Thursday, July 08, 2010

Make Them Detail Components: A How-To

Recently I got a complement/comment posted to an older blog entry “Converting CAD Details To Revit Details: Just Do It...One way or another.” where it was said: "Great in-depth post on this difficult process. Well written, not confusing for anyone of any skill level. I work with the McGraw Hill Sweets Network, an online database where you can find all your cad detail needs." Well I do like a lot of the items on the Sweet’s sites (especially the BIM objects to be found there!!!) and think the publisher is doing great work for our industry without a doubt; but I want to make a distinction between what we NEED in BIM projects as opposed to CAD projects... Cad detail needs are not at all similar to BIM detail needs and it is just an error of imagination to confuse the two... an understandable error but error nonetheless (in most cases).

CAD detail are obviously good for CAD work flows but not for BIM projects as a whole. Basically CAD details are
lines, arcs , circles & text (all dumb objects and merely belief based) …we (read as I) need to revisit the whole concept of detailing in Revit in the hopes of shedding more light on how it may be best to work WITH BIM, rather than against the river that it is.

I have become an overwhelming advocate against the use of CAD details in Revit at all; if one can possibly help it. Then I have extended this to drawing lines in Revit...

I would like to forward the following postulate to those who have details drawn in Revit using lines, arcs, circles & text and still think that they have Revit details: you have not much more than sticky back details (yes, I have seen Revit details where nothing more is technically needed and in those cases I might agree that lines can be used... I just don't.

I'd still personally make the items into detail components, in case I ever use it again elsewhere -like the handicap symbol... and especially if the items use CAD lines that were "Revitized... that usually (read as most always) converts smooth curves into billion-segmented line nib-lets, creating bloated and slower files and worse than that hundreds or thousands of the ill-desired and dreaded Warnings. YUK:

From Toward a Zen of Revit: No Warning is a Good Warning (I am writing that presently)

Bottom line: details using
lines, arcs, circles & text are not as close to being as powerful as they can be with a true Revit (AKA: BIM) efficient work flow: (remember that was why you bought Revit wasn't it? The associative power & efficiency? Or was it that your client forced it on you???)

Next I propose a challenge: NEVER, EVER, EVER USE LINES IN REVIT.

Especially those lines converted from CAD files or details, as discussed previously... even though I gave that as an option in that older post...can't life be fickle? ...I said that was an is just a bad one for long term practice).

I understand that most offices have hundreds of standard details or typical details that are used as starting points
… With that in mind I do suggest recreating (yep, recreate) all of the existing, appropriate details in Revit, using only (OK; mostly only) Detail Components for items that will be called out and specified... then I suggest using Keynotes and Tags instead of text in as many cases as can be!!!

Toward a Zen of Revit: No Text = No Chasing

Dogmatic? Yes
Makes Details & Projects better? Yes
Saves time in the long run? I have found
Tastes great? Huh?

Using Detail Components (for every item) can be more possible than you might think right now... be creative!!!

OK onto those details sans lines...
I am not talking about lines within 'sketch modes' etc. either; in fact the detail component that we will be creating in this posting will ultimately use a line (though at the family level, so it doesn't count)… So I make a rule and break the rule… The logic there is When the line is used to make a detail component, it may work and look like a simple line but it has become far more than that... it becomes a Data Enlightened Object.

What I mean is: do not (in almost every case) use lines for pieces of Revit details, such as the example herein, where a waterproofing membrane (image 1) is specified.

-I even create or use Detail Components for standard/generically specified items such as “FINISH FLOOR PER PLANS”, etc… Oh and YES, the wall below would NOT have the waterproofing membrane on the exterior of finish... I merely used it as an example about these detail components!!!

Image 1

In the stead of using lines and pointing to them with dumb (read as not associative) text I suggest using “Line Based Detail Components” or Detail Component line based” (Image 2), as the family template is so named. Unless of course you want to chase text and naming around all of your details… hey; maybe I am wrong about this and you make so much money that spending time or
wasting time is of no consequence… If that is you then draw lines and link in CAD details and have fun with all the inconsistencies (CAD dimensions & arrows, etc.), time lost to re-re-re-modification and finally project slow down (too many CAD files will create a situation where Revit seems to work like it’s in molasses!!! Or like a Fucking Stupid Donkey)

Image 2

The procedures to ‘draw’ with these Line Based Detail Components once in a project are similar to pulling lines around; with a few main differences:
1) We cannot chain line based components together (awww ) , so click away my pretties
2) Detail Components can be brilliant!!! If we change one in a detail all the other instances will change… thus we leverage The Power of BIM: Change it once and it changes everywhere!!!

