Efficient Drawings

A few weeks ago we were talking in the office about how much wasted effort is involved in doing our work. I wasn’t sure the Powers-That-Be were really getting what we were talking about and I knew that the over-drafters wouldn’t follow the discussion well either (if they could, would they still be drafting for the sake of drafting?) so I decided to run a test on a drawing that I knew was overdone.

The original drawing contained nearly 2,000 objects. After thinking it through a bit and re-creating it (I traced over an Xref to make my job easier) I got it down to about 200 objects… just 10 percent of the original. I printed it out and showed it around and everyone started to understand even if they’re not sure yet how to get there.

I made a PowerPoint out of the example for grins and posted it up over at slideshare as part of a brief exploration of that site. I also embedded it below.

I am continually amazed at the potential of the internet to make connections. In the short time it’s been on the site it’s been viewed over 30 times and downloaded once. Not big numbers to be sure and some of them are likely people I’m working with but not all. It’s amazing that with so little effort you can start to influence people you have never and likely would never meet.

Think about what would be possible if you tried.

Off topic rant… sorry ’bout that.

If you’re going to use a 2D CAD program to create drawings I think it’s important to look backwards to when drawings were produced by hand with pencil and pen. The width of the pencil lead or pen tip was a determining factor in the level of detail you could place in a drawing. As was the understanding of how long it would take you to erase and recreate the work should it change.

A parapet, for example, in a building section at 1/8″ = 1′-0″ might be nothing more than a 3 lines. In a 3/4″ wall section you might add a bit more information (enough to suggest the metal parapet cap). And you weren’t likely to see much more detail than this until you got down into the 1 1/2″ = 1′-0″ details. Changes to the detail usually didn’t necessitate changes to the building or wall sections thus making these changes was quick and easy.

One common method of using CAD is to place as much detail as possible into the building or wall sections and to simply zoom into them for the details. Sounds reasonable and is certainly easy to initially implement; after all, once the parapet is drafted in the first section it’s simple to copy the section to use a start for other drawings. A lot of ink is placed on the sheets in a short period of time and gives the illusion of work and thought. But what happens when the parapet detail needs to be changed under this methodology?

Well, if you’re going to do it correctly you need to find each of these sections that were copied from the original and make the appropriate change to each of them. What took the pencil drafter an hour or so might take the CAD operator an entire day… or more!

We need to get better at managing change. If our processes don’t acknowledge and allow for change easily then we are not managing change, the change is managing us.

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3 Responses to Efficient Drawings

  1. Great topic. We have this sort of discussion all the time. A partner in our firm, who drew by hand and did CAD for a long time, calls it “falling in love” with your drawing. The sad part is that I see people re-iterating things over and over, drawing meaninless detail that they can’t even explain sometimes, but they feel good about their work. Now that I primarily use Revit, I love to turn on the lineweights and it makes me think twice about showing multiple lines to display built up roofing! Isn’t one enough? How about showing counter flashing in a 1/2″ section? Just give a hint that it’s there (basically, make sure it can work!) and then detail it in the appropriate detail views at 1″ or 1 1/2″. I can’t stand roof details calling out the wall components that are already shown in the wall type details. To manage change, it’s important for us to show things in one place so we know where to go to make those changes. The biggest mistake we make often is to not properly manage our time on jobs; overdetail some areas and totally miss others.

  2. l54la says:

    in acad this is hopelessly messy.

    but doesn’t revit have the advantage of “automating” visibility of elements/objects/whatever in relation to the scale being printed? doesn’t revit have default assumptions regarding lineweight, visibility, etc vs print scale & print purpose (sales renders vs CDs)?

  3. I always have this argument with the old 2d Cad operators!
    I always bring it back to Speed of Documentation. I draw up using Metric, & most of my Sections etc are at 1:50, I use a 0.7m Pen weight on most of the system Families (walls, roof, floors etc) it hides alsorts of stuff. Its a great thing to do – Never mind the Details – they can come if & when the project goes forth.
    I know of 1 CAD operator that did the above Parapets for 2 weeks – then in 1 swoop we removed them from the project – all that time wasted.

    I think people have to sit down & work out what stage there drawings need to achieve & only do that – nothing more. Its Hard. But the results speak for themselves – a Set of Plans, Elevations & Sections of a 200m2 house in a Day.

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