Coordinate your Revit BIM Off
One of the major advantages in working with Autodesk® Revit® as a BIM tool is the ability to combine models from different disciplines and simulate the building before breaking ground. Coordination of all the disparate elements and systems in a modern building is a sizable task, although made much easier on the computer screen where elements don’t have a huge cost to change and iterations can be explored. Gone are the days when an architect can reasonably expect to turn over a set of 2D documents to a contractor and think the bulk of his or her job is done. Coordination in a virtual world is much easier, faster, and less expensive with reduced risk for the stakeholders including owners, contractors, engineers, and designers. The intention of this article is to cover some of the basics of BIM coordination. Any one of the topics could quickly become an in-depth examination of workflows, strategies, and differing pedagogy. Coordination starts with something overlooked yet extremely powerful.
Figure 1: Open your eyes
I find that people working consistently in a plan view hardly ever open a 3D view at the same time and this will lead to issues more often than not. Your model may look great at a cut line of 3’6”, but when switched to a 3D view, it completely falls apart above and below. This leads to bad documentation or even worse, modeling to documentation transitions. It’s amazing how little people actually understand about the model they are building. Remember we are modeling and we are not in a 2D world anymore! The primary focus of any Revit/BIM project is modeling; the documentation, good documentation, comes from a good model. Bad models get bad drawings. Work in a 3D view as much as possible, and augment that 3D view with a plan view of the same area of the model. This methodology will give you a better understanding of what is going on in the model.
Figure 2: You cannot see what you cannot see
When working with federated models—that is, models from different disciplines—keep the files loaded and visible in project while working. I suggest a workset for each linked model and creating a 3D view with the “View Graphics” set to isolate that particular workset only. The people working on the model are the first line of defense for finding what does not fit, is not functional, or is just out of whack. By not loading and having the other players’ models visible in your model you have a self-imposed blind spot. The more information quickly and easily available, the better the constant stream of decisions we make on our projects.
Things that you can’t see can hurt you.
Figure 3: Stud Rails modeled (since pipes don’t want to penetrate these zones)
Figure 4: Foundation surcharge illustrating no-dig zones
Figure 5: Door swing clash representations
As a building gets built there are numerous objects that are not seen by the naked eye, but are easily seen on the computer screen and useful for coordination and clash detection; some of these include Stud Rails at the top of columns, surcharge “no-dig zones” under footings, parking clearances, and even door swings. Many architects say that modeling or even considering such things is doing the contractors work for them. I vehemently disagree with this sentiment. Each and every problem in a building project needs to be solved—either by the use of intelligent decision making, or at the other end of the spectrum, at the wrong end of a gavel. The increased communication of the coordination process enables the resolution of these issues from large to small with input from the designer in keeping with your design intent.
Do you, as a designer, like to determine or influence the placement of a 4” sanitary down pipe or would you like a plumbing sub to place it in front of your $50 per s.f. Italian marble clad wall?
Communication
While we speak mostly of models drawings and clashes, it is good to not forget the importance of verbal communication. Many of the internal and external coordination issues can be solved with simple communication. The value of “tribal knowledge”—knowledge that a consistent team builds during the production of the project—can’t be overstated. Compared to 2D CAD-driven projects, BIM projects demand a high volume of communication driven by the large amounts of data created and managed. In 2D projects, vast amounts of information were assumed (fill in your own colloquialism). This can be easily demonstrated by looking at a set of plans hand drawn from 40 years ago and a contemporary set of drawings. Many things were left unresolved and consequently solved in the field either ad hoc or with an RFI (read: additional cost). As the scale, complexity of buildings, and regulatory oversight increase, the numbers of RFIs did so at almost a logarithmic rate.
Contractors Are NOT the Dark Side!
Modern BIM software has made the invisible visible and real. These items can be quantified, tracked, positioned, and scheduled with great precision and ease. As we move further into a BIM-enabled world good old-fashioned verbal communication skills can have huge positive effects on efficiency and results. Get the contractor and subs on board early and work WITH them—they are NOT “the dark side.”
As noted earlier, the days of turning over a set of plans to the contractor and being done are gone. The contractor and subs will be ultimately responsible for the construction of the building, with input from the designers and engineers. The cooperation of those experienced and knowledgeable professionals can help get a better building faster. On any sizable project, subcontractors will model for fabrication, sometimes even in Revit. The use of IFC makes it quite easy to integrate the subcontractor models into our Revit models to check for possible issues. Quite often, Autodesk Navisworks® is used for this, which can make the process even easier and automated once selection sets are created.
Coordination Meetings
I know… not another meeting.
I feel your pain.
But running a meeting online where everyone shares a screen and sees the same thing can be a powerful exercise in resolving issues. The data is apparent and visible, the decision makers are present, and issues can be quickly resolved.
The first level of coordination is visual.
Either in Revit or Navisworks, models can be quickly inspected in 3D with or without the use of sectioning. Many interferences, gaps, misalignments, and general model problems are easy to see.
The second level of coordination is computational.
Again, either with Revit or Navisworks, clash detection can be run to a very fine tolerance to find the less visible, obvious clashes. Some people use the term micro and macro in regards to clashes. To me this is a misnomer. Solutions to a seemingly small problem can have large effects on the building.
If we are working from the frame of the balancing act of producing the best building, at the least cost, for the greatest profit, coordination has to be an integral component of the process. Modern BIM software affords new levels of simulation in our built environment and one of the main components of that simulation is the coordination of disparate systems.
I find it humorous that we look at a weather simulation, aka forecast, every day to decide whether or not to take an umbrella to work, but architects still fight the notion that we are simulating a building so we don’t have sewer pipes in front of our prized facades.
A very special thank you goes out to Brian Moon and Kyle Spitznagel of Hathaway Dinwiddie Construction Co. for their cooperation, assistance, collaboration, and passion for Making BIM Better!
