I have been using BIM on projects since 1998 and from these experiences I have created a list of best practices that I follow when collaborating between different design team members. This article, based on a presentation I gave with Erleen Hatfield at Autodesk University, is a collection of some of those best practices that can help ensure a successful BIM project.
Note: The definition of a successful BIM project is one that delivers a good quality product and one that is profitable.
Part 1: Managing Expectations
Establishing and understanding expectations from each design team member
A successful Autodesk® Revit® project goes beyond knowing the technical side of BIM software. There are important topics that need to be considered at the beginning of each project, long before the first element is even modeled. Some of these important topics and questions are listed below.
Revit models contain extensive amounts of rich and intelligent data, and the use and application of these Revit models are virtually endless. Therefore, it is extremely important to establish boundaries for the Revit models with the architect, owner, and contractor. This means that you will need to come to some understanding and agreement of the expectations among team members for what the Revit model contains and what it is to be used for.
Critical questions to ask at the beginning of each project:
- What is the intended use of the Revit model?
Coming to an agreement on the use of the Revit model with the architect, owner, and contractor will establish how much modeling effort there needs to be. Is the Revit model to be used just for architectural and structural coordination, or are there other disciplines involved in the 3D coordination effort? Will the Revit model be part of the deliverable as a contract document in which the contractor uses it to build from?
- What must be submitted at each phase of the project?
Is the Revit model expected to be delivered with the 2D drawings at schematic design? What about at development design and construction document phases?
- Between the architect and the structural engineer, who is modeling what?
The architect, structural engineer, and other design team members will need to come to an understanding about who is modeling which elements in each of their respective models. This could be done by a checklist that simply lists all the elements on the project and then assigning an element to each design team member.
Bear in mind that some elements overlap and more than one design team member may want to model these elements; floor slabs, for example. This checklist will also help establish who is ultimately responsible for the size and location of the elements in the 3D models.
- Are the management, organization, and exchange of the architectural and structural Revit models planned in advance?
A well-planned program between the architect, structural engineer, and other design professionals that establishes how each model is organized and how each Revit model will be exchanged will help the coordination process and eventually create a well-coordinated set of 2D documents.
Part 2: Coordination
What software are your clients/consultants using?
The ideal model setup for coordination is for each consultant to use Revit. At the outset of a project, it would be best to identify what software each design team member intends to use so that any problems with interoperability can be foreseen.
During the course of a project, upgrades or changes to the version of a software package can occur. It is best practice to allow for this when dealing with consultants who might not want to upgrade to newer software.
If a design team member is still using something as basic as 2D CAD, it is still perfectly feasible to make use of this kind of information in a Revit model, either as background linework or as lines upon which to trace particular items using some of the native tools for items such as grids, levels, walls, and beams.
The easiest way to coordinate
The easiest way to achieve efficient coordination is to get all of the design team to agree on a logical structure for the Revit model. This could be achieved via a BIM standards project. Creating project standards for items such as the software in use, file naming, sheet naming, and so on, can go a long way in creating a more efficient environment for the coordination efforts on a large job. This also results in a well-coordinated set of documents between all the design consultants, as shown in Figure 1.
Establishing ownership of items such as gridlines or levels, for example, can really help because the responsibility is maintained by one member. To extend this level of accuracy, using Revit’s tools for copy/monitor or clash detection, the other design team members can maintain the same geometry without any errors.
Figure 1: Examples of structural and architectural coordinated sheets.
How can this be recorded?
When working on very large Revit models that may be set up with Worksharing or Worksets, it is a very good practice to include comments when performing a “Save to Central” so that at particular times the model can be saved to another copy or rolled back if necessary.
Another method to record the evolution of the Revit model is to use reporting tools within Revit to save html reports of the interferences in the model. These can be useful to send to consultants to communicate where potential clashes are occurring. The consultant can then use tools such as “Select by ID” to find the pertinent members in the model.
Coordinating with non-Revit design team members
For very large Revit models, the combination of all discipline’s models may require Autodesk® Navisworks. The use of such software can make it easier to clash check and visualize very large or complex models, especially if some of the design team members are not using the Revit platform.
