Monday, 24 September 2012

USACE and Level of Development

The US Army Corps of Engineers has recently released their Minimum Modeling Matrix or "M3" - available at This document is a spreadsheet that contains three worksheets: Instructions, Modeling Requirements, and Scope-LOD-Grade.

Referring to a post on All Things BIM ("Moving Forward With LOD"), the USACE M3 document utilizes the AIA LOD definitions and classifies the built environment with a minimum level of required information from design and construction teams.

They did a nice job in categorizing the built environment their own way and then including references to Omniclass, Uniformat, AND MasterFormat. You can even filter the Scope-LOD-Grade worksheet in column A to show different level of specificity (as in Uniformat, Level 1, 2, 3 and 4).

LOD gets a 'Grade'

USACE has utilized only the 200 and 300 levels of development, and has limited use of 100. They specify the LOD in only one column and then they have introduced a concept of 'grade' as an additional qualifier to the LOD. Here's the explanation of the Grades according to USACE:
A = 3D + Facility Data
B = 2D + Facility Data
C = 2D Only (drafting, linework, text, and/or part of an assembly)
+ = Original grade (A, B, or C) adjusted for contract changes and field conditions
When you put the LOD together with Grade, you get an interesting interpretation of the original level of development scheme.
You can see in the sample above that within Fixed Furnishings, it would be acceptable to include Window Treatments in the model as generic-2D elements (200-B), whereas Casework must be specific-3D elements (300-A). To be honest, I'm not sure how I would model Fixed Art at 100-B...

Also note that Record Modeling and As-Builts are included in the USACE minimum requirements. The plus (+) symbol next to all There is often a question in our industry about the difference between the two and my opinion is as follows:

  • Record Model - Design model that has been updated with any recorded changes (usually via RFI or Change Order) during the construction process. The model is NOT updated with in-field conditions. This seems pretty straight-forward for geometry - much different when you're talking about data.
  • As-Built - Design model OR fabrication model that has been updated according to installed conditions. Again, if we're talking about data, that usually means serial numbers and other detailed information that would not be part of the design model.
At an Autodesk University panel presentation, the team from USACE clearly explained that they see the Record Model and the As-Built Model as THE SAME THING. Notice in the image above that the column heading is "RECORD MODEL (AS-BUILTS)." Remember this if you are working or will be working on a USACE project in the near future.

Modeling Requirements

The CAD/BIM team at USACE has also created a worksheet for "Modeling Requirements" that lists a very broad statement for each major building system - organized to Uniformat Level 2 specifications. This presents a potential 'scope-creep' situation for design teams in that the Modeling Requirements do not describe different levels of modeling specificity. This type of modeling specification is being examined by the LOD Specification Workgroup of the AGC and AIA mentioned in the All Things BIM article above.

Why is the Modeling Requirements table potentially dangerous to a design team's scope of work? Here's an example...if we look at D40 Fire Protection, the requirements are as follows:
"All Fire Protection elements including all piping, valves, and seismic bracing shall be modeled with necessary intelligence to produce plans, elevations, building/wall sections, riser diagrams, and schedules where applicable."
At a more generic level of development (200), an engineer would likely not include valves and seismic bracing; therefore, where do these requirements apply?


Overall, I applaud the USACE CAD/BIM team for their effort to point the AEC drivers in the general direction of travel - considering the AIA E202 was merely a road map. I hope they can refine their approach over time to allow greater clarity in a more simplified approach towards establishing minimum modeling standards. It will be quite exciting to hear about some project case studies as teams work with the USACE in the near future.

Friday, 21 September 2012

AIA Digital Practice Docs and COBie Guide

As Summer 2012 draws to a close, two interesting releases that are quite relevant to our buildingSMART efforts. First, the American Institute of Architects (AIA) has released updated versions of their "digital practice documents" for public comment. These documents represent an evolution of the E202 BIM Protocol Exhibit into a more complete project execution plan. You can visit to download the documents for review or read the press release here:

The comment period for the AIA documents will close on October 8, 2012 (extended from the original September 24 deadline).

The second release is the COBie (Construction-Operations Building Information Exchange) guide from the buildingSMART alliance. The guide provides information about organizing and delivering COBie formatted data. You can download the COBie guide here: 

Thursday, 20 September 2012

Help! My Model has been Deleted!

If you've been in the BIM manager's seat for long enough, you might have seen this support request come across your desk a few times. In Revit, it's quite a convincing shock to open a project file and find nothing but annotation, but don't fret...the problem is most often just a workset visibility issue.

We recently encountered this problem in our San Francisco office, where a user reported that all the model elements have been deleted in a project. Do we need to restore the model from backup, rollback the worksets, contact Autodesk and report a bug...? First let's examine the scenario...

One team member had been working on the same model, but their immediate task was simply to perform some editing to annotation; therefore, they had closed all the User worksets. Remember, when you open a workset-enabled file, you can click the dropdown arrow next to the Open button to select the Specify option:

With the Specify setting, you can select all the User-Created worksets and set their Opened status to No (select them all in the list, then click Close).
This is good for performance, but obviously not good if you actually need to see some of the model components as you work! 

Back to our story...this user synchronized with central and then another user began to perform some work. Now, this scenario should not affect anyone who is currently working in the same project model, but I presume it may be related to the script file our project teams use to automatically create new local copies. If user #1 had synchronized with all worksets closed, and then user #2 created a new local copy of the model and opened the model with the default workset option (Last Viewed), they might have all User-Created worksets turned off without the benefit of the Opening Worksets dialog box to indicate what is open or closed.
What's the moral of this story? We strongly recommend using the Specify option EVERY time you open a local copy of a project model. Remember you can also set the default action for opening when you first create a central file. Click on Options, and set the Open Workset Default to Specify as shown below. You can also check out one of our previous posts with other valuable tips on finding hidden elements.

Wednesday, 19 September 2012

LEED Calculations with BIM

HOK’s own Amy Patel – a buildingSMART Specialist – gives a complete presentation to the New York City Revit Users Group (@NYCRUG) about the use of a BIM platform to calculate specific LEED credits. While she demonstrates using Revit, these concepts can be applied to any BIM platform.

Check out the recording…