Wednesday, October 08, 2008

AGC BIMForum Review

Last week I attended the Associated General Contractors of America (AGC) BIMForum - a focus group for contractors implementing Building Information Modeling.  The group meets quarterly and features John Tocci, Sr. of Tocci Construction of Massachusetts as host/emcee presiding over the intense 2-day agenda of presentations, case studies, breakout workgroups and "rapid-fire technology demonstrations."  A conference of this nature differs from the likes of Autodesk University or the Bentley Empowered Conference in that one won't find 'how to' classes, rather industry professionals - including architects, engineers, subcontractors and fabricators - sharing their experiences and crafting solutions to today's and tomorrow's BIM challenges.  This meeting was held at the Fairview Park Marriott in Falls Church, VA outside Washington, DC and carried the subtitle "BIM With Others."  Because most of the sessions were focused on integrated practice and model exchange best practices, I found almost every session relevant and interesting, amassing 12 pages of digitized notes with my Adapx pen (more on that in a future post).


Some obvious contributors of note included Laura Handler (Tocci), Jan Reinhardt (Adept Project Delivery), John Tocci, Jr (Gilbane) and Davis Chauviere (HKS) who chairs the Designers Subforum.   There were many others who provided valuable content and sponsorship (Autodesk, Bentley, Vico, Solibri, Tekla, Vela Systems, Trimble, etc.) but I cannot list them all.

What Kind of BIM?

Very early in the conference, John Tocci introduced a new nomenclature of "lonely BIM" versus "social BIM."  These concepts would gradually weave throughout almost all the subsequent panels and presentations and seemed to be a clarification of the terminology set forth in the book "BIG BIM, little bim" by Finith Jernigan.  The 'lonely' variety depicts BIM when utilized primarily for production gains within a single company.  In contrast, being 'social' implies the sharing of building information models with others either downstream or upstream in the building lifecycle.

Use Cases

The first presentation was given by Marwan Bakri from the federal division of HNTB.  He illustrated uses of Revit both in the 'lonely' and 'social' sense.  Revit was used in the proposal and early design phase to determine the most economical exterior wall configurations, simply by generating wall schedules with some simple massing models.  On another case study, they illustrated a modification of their modeling techniques to better coordinate with the contractors.  Such techniques include modeling walls for each level - not multi-story, using colored solid fills to indicate wall types for estimating, and modeling individual concrete slab pours.

Next was a group of presenters discussing model exchanges for various disciplines and trades.  Chris Fischer (Schuff Steel), Dan Gonzalez (Swinerton) and Stacy Scopano (Tekla) spoke about exchanges in the steel industry, most telling was Fischer's highlights of what works (wireframes and grids, relative geometry such as top of steel datum, some sizing if the designers modeled correctly, and quantities) and what doesn't work (material grades and sizes when approximation is used by a designer or engineer, column rotation in data translation, lack of curved geometry in SDNF format, editing dimensions/text in lieu of real modeling and anecdotes of Revit to CIS/2 translation taking 24-30 hours).  Dan Gonzalez spoke of the work he supervised on the USC School of Cinema which was a followup project for George Lucas after the much heralded Letterman Digital Arts Center.

For the MEP sector, Randy Richter (Zach Sargent) and Eric Winslow (Superior Air) discussed their use of intelligent duct design software as well as their relationships with engineers.  They frequently work directly in the same files as the engineers in what can be construed as a 'design-assist' effort.  A "Design-Assist Responsibility Matrix" illustrated the planning of coordination in such an arrangement. Furthering the discussion, an interesting quote:  "A trust-based approach rests on the assignment of benefits based on the recognition of risk."

Will Ikerd of RL Goodson, Inc Consulting Engineers spoke of the curtain wall industry.  He had some clear examples of three basic forms of models:

  • A dimensional control model - which was merely a Revit massing model which helped determine and manage the overall project geometry
  • A structural model - for curtain wall, consisted of generic 'glass' walls with the thickness approximating the overall depth of the curtail wall system.  This is used for clash detection against the structural model.
  • A fabrication model - parts of the Revit design model are transferred to Inventor for component fabrication.

Finally, Laura Handler (Tocci) and Sarah Vekasy (KlingStubbins) spoke of their experiences while co-located under an IPD agreement for Autodesk's new AEC HQ in Waltham, MA.  Before starting out in the design process Tocci and KlingStubbins sought to establish protocols for model organization in Revit.  Worksets would be based on Kling standards, phasing based on Tocci's.  In the end, much of the protocols were hashed out on the fly because the teams were working in the same office.  Of interest is the change in modeling techniques including 'wall splitting.'  The structure and finishes were modeled as separate walls, allowing for more accurate phasing simulation and enabling the coordination of the model with a Trimble Total Station for precise partition layout.  Dimensions on plans were only added where required for building department approval, as there was no method for submitting a 3D BIM within the local municipality.