One of the many useful tools that Revit has for coordination in conditions where a multi-platform BIM is in effect is the use of the 3d DWF file which is a very lightweight file that can be emailed if necessary.
Revit is able to batch export 2D or 3D CAD files from the model. This can make it very easy to work with non-Revit consultants that require DWG or DGN files for coordination. The export of such files is very streamlined and should be tailored to suit the standard layer and linetype setup for the company CAD standards.
Dealing with Changes
Copy Monitor makes it extremely efficient to modify the design to match new geometry or design options. Setting up the Revit model to look for the latest linked models can make reloading the latest version of consultant’s models simple and efficient. This can be done easily in Revit and basically involves using the “Manage Links” tool to point the linked model at the latest version of a consultant’s model.
Note: Copy Monitor only works on five elements: beams, walls, slabs, grids, and levels.
When working with a new model from a consultant, it is definitely a best practice to utilize whatever new grids or levels have been created or modified in their model. These items are the cornerstones of BIM and should be maintained accurately, which is very easy to do if using Copy Monitor.
Who owns what? The new area of BIM contracts
With BIM technology maturing, new issues are appearing. One of these involves the determination of who owns the final Revit model. Deciding who will be ultimately responsible for the complete model at the conclusion of a project, or who will be maintaining as-built models for the project, will help avoid repeat work or unnecessary survey work.
Other decisions that are critical to efficiency are items such as whether the fabricator or detailer will be working from the model. Also, the consequences of sharing the digital model with the contractor could have a positive influence on the communication of the design and execution on site.
These issues should be covered in the contracts for BIM projects so that lines are set up for each member of the design team. Our office sets all this language in the terms and conditions of each contract and it is also referenced in the general notes of the contract documents.
Summary of Methods for Well-Coordinated Documents in Revit
- Set up linked views that show only specific elements and control this with view templates in each design team’s Revit model. This way, when the models are linked there no extra elements showing.
- Consider project size before linking/importing.
- The modeler should be aware of the frequency of revisions (weekly, bi-weekly?) of the other models.
- Origin (0,0,0) should be maintained throughout all design team members’ drawings. This is much more crucial than in 2D drawings.
- The standard organization can work for smaller projects, but custom organization may be necessary for larger, more complex projects.
- Customize for intuitive understanding for others who may work on the model.
- Use “Project Parameters” and apply to Views for custom organization (e.g., “For Reference Only” or a separation of “Perspective” and “Orthographic” for 3D views may be necessary).
- Keep in mind that copy/monitoring elements depends on the project and that there is no absolute standard.
- Consider the fact that the party responsible for the geometry (e.g., slab outline - architect) may be different than the party responsible for its properties (e.g., slab thickness and reinforcement – engineer).
- Coordination Review can be used only after copy/monitoring is set up and there will even be an automatic notification.
- Create/save the HTML Coordination Review Report once Coordination Review is completed, then export to Excel format. Excel allows better organization and manipulation of data.
- Identify the person responsible for the “actions” (manager or modeler). Do not ignore the “add comments” option for recordkeeping purposes.
- Exporting to AutoCAD® is useful for design team members who do not use Revit.
- 2D DWF may work better than 2D PDF for simpler viewing and printing.
- When exporting to 3D DWG, check the level of detail (e.g., Coarse, Medium & Fine). Structural members in fine detail show even the fillet radius adding additional geometry that may not be necessary.
- 3D ADT exporting from Revit may not recognize all Revit objects such as foundations and coping of structural members.
Hopefully, after reading this article you have picked up some useful tips on how to effectively and efficiently collaborate between the different design team members. There are too many tips to list them all here. Good luck, and I hope all of you have successful, productive, well delivered, and profitable BIM projects.
Marcello Sgambelluri is the BIM Director at John A. Martin & Associates Structural Engineers in Los Angeles, CA. He has been using Autodesk products for more than 15 years including AutoCAD, 3ds Max, and Revit Structure. Marcello teaches classes regularly at Autodesk University that focus on free-form modeling in Revit and he beta tests the year releases of Revit Structure. He can be reached at email@example.com.