Monday, July 18, 2011

Alternate Units - Seriously?

I encounter the request to show alternate units in Revit every now and then. I see the subject pop up in user forums like AUGI and too. The superficial response is, "Nope the dimension styles in Revit don't have a "show alternate units" option like other CAD software."

Seems simple enough to me for the software to provide it doesn't it? I'm not a programmer so I won't speak further for them.

    Below the surface what's always bothered me is, why???? - Some bureaucratic response? "Just show both units!" Some generic project wide uniformity? -

No this is not some fanboy defense for Revit's lack...I really don't get the notion that we have to provide alternate units for everything. What practical purpose does providing overall building dimensions in both units of measure serve? If the project is to be built in China, or Europe, or the Middle they really care about imperial units? Does the window manufacturer that builds imperial based products care about the metric equivalents? Is the framer going to compare the values before they nail in the studs? Is including both units meant to be "easier" for those team members who can't be bothered to become acquainted with the appropriate unit of measure?

How about providing dimensions that show the units that really matter to the poor sap trying to build the project and leave the rest of the clutter off the drawing? I can understand a manufacturer including both when they are seeking pricing for manufacturing something from a variety of sources including overseas vendors. But then often metric and imperial numbers have some fudging involved to cleanup the numbers (3'-0" vs 900mm doors, shaved 15mm off the imperial size).

Backing up...sure, "please "factory" GIVE us alternate units." But using them in practice still ought to be based on reasonable application versus an arbitrary "just show both", some degree of appropriate use. My $0.025

At this time we've got some "ugly" options.
  • Add the alternate values as an override suffix to each dimension (make that really really ugly).
  • Change the unit of measure for the project dimensions and plot the set again (PDF only hopefully) It does nothing to resolve "messy" conversion numbers like the door example above.
  • Add additional dimensions that don't show the "lines" and adjust the dimension value so it is next to the others (pretty darn ugly but at least tied to real elements/values).
  • Provide and use alternate dimension styles that show the appropriate units for what is being communicated and based on where the project will be constructed. (maybe you can sense my preference here?)
  • Use API to add/update alternate unit suffix for us, don't know if API actually permits this though. Programmers confirm/deny?


Kelli Lubeley said...

Our firm works on government projects that require both imperial and metric dimensions. While typically I would agree with you, on these projects our users are doing double work when alternate units solve this.

Matt Mason said...

Use API to add/update alternative unit suffix: DENIED.



I think, Steve, that your vision about the real need of alternate units in Revit is absolutely correct and rational. And I suscribe it. But also it is too "Central". I mean, placing yourself and looking the world form a kind of central or dominant point of view, could be like looking into a mirror: you see yourself, that is not different of what you expect and can't avoid to see. But how would it be to be seen fom inside the mirror... well I think that for the "externals" the need of those alternate units has to do with something like that. For example, I am Chilean. When chileans goes to the cinema to see an american movie they always choose the subtiteled version. Even kids (as soon as they feel they can read fast enough) prefers to see Jack Sparrow or Buzz Lightyear in english. It gives us the feeling that you will not be missing anything. That you will get the full and real experience conceived in the movie. That the real sound and voice of the characters is better than the best effort of the translator. You may say, of course, that it is not only not completely true but even stupid: subtitles are also an important distraction that will interfere and never substitute the experience of a movie conceived in your own language. But subtitles (or alternate unis) is a way of making you conscient and aware that sooner or later you will have to deal with an untranslated segment, with an ineffable portion of a dialog... like the shaving of those 15mm you mentioned. That you will have to arrange or put somewhere in the work the differences of unit systems, the infinitesimal little architectural tricks of the Tower of Babel.

Bill McLees said...

We have done several US industrial plants using imperial units. These facilities often house equipment provided by Japanese or German vendors. And the plants sometimes have foreign owners. Having both units on the drawings allows personnel in each country to review our drawings using the units they prefer.

Steve said...

Thanks for the comments! Bill I can see what you mean from the owner/user's perspective that a general application of both units would make life "easier" for them.

As the previous comment stated my complaint is a bit narrow in scope.

It would be nice to be able to say, "yeah sure Revit does that!"

seandburke said...

As Kelli states, GSA and other US federal projects not only require it because the owner says so, it's Federal Law.

Some beaurocrats decide every ten years or so that this country shoul begin to get ready for the impending switch to metric. Of course getting that to ever happen will take more than an act of Congress.

Anonymous said...

In and ideal world we would abandon Imperial units (as they have done in England) and go to metric.
Alas, we live in the USA and think the metric system is some socialist plot to turn us all Canadian....universal heath care could not be too far behind.
We have clients that source some of the contract work to overseas (ie not USA) The clients understand feet and inches, most people in our office understand feet and inches, overseas vendor understands metric.
We also use it to give millworker fractional inch dimensions...which besided beign preferable, makes designing easier and makes reading shop drawings which often come to us in inches, easer.
It's a matter of communication, not philosophical polemic, or dogmatic stance on how some blogger feels about the purity of a dimension methodology, or some unreasonable bureaucratic decree.

I archicad, all I had to do is turn on alternate dimensions. I suspect despite the disclaimer otherwis the orginal post was more inormed by the fact that Revit does not support such a feature.

DoTheBIM said...

How do you make dimension types without lines?

Steve said...

See "da" new post!

Anonymous said...

I am working on a US government project in a foreign country that is on a US base. As it will be owned by the US but built by a foreign country, we must document using both imperial and metric. All of our program requirements are in square feet...but will be built with metric materials. We will likely use a metric template and convert duplicate dimensions to imperial. but there is a real world use for doing double dimensioning.

Steve said...

Yes, I get it. I was grumbling about a specific requirement that didn't seem based on a practical reason at the time. It would be easier if we could just turn on the "option" eh?