Dollar bill folded to read "We need a revolution" referring to detailing BIM: no lines necessary
Written by Jay Zallan

Detailing BIM: No Lines Necessary

Revit is not a drafting software.

Revit is not AutoCAD.

CAD* is not BIM (*as understood in normal conversation).

CAD* processes Do Not Work In BIM.

Any part of “traditional” or drafting-based approaches will fail in BIM.

Yes, any and every… if you can find one that works let me know @JayZallan on the tweeties…

We are going to focus on Detailing; one area where value can be generated if applied comprehensively; namely Using Detail Components and never Lines.

If you are going to callout, or point to, or list in any way, or even look at now or sometime in the future; Use Detail Components for items (never lines), and Tags and/or Keynotes in place of text, to provide “the words and numbers.”
Toward a Zen of Revit: Less Text = Less Mistakes

Details using lines, arcs, circles & text are a disaster, but disasters land on a continuum and there are worse “details in Revit blunders:”

  • Linking .dwgs in (10% to 30% longer project time)
  • Importing .dwgs in (15% to 40% longer project time)
  • Converting .dwg linework to Revit linework (10% to 25% longer project time).

I understand that most offices have many hundreds of standard details or typical details that are used… With that in mind the workflow entails recreating (yep, recreate) all of the existing, ‘appropriate’ details in Revit natively, using only Detail Components for items that will be called out and specified… then use Keynotes and Tags instead of text when detailing. The goal will be overall and long term saving of time, money and will raise project and informational quality. The quality of the data “between” details using this setup will payoff for years, literally… not doing it will add hidden losses to every project, also for years.

Assess | Plan | Create | Validate

OK onto those details sans lines…
How-To Create a Line Based Family

FWIW: 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 lol)… The logic is: ‘When the line-based family 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.’

In the example below we are looking at a waterproofing membrane (image 1) to be specified.
-Perhaps even create and use Detail Components for generic items such as “WALL PER PLANS”, etc., when no wall is needed 3 dimensionally… Oh and YES, the wall below would NOT have the waterproofing membrane on the exterior of the finish… I merely use it as example.

Image 1

As described above, in the stead of using lines and pointing to them with non associative text we will rather build Line Based Detail Components or Detail Component line based (Image 2), as the family template is so named (depending on what year you read this).






Image 2 (Revit Circa 1842)

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) Depending on how built these can add “offset” for more productivity… or nest these together to make one family satisfy any dynamic future need (we will cover this in a future posting).
2) When there is a fundamental change in a detail component all the other instances will change, in every detail, on every sheet… the Tags & Keynotes too!!! Thus we leverage one Power of BIM: Change it once and it changes everywhere.

The following step-by-step should be clear if you have a decent understanding of Revit Family Creation.

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? Not really… one uses lines, the other three share a Detail Component of the line based variety…


Image 4 (Looks can be deceiving)

In the next image there is a change to the Detail Component from being “Bituminous Sheet Waterproofing” to “6 Mil. Polyethylene”… Note the text becomes instantly wrong… in a lot of places…





Image 5 (Change can be great)

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 find and create your Detail Components (line based or otherwise), AS DETAIL COMPONENTS for every specific case necessary… Word to the wise: If you have never looked at how many detail components there are in the OOTB Revit library, go bounce there asap!

Again, Revit is not a drafting software.

Happy Detailing!!


BIM Levels of Development - Kelar Pacific
Written by Kelar Pacific

Construction Design Phases vs BIM Levels of Development – Part 2 of 4

It’s important for contractors to understand the various LOD’s for each trade at any point so they can provide related cost and scheduling that is measured by the same design standards being used by the client and the designer. The understanding of how complete a model element is effects not only the Cost Estimates and Schedules, but also Constructability.

 LODs – Levels of Development

Definition ( –  The Level of Development (LOD) Specification is a reference that enables practitioners in the AEC Industry to specify and articulate with a high level of clarity, the content and reliability of Building Information Models (BIMs) at various stages in the design and construction process.

Level of Development vs. Level of Detail

LOD is sometimes interpreted as Level of Detail rather than Level of Development. There are important differences:

  • Level of Detail is essentially how much detail is included in the model element.
  • Level of Development is the degree to which the element’s geometry and attached information has been thought through – the degree to which project team members may rely on the information when using the model.
  • In essence, Level of Detail can be thought of as input to the element, while Level of Development is reliable output.

Does the project contractor utilize the designer’s LODs or Design Phases?

The LODs are not defined by design phases. Rather, design phase completion, as well as any other milestone or deliverable, can be defined through the LOD language. There are several important reasons for this approach:

  • There is currently no detailed standard for the design phases.
  • Building systems progress from concept to precise at different rates, so at any given time different elements will be at different points along this progression.
  • Design Phases are often utilized by the Prime Contractor as “Design Milestones.” These Milestones are utilized by the contractor’s estimators and schedulers. Their subcontractors should use LODs specific to their trade.

Levels of Design LOD Description - Kelar Pacific

  • LOD’s – Typically Utilized by Designers

We will continue this 4 part topic on Construction Design Phases vs BIM Levels of Development in our next Article 3.

Ed Wenz

Sage Estimating Consultant

5D BIM Estimating/eTakeoff


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