to 1/256 it is obvious when you dimension and then it can be adjusted accordingly.
Also, I have seen in many instances that rounded dimensions in a long string of dimensions don’t add up correctly to the overall dimension. If you are drafting to 1/256 it forces you to correct the fractions and therefore the overall adds up correctly.