Breakout Workgroups

In the afternoon of Day 1, the conference participants were invited to participate in one of many focus-based workgroups.  There have been several times in my life I wish I could replicate myself - this being one of them.  I decided to join the Architect's Workgroup, chaired by Davis Chauviere and featuring a lead-off presentation by John Tobin of EYP. (By the way, John has a brand new Building the Future article on entitled "atomicBIM: Splitting Data to Unleash BIM's Power").  The discussion within our workgroup quickly focused on the concern of BIM hand-offs changing the risk equation.  Do Architect's inherit more risk when they are producing a virtual building rather than heiroglyphics intended to be translated by the construction team?  As I mentioned in a previous post, our firm has crafted a BIM disclaimer to insulate us from this perceived additional risk; however, this stands in the face of collaboration and trust.  What if the Architects started to chip away at the 'disclaimer shield' and identified certain elements within the model that could be trusted.  This would lead to a prerequisite quality assurance process for shared models, but might just start to alleviate the concerns of project constituents not engaged in integrated project delivery.  Of course, designers and engineers would have to be compensated for the elevated integration!

Day 2: More Case Studies and Risk Management

Viktor Bullain of Vico spoke on behalf of an ill Matt Ryan (Webcor) and brought to light the issue of "level of detail" as one of the primary practical concerns with BIM hand-offs.  Vico and Webcor have been collaborating on a "Model Progression Specification" or MPS - which is available as a free download at under "Tools/Publications."  The MPS outlines the following macro levels of detail and their respective "authorized uses:"

  • LOD 100 - Not necessarily 3D, used for cost per area or 'zones' and total project construction duration.
  • LOD 200 - 3D, but generic models; locations known, cost can be estimated in ranges; exterior systems selected.
  • LOD 300 - Construction means and methods known; dimensions, capacities and connections are specified; clash coordination.
  • LOD 400 - Shop drawings and fabrication details; committed purchase prices of assemblies.
  • LOD 500 - As-built or record model for facility operations and maintenance.

Next, Doug Green of Marsh delivered a sobering, but profound presentation on "Risk Management Principles applied to BIM."  On IPD agreements, he simply states that the insurance industry does not yet have a policy to cover such a tri-party team.  Insurance is fault-based, but IPD requires a no-fault arrangement.  Who is to blame if someone gets hurt on the job?  One key concept which resonates with my duties at SOM is the risk management concepts of "avoid and transfer" versus "accept and manage."  I think our workgroup discussions on "chipping away" at the BIM disclaimer were bolstered by this comparison.  Green also emphasized a warning to designers that the main risk with BIM is the potential to start defining means and methods, which would lead to responsibility for site safety.  If a project arrangement has the design team participating and coordinating such data, the safety record of the construction manager/contractor and the quality of the subs becomes the paramount concern.

Finally, Damian Hamlin (Beck Group) demonstrated another use of Revit for a GSA courthouse expansion/renovation while Tracy Lee and Amy Kim of Orcutt Winslow and Dan Russell of Sundt Construction discussed their collaboration on a data center project for Blue Cross/Blue Shield of Arizona.  What made the Orcutt Winslow/Sundt presentation different was the fact that the project was based on design-bid-build, unlike most of the preceding presentations; however, the CM, electrical and mechanical sub-contractors were pre-selected due to the complex nature of a data center project.  Orcutt Winslow has been using Archicad for some time and continued its use on this project.  Of note was their finding that much of the intelligence within their Archicad models was not translated into Navisworks for use by the extended project team.  I wonder which method they were using to translate the data?

The main focus of the Orcutt Winslow/Sundt presentation seemed to be the benefits of the collaborative BIM process - owners, subs, engineers and designers all involved in design coordination meetings enabled quicker resolution of issues, subs gaining a better understanding of the design intent, and the design team better understanding construction techniques.


In closing, my evolved role as Senior Manager of Virtual Design + Construction at SOM has allowed me to focus more on our 'social' BIM aspirations.  We have completed a number of BIM-based projects, but we are currently reaching out to our construction management partners in an effort to enhance the overall design delivery process.  In contrast to other efforts within our industry the AGC BIMForum seems to be chugging along at full-steam to address difficult and complex issues.  Anyone can join the BIMForum and discuss the issues online or sign up to attend the next meeting at

Thursday, October 02, 2008

THE Revit Workstation

So, the 64-bit versions of Revit Architecture, Structure and MEP 2009 have been released - finally shattering the 4 GB RAM ceiling.  We're currently using workstations with 8GB of RAM, but I have a 'testing' machine with 16 GB of RAM (sweet!).  After installing the new Revit version, I opened the Freedom Tower model with all worksets on...yeah, I was feeling naughty.  Virtual Memory usage crept up to around 7 GB when I opened up a full 3D view, then...I rendered.  The VM didn't seem to change, but I didn't realize the rendering engine in 2009 runs in a separate process...ringing up another 5 GB of VM.  So, if 16 GB is barely going to cut it, I decided to price out a Dell T5400 with a 3.0GHz quad core Xeon with 32 GB of RAM and a 1.5 GB video card.

$11,516 ... nice.