Coordination & Interference Checking

Coordination & Interference Checking


In this lesson, students will learn how to link models created by all members of the design team and use the Autodesk® Revit® software Coordination Review and Interference Check tools to find and resolve changes and conflicts.

Design teams using a BIM-based approach to coordinate their work can use coordination reviews and interference checking to find problems and resolve conflicts during the planning and design phases of the project lifecycle. This early review helps teams avoid costly mistakes and oversights that would otherwise surface much later during the field construction process.

BIM-based coordination also creates an opportunity to verify the geometry and dimensions of elements before they are placed in the field, and this facilitates the prefabrication of components, which can vastly improve the efficiency of the construction process.

Coordinating and Reviewing Model Changes

Link the Autodesk® Revit® Structure and Autodesk® Revit® MEP models created by other disciplines in the design team to find changes made to shared elements and decide how to act up on those changes.

When you link a Revit model, the software automatically looks for changes to any shared elements and recommends performing a coordination review if any are found. The coordination review reports:

  • The type of change found
  • The elements in both the host and linked model affected by the change
  • Recommended actions to resolve the change

Some changes can be resolved by choosing from the recommended actions in the Coordination Review dialog box. Other changes may require you to modify elements directly in your host project.

Checking for Interference Between Model Elements

You can also check for interferences and conflicts between model elements using the Interference Check tool.

You can use this tool in two ways, to:

  • Compare the locations of elements placed in a single model.
  • Compare elements in a host project to elements in a linked model.

Interference checking is very helpful for finding conflicts that might otherwise go unnoticed because the conflicting elements are not seen in the same view. It is good practice for design teams to do internal checks within each model, and also do pair-wise checks to look for conflicts between the elements placed in each linked model by the various disciplines.

Learning Objectives

After completing this lesson, you will be able to:

  • Understand the importance of performing periodic coordination review of models that have interdependencies.
  • Appreciate and apply the concept of coordination between models that contribute to the same project.
  • Assess the options available in and the limitations of automated Coordination Review for acting upon the conflicts.
  • Understand how to perform interference checking tests across different models, model categories, or particular selections.
  • Investigate a particular interference and take action to resolve by changing the location of one of the interfering elements.


Coordinating and Reviewing Model Changes

In this exercise, you will learn how to:

  • Link models from other disciplines to the architectural model.
  • Find changes made to shared model elements.
  • Act upon the changes reported in the coordination review.
  • View the integrated model with the changes resolved.

Figure 4.6.1 - Reviewing changes to shared elements in the coordination

Video Tutorial

Student Exercise
  • Open the model for this exercise in Autodesk Revit.
  • Link to the lighting model that was created in Autodesk Revit.
  • Run a coordination review to find the changes to shared elements that were made in the linked model.
  • Review and act on the messages reported in the Coordination Review dialog box.
  • Move the lighting fixtures in the architectural model to the new locations to match the MEP model.

Figure 4.6.2 - Coordination Review identifying differences in lighting fixture placement

Checking for Interference Between Model Elements

In this exercise, you will learn how to:

  • Link models to prepare for interference checking.
  • Set up and run an interference report.
  • Review the issues reported in the interference report and showing the intersecting elements.
  • Narrow the scope of the report by selection or by choosing specific elements to check.

Figure 4.6.3 - Highlighting intersecting ducts and joists found during an interference check

Video Tutorial
Student Exercise
  • Open the model for this exercise in Revit. This model includes the elements in the plumbing design with the architectural model already linked in.
  • Link to the HVAC model that was also created in Revit MEP.
  • Open a view of the area to be checked, and adjust its settings to feature the HVAC and plumbing elements.
  • Run an interference check to look for intersecting elements in the current project and the linked HVAC model.
  • Review the messages in the Interference Report dialog box.
  • Change the elevation of the sprinkler pipes that intersect with the ducts so that there is an appropriate clearance between these items.

Figure 4.6.4 -  Clash between a duct and sprinkler pipe in the plenum space {/sliders}


Checking for Interference Between Model Elements

  • What happens when you reject a change? Are the users of the linked models automatically notified? How can these changes get resolved?

If you reject a change, the originator of that change will be notified that the change was rejected during their next coordination review to the model. At this point, team members must communicate and agree upon the best resolution.

  • What strategies could you use for resolving elements that were copied into a linked model and changed there? Should you always delete these elements in your host model?

When copied elements have been changed, you must decide whether to retain ownership and control of those elements or, instead, to cede them to the team member who made the change. If you do the latter, you should delete or hide the original element in your host model and use the changed element from the linked model.

  • How can you share a coordination review report with others (or save it for your records)?

Coordination reviews can be saved as HTML reports and shared with other team members or archived.

Coordinating and Reviewing Model Changes

  • What are the advantages and disadvantages of comparing all elements in two models versus narrowing the scope of the check to compare fewer elements?

Running interference checks upon all the elements in two models typically detects more collisions than are practical to manage. For this reason, it is better practice to narrow the scope and compare fewer elements in each interference check.

  • What is the most efficient way to highlight the conflicting elements and make changes to them to resolve the interference?

From the interference report results, you can select an element and choose “Show” to highlight the element in the drawing area.

  • How can you update an interference report to remove issues that have already been resolved?

You can refresh the interference report to update the list of issues and filter out any issues that have already been resolved.

Key Terms

Key Term
Coordination Review
A tool that enables users to review warnings about changes to the monitored elements, communicate with other teams working on the same project, and resolve issues regarding changes to the building model.
Interference Check
A tool that finds intersections between elements in a project. These can be a set of selected elements or all elements in the model.
A spatial conflict or intersection between elements in the model.