Navisworks: From Design to Construction and Back

January 9th, 2012

Training BIM Integration Between Teams

A common question in the AEC industry is “where does design end and construction begin?”  The AGC BIM Forum concluded that the truth is that they both occur together until the project ends; however, the degree of change varies.  In order to help better facilitate the changes that occur during construction, the design team and project team can benefit tremendously by being trained on BIM technologies.

Figure 1: Construction and Design relationship

Training to Identify True Issues

A good practice, while coordinating all the different disciplines in a building, is to first concentrate on the large issues that will require design changes.  These issues are typically structural issues and ceiling issues.  These issues should be honed in on right away as they will require the design team and project team to coordinate ideas into an effective solution.

A quick way to use Navisworks to identify steel issues is to set up standard batches with mechanical, electrical, plumbing, and fire protection against steel.  A quick method to know roughly how many clashes you need to set up for the project is to use the combination formula: K!/(N!(K-N)!) where K is the number of models and N is the number you are comparing at the same time.  Thus if you have a project with AMEPSF and you clash 2 at a time the formula is 6!/(2!(6-2)!) which means at a minimum you should have 15 clash sets.

Rather than concentrate on each minor hit, use the tools in the results tab to isolate large occurrences of clashes.  Training on these tools should be from a working professional who has seen these tools work well and also seen their failures. 

A major clash could be a pipe that is running through multiple steel beams in a row.  Identify the issue not the clash.  It is important that the team understands the difference between an issue and a clash.  The difference is that an issue documents the real scope of the problem and encapsulates multiple clashes; a clash is simply a hit of two triangles in two different models. It’s important to note that, Navisworks is tessellated software, meaning that each face is merely a representation of multiple triangles connected together and that a clash is simply when two triangles are passing through one another. 

Once and issue is identified you should use the redline tools to capture the scope of the problem for downstream review and tracking.  Using the redline tools has the added benefit of anchoring the image.  This means that if you click the clash that the issue was identified on and navigate away from the view, you can click back on the clash and be taken back to the redlined view.

On the construction of the Newport Beach Civic Center & Park, a $105 million project that is currently in progress for the City of Newport Beach,  C.W. Driver’s construction management team identified a number of different issues that needed to be resolved by the project team as well as by the design team.  One of the issues involved beam penetration for fire protection.  Because of the high level of development of the models, the C.W. Driver team was able to identify long runs of fire sprinkler pipe that collided with steel.  By identifying the entire scope as it was, rather than tens of individual hits, the team was able to grasp the entire problem.  It was found that the fire protection penetrations were not properly mapped out.  Because the steel was being fully pre-fabricated, including all beam penetrations, identifying and resolving this issue was critical to control cost and time impacts.  Once identified, it was a simple matter to correct the penetrations before beams were manufactured saving time and money.

Figure 2: Newport Beach Civic Center & Park Fire Steel Issue

To find ceiling issues in the model, use the find items tool and search for all the ceilings in the model.  You can click on a ceiling in the model and review its properties to learn its name and type.  Then setting the search up is as simple as using keywords with “or” conditions attached, common words are “act,” “ceiling,” and “hard lid.”  Set up the MEPFS clashes, and use the results dimming tools and highlighting tools to identify the issues.

Project Teams Issue Resolution

After issues have been identified, the project team should meet together and review the issues.  During this meeting, it is key that each trade is present to review the issues and help come up with possible solutions.  During this time, it is important that the team is trained on the measurement tool.  Navisworks Freedom 2012 allows the use of the measuring tool in the model.  A common use of this tool during these meetings is to find the elevation of an object.  The problem is that the base of an object, such as the bottom of duct work, is shown on the plans referenced to the nearest finished floor.  In Navisworks, the object is based upon the location in 3D space.  This means that the ductwork previously mentioned might have the bottom of the duct at 30’ according to the measuring tool.  To overcome this, simply use the point-to-point tool.  Click the bottom of the duct and the top of the finished floor.  In the delta section of this tool, the z column reveals the actual height of the duct.

Figure 3: Measuring Tools

Using the measuring tool the team should assess whether there is an alternative method of installing the item.  If no other routing can be taken, the issue must be taken to the design team.  At this point, the project team should assign responsibility.  To document this properly, you can use the tag tool in the review tab of the ribbon.  This tag is searchable and can easily be tracked and referenced.

The Design Team

Once an issue has been identified by the BIM Coordinator and reviewed by the project team, it may require the attention of the design team.  These issues vary in their impacts to the project.  Some issues may be small, such as a relocation of a fixture, but some issues are larger, such as the changing of steel configurations and ceiling heights.

