Have You Tried It? Clash Management

Clash management, the process of identifying and resolving spatial conflicts between building elements in a BIM model, is necessary for successful construction project delivery. Since the advent of Navisworks and virtual coordination, BIM departments have circled this concept of establishing better clash management practices to communicate and quickly resolve clashes before they hit the site. 

Not all clashes are an issue! But we'll get to this later...

As projects become increasingly complicated, with ambitious designs paired with crunched timelines, BIM departments and their onsite counterparts have sought new ways to improve the coordination process. One such way is to break the traditional waterfall approach to coordination. Historically, onsite teams wait until coordination is complete before breaking ground or, more realistically, skip it altogether—if time does not allow. 

Now, with adaptable technology and the ingenuity of project teams, coordination can be grouped and prioritized into sections—like running coordination for the interior of a project while teams build the exterior. 


Remember when I said, "Not all clashes are an issue?" There's a difference between seeing a clash and needing to do something with that clash. Clashes are not all created equal. There are some clashes where one clashing object just isn't going to move anywhere, like structural designs. Additionally, some objects are never actual clashes on-site, and there are clashes that specific teams can ignore. 

A priority system must be enshrined regarding what types of clashes need to be addressed (fungible vs. detrimental), at what point a set of clashes needs to be addressed, and what clashes will never be addressed, or excluded altogether. This activity is what we consider "clash management."

Many Hands Make Light Work

At this point, let’s review Autodesk's philosophy on clash management: Many hands make light work. Coordination is possibly the most effective way to stave off unalterable and costly downstream mistakes. You may be asking then, "Why not put more people towards the task and create a low barrier of entry clash detection tool?” This is precisely why we created our Automatic Clash Detection tool in Autodesk BIM Collaborate. 

By clashing everything without setup and without the need for specialized expertise, more people can jump into coordination during their part of a construction project, making early design, detailing, and construction coordination possible whenever.

Find the needle, throw out the haystack

However, this clashing method alone is insufficient to run highly effective coordination programs. Too much noise in the system makes it nearly impossible to find the clashes that are the most important to resolve. Finding the clashes each team needs to fix requires a set of rules and filters, some fixed, some dynamic, that help individuals hone in on relevant clashes and quickly resolve them. 

Let's take a break from the abstract and talk about details. On day one of coordination, a few decisions need to be made: 

  1. Is there going to be a time when I don't need to see clash information? 
  2. Do I have project partners who only need to see specific objects in their clash results (e.g., MEP and interiors or structural and architectural objects)? 
  3. Do I want to break down my coordination program into phases (from major concern clashes to detailed clashes or by building)? 
  4. Finally, how detailed do I want to get to in my coordination program? 

Once you answer these questions, you can apply simple rules for anyone in your project to jump into coordination and use clash detection in a way that makes sense to them.

Here are a few tools in Autodesk BIM Collaborate to help you accomplish this:

Turn Models Off/On

Certain models are never really going to need to be clashed, especially in certain phases of the project. For many, opting out of the architectural model from clash detection is an easy way to remove unnecessary noise. 

Object Exclusions

Remember when I talked about creating coordination steps or phases to tackle the most critical concerns first? Object Exclusions, a tool for clash detection, lets BIM Managers do just this. They can select models and the objects in those models to filter out objects they never want to see clashed during that phase. Then, once complete, they can turn off the exclusion rules and move to the next set of rules. 

This way of stepping through coordination, with a pragmatic exclusion path, is so effective. In fact, customers have asked for ways to scale these rules to more of their projects. Based on that advice, we created the ability to import an exclusion rule into any project. 

Clash On/Off

One of the simplest ways to remove noise and get the information you need faster is to turn off clash detection for coordination spaces altogether. By doing this, a BIM team can utilize all the model aggregation, Issue Management, spatial alignment, and design review capabilities in Autodesk Construction Cloud without engaging the clash engine. Teams who choose this route can even use the direct connection between Navisworks and Autodesk Construction Cloud to run clash on the desktop while collaborating on the web.

Filter by Views

Finally, creating custom views to filter clash results is a personalized way to address the clashes that matter most to you. By combining models and breaking them down using standard or advanced filter rules, anyone can see just the clashes that are relevant to them on the clash matrix. These “Views” can be saved and reused at any point, providing a solid overview of where they are in their design, in the coordination of designs, and where the project is on its path to being ready for onsite construction. 

These tools are just a sampling of capabilities Autodesk is working on to make your own work and partnering with others easier. Clash management is both a project-wide endeavor and a personal approach to understanding which clashes need extra attention. But our mission to democratize clash detection for all, to help individuals make impactful decisions, does not change. It is reinforced by these tools now at your disposal. 

Want to learn more about clash management? Join me for The Powerfully Simple Navisworks + ACC webinar on April 17, 2024, at 10:30am MDT. Register for the webinar:


Kyle Seyler

Kyle Seyler is the Senior Product Marketing Manager at Autodesk Construction Cloud. A seasoned product marketing leader with over a decade of experience in go-to-market strategy, Kyle harnesses the power of marketing to connect with diverse industries, from adventure travel and winemaking to manufacturing and construction. During his 5-year tenure at Autodesk, he has developed programs that equip educators with engaging curricula for the future of manufacturing. He currently leads a team of product marketing professionals committed to addressing the construction industry's challenges through intelligent yet simple technology.