Want to get the most collaboration out of your BIM Team? These recommendations, based on many years in the BIM trenches, will help your BIM coordination efforts run more smoothly.
Getting the Models the Way You Need Them
Have each discipline that uses Revit create a specific 3D view called “3D BIM Coordination” using the “Duplicate View” command. Hide all elements that have no relevance to 3D model coordination (movable furniture layouts, grid lines, and so on). This will assist in keeping the file sizes as small as possible and make the models less confusing. Make sure all section boxes in the “3D BIM Coordination” view are hidden. This view, once set up properly, will contain the correct visibility settings you wish to export and will be always set up for future model version updates.
If a discipline does not have the appropriate 3D object that represents a specific component of their model, have them use a 3D “placeholder” shape in the form of a cylinder, sphere, cube, or rectangular object to indicate your element, making sure it is the same general shape and physical size as the actual object. This placeholder can be replaced later by the specific component or element.
What’s in a Name: Establishing Element Naming Guidelines
Each discipline should be requested to name model elements and components based on a logical system agreed upon by the BIM Team. A BIM project is a 3D data base from which meaningful information is to be extracted and sorted.
Get a sample list of element family naming conventions from all disciplines to be used to compile a master Element Naming Guidelines document for the team. Whatever naming convention is chosen, it should be descriptive, logical, structured, and consistent. Create unique short names, using natural language that describes how the object is identified in the real world and include the general class of object or the family category as the first part of the file name. When you mouse over an object in Autodesk® Navisworks with “Quick Properties” turned on, you should be able to know precisely what the object is in the Item Name tag that pops up.
Maintenance or Serviceability Zones consist of clear space necessary for maintenance and repair access in front of electrical or equipment panels, ceiling access panels with clear space above and free space below, or access to valves. Indicate equipment (pumps, valves, VAV boxes, etc.) accessibility areas with rectangular massing objects that go from the floor to the ceiling or in front of access panels.
“No-fly Zones” consist of spaces above electrical and equipment rooms that need to be clear of trades other than electrical to accommodate the copious conduit runs necessary or space below roof access openings that should be clear of any system elements. Indicate No-fly Zones and Maintenance Zones with semi-transparent rectangular massing objects next to their respective element(s).
“Crop circles” objects indicate approved distances by the structural engineer between locations of anchors attached to decking used to fasten hangers. Crop circles cannot overlap and can be modeled using flat cylinders.
Major equipment with ducting or piping that travel overhead or through walls may need to be modeled (stoves with hoods and exhausts, boilers, overhead cabinet seismic bracing, and the like.). Also, turning radii for wheelchair access can be indicated by red 5’ diameter semi-transparent cylinders.
Don’t Double Up
Doubling up on model geometry must be avoided. Have BIM Team members include in their models only the elements checked below for their discipline. Architects and structural engineers will duplicate or use the same model for most of the structure; architects and plumbing disciplines often model their own version of plumbing fixtures. Resolve between disciplines the elements that should be contributed in each discipline’s model in order to eliminate elements that could create duplicate clashes or confusing results.
Create a chart like the one below, indicating all elements to be modeled, and then share it with the Team. The elements listed below are often disputed, but choose only one discipline to contribute these elements for the Consolidated Model.
Examine each discipline’s model to look for obvious errors and omitted elements such as “floaters” (floating objects that are too low or high) and “disconnects” (elements such as pipe or duct lines that are not connected), along with making sure drain and waste pipes are sloping. Disciplines should be encouraged to do their own internal clash detection and to coordinate with each other, behind the scenes, so that coordination meetings take less time.
To communicate to the disciplines where floaters and disconnects are located, create a Viewpoint that is zoomed into a floater or disconnect and redline each issue with a circle and place them in a dated folder called “mm_dd_yy Floaters and Disconnects” in the Saved Viewpoints window.
Create a Key Plan
A clash test “key plan” is the best way to see all issues on a relevant story and is a helpful visual summary for each established test. This top view will reveal the “nests of clashes” that comprise issues needing to be resolved.
Redline each issue with ovals and name them accordingly with a number along with the grid line closest to the issue: “1 @ A-5.” Export this image as a JPG and save it into the “Clash Reports” folder in the relative week’s Coordination Folder. Continue creating key plans for each established test.
Grouping Clashes into Issues
Think “issues,” not clashes. Issues are the problem areas we ultimately need to resolve. An issue is often made up of several clashes in close proximity. To discover conflict issues, select an area around a grouping or “nest” of clashes using a rectangular Select Box from the Select/Arrow. This is best done from the top view in the 3D Scene View. The “Select Filter” assists in isolating only the clashes that involve the items you've selected in the 3D Scene View.
Make this issue a Group and name the Group folder based on the issues identified in the key plans made above and indicate the closest grid lines; for example, “1 @ A-5.”
Organized Viewpoints as Interactive Clash Reports
Viewpoints are the best way to visually summarize the issues we have isolated in order to communicate to other stakeholders or members of our design team. Consider all the potential reviewers of the BIM Team’s work. Create and redline Viewpoints so that someone who was not a part of the meeting would know what you are trying to communicate.
Create a dated folder for each week in the “Saved Viewpoints” palette (Example: 01-13-12 Coordination Meeting). Within the BIM Coordination folder, create a folder for each test (e.g., Plumb-Elect, Mech-Elect, etc.) Name each Viewpoint the same as the corresponding Group name you gave each issue in Clash Detective, e.g., 1@A-5. Viewpoints redlined and notated can also be reviewed by others using the free Navisworks Freedom viewer or printed out and distributed to detailers, especially to those who do not have Navisworks Manage.
As an alternative to comments or tags, put abbreviated instructions on what to do as part of the Viewpoint name. The big advantage is that these instructions can then be seen in the Freedom file by anyone reviewing the work of the BIM Team.
When issues get resolved, rename each Viewpoint by placing RESOLVED in bold letters in front of each Viewpoint name. This makes it easy to see what issues are resolved and what issues are still open. Each issue that gets resolved is a “mini win” that is OK to shout out in bold.
Maintain a Viewpoint trail. Don’t overwrite the old Viewpoints with every new report. Keep them in their dated folders as a history of the coordination process, allowing the Team and other stakeholders to see at a glance how far you have come. Don’t create clash reports and simply say, “Here you guys go; see you next week.” Assign measureable tasks to make progress and hold all Team members accountable for their results.
Come Fly with Me
Load Navisworks Freedom on all stakeholders’ computers to facilitate having as many eyes as possible flying through on the Consolidated Model. Encourage members of the design team to review the Consolidated Model during design meetings, along with traditional 2D paper drawings. Meet with maintenance staff to show where items to be accessed are, with ceilings transparent and using Search Sets to help in navigation. To make it easier for non-technical people to navigate through the model, create a folder called “Rooms” to store Viewpoints named for each room. Navisworks is good at finding collisions, but cannot find design issues. Only trained professionals can.
John Stebbins is the Director of Operations for Douglas Pancake Architects in Newport Beach, California. Since 2008, his BIM projects total over $1.3 billion, specializing in BIM facilitation, BIM execution planning, and 3D BIM constructability modeling. John teaches BIM classes in the University of Southern California's Construction Management Department and Orange Coast College's Architecture program. Since 1988, John has been a leader in transitioning the building industry to BIM technology. He has given countless lectures and seminars, as well as led user groups and organized workshops throughout California and Arizona on the subject of virtual design and construction and the power of BIM.