If an issue is large and requires a significant design change, it is important that the project team has all of the information assembled before the review begins.  This helps the design team understand the full severity of the issue.  To do this, the project team should create all the viewpoints necessary ahead of time to view the issue and all of its impacts.  Viewpoints can save hidden object overrides, as well as color overrides, if you change the global option settings.  Change them by clicking the application button, expanding the interface, and clicking viewpoint defaults.  With these powerful tools, you can save special viewpoints tailored to the issues you wish to cover with the project team.

During the review with the design team, many solutions will be discussed amongst participants.  It is helpful to have the construction documents available to review as the model portrays the offending issue.

On the Newport Beach Civic Center & Park project a few large issues came to light while coordinating the project.  Karolina Kaczmarczyk with BCJ, the project’s Architect, has seen the value that BIM has added to the project. Karolina says, “Our team has greatly valued our experience with BIM on the Newport Beach Civic Center & Park project. On a project this large and complex, it is extremely challenging to discover every conflict throughout the design process. Meeting regularly with the construction team and MEP trades while using the BIM platform to resolve issues has enabled the team to work with greater coordination, reducing the number of change orders. BIM has brought clarity to the process, and the team is confident that the end result will meet the clients expectations, if not exceed them. “Being able to seamlessly coordinate with all trades concurrently allows us to reiterate and remind the project team about the design intent. As a result, this has proven that the team is now finding better solutions for moving a pipe or rerouting a duct before asking to move a wall or lower a ceiling. We recognize that catching potential problems early on has not only improved the construction process, but has also strengthened our relationships with our clients and project team. When everyone shares a vision it can only lead to a strong design and an intelligent building.”

Figure 4: Team Vision

Implementation of Changes

For coordination to have any lasting effects each team must be trained on changes.  The common method is for the project team to submit an RFI and await a response from the architect for how to proceed.  Training must occur in the BIM coordination environment, so each party understands its responsibilities.

Any change directed by an RFI must be made to the model by the parties involved.  For example, this means if there is a ceiling change, it is the Architect’s responsibility to ensure that the architectural model is updated.  Likewise, if any other discipline is changed it is that discipline’s responsibility to update their model.  These updates are important to discover how the change will impact the rest of the project.

Once the models are updated, the project coordinator must understand how to re-run the clashes and ensure that the issue was resolved.  This is more than simply clicking the re-run button in clash detection.  A model audit must become a standard. One of the first checks to be made is to know whether or not the larger RFIs have been written.  If the workflow of tagging issues has been followed, a simple search with the search tool will reveal all of the RFIs that have been tagged in the model. 

To search for all RFIs, simply click the search comments tool from the review tab of the ribbon.  In the search field simply type in a search string.  You can use wild card characters to enhance your searching capabilities such as *RFI*.  This will generate a quick report for you to use to check to see if the correct party has submitted a required RFI.

Figure 5: RFI Search

The next audit on the model is to see if the offending geometry was corrected.  This is done by the BIM Coordinator by re-running the clash detective and reviewing the results.

Because coordination is an iterative process the model will take time to become fully coordinated.  Below is a change shown in the Newport Beach Civic Center & Park project.  There was an issue regarding the location of the plumbing utility lines around numerous electrical duct banks.  This issue involved the plumbing subcontractor (Pan Pacific), the electrical subcontractor (Rosendin Electric), the Architect (BCJ), and the civil engineer (ARUP).  All of these parties had to come together to review solutions to not only meet code, but to ensure that the future owners of the building could properly maintain the utilities.  In the end, the transition between the start of coordination was made as shown below.

Figure 6: New Scope and Coordination

Handling New Scope

During the course of an active coordination, new scope often will be added to a trade.  The issue arises when new scope is added to an already coordinated area.  How does the team handle the new scope and continue to finish coordination on the new areas?

When situations like these arise it is important that the project team and design team has the training required to deal with these situations.  Wherever the new scope was added, the affected parties must make the necessary changes the same as they would in a RFI environment.  The difference is, when new scope is added, clashes will be re-run.  Any new issues must be identified if any exist.  Where new issues do exist, they need to be documented as new issues and be clouded on any existing signed off documents.  The issues must then be fully re-coordinated.

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About the Authors

Michael Smith

Michael Smith

Michael N. Smith is a BIM Manager for C.W. Driver, a large general contractor in Southern California. The firm is highly regarded throughout the design and construction industry for implementation of BIM innovations on each project and for creating customized software plug-ins to increase the efficiency of the latest software releases.  Michael is also a guest author and technical editor of Mastering Navisworks 2012.  He can be reached at msmith@cwdriver.com.