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!!


Kelar Pacific Autodesk University 2017
Written by Kelar Pacific

Autodesk University 2017 – What to look for in 2018

The BIG Picture – Autodesk® Forge, the Development Platform for the Future

Autodesk University (AU) 2017 highlighted Autodesk® Forge as the proven foundation for creating connective technology.

With Forge API resources, the AEC industry is no longer limited by multiple product silos. Now, everyone can develop custom applications and create connected workflows to reduce repetitive tasks and improve project insight.

Read More
BIM Levels of Development - Kelar Pacific
Written by Kelar Pacific

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

What is considered the industry standard of LODs?

Today, there is no official LOD Standard, or a requirement for one in the U.S.  Several organizations are providing LOD Specification Workbooks to help with the adoption effort.  These organizations include:

Any given project should follow the standard being used by the client and the designer.

To conclude the 4 part topic of Construction Design Phases vs BIM Levels of Development, confirm the following prior to starting on any project:

  1. Is the project governed by Design Phases or BIM LODs?
  2. If governed by BIM LODs, are the BIM files available for contractor use?
    If BIM files are available, be specific about requesting the file types needed.

    • Consider Autodesk’s Navisworks as an industry standard for reviewing and extracting quantities and other data. Typically Navisworks file formats (*.nwd) are sufficient.
    • The Navisworks Simulate software would likely be the minimum requirement for design simulation and project review.
  3. Is there an LOD Specification Workbook?
    • If so, is it available for contractors use?
    • Is the contractor bound to the LODs for their cost proposals for each defined portion of work?
  4. Is there a contractual agreement between the Owner/Client and the Architect/Designer that is defined around the LODs the prime contractor, and their subcontractors, may also be bound to?
  5. What is the prime contractor’s cost estimating expectations for each of the various subcontractors? And, will there be different LODs for each trade?
  6. Bottom line, be sure you are clear about how a project is defined and measured for progress and completeness by confirming the use of “Construction Design Phases,” OR “BIM Levels of Development.”

Useful Links for BIM Levels of Development and 5D BIM Cost Estimating:


Ed Wenz

Sage Estimating Consultant

5D BIM Estimating/eTakeoff


AGC, ASPE, SD Navisworks GC, CM and Specialty Contractor Users Forum

BIM Forum LOD spec guide
Written by Kelar Pacific

Construction Design Phases vs BIM Levels of Development – Part 3 of 4

What are the Definitions of BIM Levels of Development?

The following reflects the general consensus of the most widely used LOD Definitions:

  • LOD 100: A Conceptual Model where parameters like area, height, volume, location and orientation are defined.
  • LOD 200: An Approximate Geometry Model where elements are modeled with approximate quantities, size, shape, location and orientation.*
  • LOD 300Precise Geometry Modeling and shop drawings where elements are defined with specific assemblies, precise quantity, size, shape, location and orientation.*
  • LOD 350Includes Model Detail and element that represent how building elements interface with various systems and other building elements with graphics and written definitions.
  • LOD 400: Model elements are modeled as Specific Assemblies with Complete Fabrication, assembly, and detailing information in addition to precise quantity, size, shape, location and orientation.*
  • LOD 500As-Built Elements are modeled as constructed assemblies for Maintenance and operations.*

*Can include non- geometric information to the model elements.

How do you use BIM LOD Specification Workbooks?

BIM LOD Specification Workbooks are often required by the client and updated with each revision of a project’s BIM file. If so, it’s important for the prime and subcontractors to base the related progression of their cost estimates and schedules accordingly. The example below is created by the BIM Forum.

The BIM Specification is not a set of requirements as to what is modeled, when, or by whom. Rather it is a language by which users can define these requirements for their own firms or projects. A BIM Specification provides the following benefits:

  • Helps teams including owners to specify BIM deliverables and get a clear picture of what will be included in a BIM deliverable.
  • Helps design managers explain to their teams the information and detail that needs to be provided at various points in the design process, and to track progress of their models.
  • Allows downstream users to rely on specific information in models they receive from others.
  • Provides a standard that can be referenced by contracts and BIM execution plans.

View or download a copy of the LOD Specification Worksheet:
BIM Forum 2016 Level of Development Specification Workbook (Excel)

BIM Lod Specification Workbook Example

We will conclude this 4 part topic on Construction Design Phases vs BIM Levels of Development in Article 4.

Ed Wenz

Sage Estimating Consultant

5D BIM Estimating/eTakeoff


AGC, ASPE, SD Navisworks GC, CM and Specialty Contractor Users Forum

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


AGC, ASPE, SD Navisworks GC, CM and Specialty Contractor Users Forum

LOD Level of Development - Kelar Pacific
Written by Kelar Pacific

Construction Design Phases vs BIM Levels of Development – 1 of 4

Design Phases of Construction

The construction industry has utilized the “Design Phases of Construction” as milestones for measuring how complete the overall design of a construction projects was. Generally they include, but are not limited to, variations and percentages complete of Schematic Design, Design Development and Construction Documents.

The emergence of BIM – Building Information Modeling in the last decade has grown significantly. The percentage of “companies using BIM jumped from 17 percent in 2007, to 49 percent in 2009, to 71 percent in 2012.” (Source: Contractors Center Point).

With much of the design work now being done in BIM, the industry has developed more accurate methods of defining how complete a project would be at any point during the design process. This is done with Levels of Development, or LOD’s.

How do the BIM LOD’s relate to the historical Design Phases?

So now the question becomes “How do the BIM LOD’s relate to the cost estimating methods of the historical Design Phases?” The following outline provides a general overview of how they relate to each other with a couple of major differences:

  • “LOD’s express completeness down to the element and trade levels of design” where as Design Phases are overall milestones of the entire project.
  • “There’s no such thing as a singular Level of Development for a BIM design.”

Other questions raised by much of the construction industry include:

  • LOD 100 to 500 – What are the expectations and limitations for each, and by the designer or the contractor’s perspective?
  • How does each LOD impact the accuracy of 5D Estimating/Cost and 4D Scheduling/Time?

The Critical Path of Design

BIM designers are typically aware of the critical path of the design where more attention will initially be placed into the major elements such as Foundations, Substructure, Superstructure, Exterior Enclosure etc. Although it’s a reasonable approach to any critical path, does it support enough detail for:

  • The rest of the elements and trades requested to provide budget cost estimates?
  • Do the designers know how much detail is required for each trade to provide a cost estimate within 3-5% of the final design?
  • Does the owner or CM understand this as well?

We will go into Construction Design Phases vs BIM Levels of Development further in our next Article 2 of 4.

Ed Wenz

Sage Estimating Consultant

5D BIM Estimating/eTakeoff



AGC, ASPE, SD Navisworks GC, CM and Specialty Contractor Users Forum