The following should all be clear if you have some pre-existing understanding of Family Creation. Uhhh; Revit Family Creation that is...

Making a Line Based Detail Component

1) Using the Big “R”, at the top/left of Revit (AKA: the Application Button) choose the flyout arrow next to NEW, then choose FAMILY

2) Select the Detail Component line based template (Image 2)

3) Create a line in the new family

-there, I said it… my rule is technically broken if you are thinking how I usually think...though in this case I am not being that literal (ahh, the contradictions of communication)

4) Lock it to the REF PLANES (Image 3)

Image 3

5) Flex the length
If all is working then move on, if not try again…

6) Save the family. (use a good naming convention & library location, right? But you knew that…)

OK ready for the proof? Here we go…

These 4 details (Image 4) are the same, right? Wrong… one uses 'them there' dumb lines, the others use a Detail Component of the line based variety… But you knew that (by now)…

Image 4 (CLICK THE IMAGE!!!)

Now, I am going to change the Detail Components from being "Bituminous Sheet Waterproofing" to "6 Mil. Polyethylene"...

Can you guess which one of them won’t change when the meta-data (Keynote value, in this case) is changed? … I’ll wait… OK, see (Image 5) for the answer.

Image 5 (CLICK THE IMAGE!!!)

Now extrapolate this type of change out to the multitude of components in the numerous details you may have and you can probably see the benefit of taking a little extra time up-front to primarily FIND and secondarily, Create your Detail Components (line based or otherwise), AS DETAIL COMPONENTS for every (or as close to every) specific case necessary… BTW: Have you ever looked to see how many detail components there are in the OOTB Revit library, let alone floating around on the web-o-sphere??? There are A LOT!!!

Happy Detailing!!!


  1. Yes! I tell people, NO text, NO lines! Use TAGS and DETAIL COMPONENTS.

  2. James,
    I did, I did!!! Hope you're well...

  3. We never use lines in our Revit models. But then most of the time we don't need details, either, because anything really complex is getting made by robots. ;-)

    If we didn't need to submit occasional permit / client review drawings we wouldn't even make sheets 95% of the time.

    OK, kidding aside, point is that you're absolutely right. The more that's really in the model, and smart, the more value you'll get later on when changes need to happen. Which is always. Also we've found the same thing you have: namely, that if it's smart and in the model, we're much less likely to screw things up when they do change, for it's obvious when something isn't going to work. Line-only 'dumb' details only make a disassociation between what's *really* in the model (which is what matters) and what isn't, and add another layer of complexity that we humans have to manage. And we're notoriously bad at things like that.

    Great post!

  4. So how do you handle hidden lines when using detail components, if you don't want to draw lines? What I have found is that when you start layering detail components on details components you will need to drawn in you hidden lines.

    While I tend you agree with you post, I feel that the rigidness of the line based family makes it hard to not use lines. Take drawing steel details for instance. Revit has a nice library of line based components, the problem is that these family don't take into account all the cuts, copes, haunches, and access holes that need to happen to the members. And it would be a royal pain to build these into the families, since each situation is different.

    Also if your detail is arcing your screwed because you can't draw an arc with line based detail component. You would have to create a new detail component, so is it really more efficient to manage all the detail components you would have to create in order to not use lines in your details.

    Dennis Nelson

  5. When you layer detail components simply use the "Bring to Front" or "Send to Back" buttons, etc... Hello??? The line based family in my example can be placed behind or in front of anything else... As to the arc, simply use a standard Detail Component... they can be made flexible enough for now...

    Either I don't get why you are arguing this point or perhaps you are not familiar with the "Bring to Front" or "Send to Back" buttons & other order choices available???

    In regards to: " is it really more efficient to manage all the detail components you would have to create in order to not use lines in your details?" Yes in most cases it is.

    We will be using Revit & these processes and components for years to come, no? There may at times be needs for using dumb lines, arcs and circles, etc. but the less of them the better in my mind; and judging by the esteemed colleagues who have added their comments agreeing with this BIM-centric concept; I say even more emphatically NO LINES + LESS TEXT = BETTER BIM.