Clash detection in Navisworks and Revizto is a standard part of most BIM coordination workflows. Teams run it on every complex project for good reason: it finds spatial conflicts before they become field problems. What it does not do is catch every problem in the model before work starts.

TLDR:

• Clash detection finds geometric conflicts in BIM; rework from missed clashes averages 5% of total project value.
• BIM software catches three clash types: hard, clearance, and duplicate. Sequencing and access conflicts require human judgment.
• Navisworks Manage is the most widely used tool; Revit handles within-model checks before full federation.
• Clash avoidance starts before models are federated. Teams that build it in run detection against cleaner models.
• Resolve puts the full model in front of specialty contractors and superintendents to surface issues clash detection was never built to find.

What Is Clash Detection in Construction?

Clash detection is the process of identifying spatial conflicts between building systems before construction begins. When a mechanical duct runs through a structural beam, or a plumbing run collides with a conduit, those are clashes. BIM clash detection software finds them by overlaying coordinated models from multiple trades and flagging intersections automatically.

The process is standard on most commercial projects today. Teams typically run clash detection in Navisworks, Revizto, or similar tools, generate a clash detection report, and work through issues in coordination meetings before work reaches the field.

The core value is straightforward: finding a conflict in a model costs far less to fix than finding it after steel is hung or MEP rough-in has started.

The Three Types of Clashes in BIM

BIM clash detection software categorizes conflicts into three distinct types, each requiring a different response from the coordination team.

Hard Clashes

Two building elements physically occupy the same space. A structural beam running through a duct is the classic example. These are the easiest to find and the most likely to cause immediate rework if missed.

Soft Clashes

Elements don't touch but violate required clearance tolerances. A pipe routed too close to electrical conduit for code-compliant maintenance access is a soft clash. Navisworks and Revit both support tolerance-based rules for catching these.

Workflow Clashes

Sequencing conflicts where two trades need the same space at the same time. No geometry overlaps, but the schedule creates a collision. Most clash detection software won't catch these without 4D simulation.

How the Clash Detection Process Works

The clash detection process follows a consistent sequence across most BIM workflows, regardless of which software handles the checking.

Teams begin by federating discipline-specific models, typically architectural, structural, and MEP, into a single coordinated file. In Navisworks, this is done by importing NWC or IFC exports from authoring tools like Revit. Once combined, users configure Clash Detective by selecting which model sets to test against each other, setting a tolerance value, and choosing a clash type: hard, clearance, or duplicate.

Running the test produces a clash detection report listing every conflict found, grouped by discipline pair. Teams then review, assign, and track each item through resolution.

Common Clash Types

There are three clash categories most software checks for:

• Hard clashes occur when two objects physically occupy the same space, such as a duct running through a beam.
• Clearance clashes flag objects within a defined buffer zone, catching maintenance access issues before they become field problems.
• Duplicate clashes identify geometry modeled more than once in the same location, often a sign of coordination errors between linked files.

The Business Case for Catching Clashes Before Construction

Industry estimates suggest rework costs average around 5% of total project value, and a large share trace back to coordination failures that clash detection could have caught earlier. According to FMI Corporation research, more than $177 billion is lost annually in the U.S. due to inefficiencies including rework. The math is straightforward: finding a conflict in a model costs almost nothing to fix. Finding it after concrete is poured or ductwork is hung costs multiples more in labor, materials, and schedule. The VR headset ROI for construction is just as compelling.

BIM clash detection has become standard practice on complex projects for exactly this reason. It moves the discovery of spatial conflicts from the field, where fixes are expensive, to the design phase, where changes are cheap.

Clash Detection Software: Tools the Industry Uses

Several tools dominate the clash detection conversation, each with a distinct role in how BIM coordination actually runs.

Navisworks

Autodesk Navisworks Manage is the most widely used clash detection tool in construction. Teams use its Clash Detective feature to run interference checks across aggregated NWD/NWC files, generate clash reports, and manage issue resolution workflows. Navisworks Simulate offers a lighter version of the same workflow. Navisworks Freedom is a free viewer but does not support clash detection.

Revit

Revit includes a built-in Interference Check for within-model clash detection. It works well for discipline-specific reviews but lacks the multi-model aggregation that Navisworks handles. Many teams run Revit checks first, then federate models in Navisworks for full-project coordination.

Cloud-Based Options

BIM 360 and Autodesk Construction Cloud ACC bring clash detection into a browser-based environment, making results accessible to more stakeholders without requiring local software installs. Revizto takes a similar approach, combining clash tracking with issue management in one connected workspace.

Reading and Acting on a Clash Detection Report

Clash detection reports come in several formats depending on the software used, but most follow the same basic structure. Each clash entry includes a clash ID, the two elements involved (for example, a duct and a beam), the clash type, the geometric coordinates of the conflict, and a status field that tracks review progress.

Teams typically sort clashes by discipline pair, severity, or status to work through reviews systematically. A Navisworks VR clash detection report might contain hundreds of entries, so filtering by grouping rules is standard practice before any coordination meeting.

Status Categories Worth Knowing

Most BIM clash detection software tracks each clash through a lifecycle:

• New: flagged but not yet reviewed by the team.
• Active: reviewed and confirmed as a real conflict requiring resolution.
• Reviewed: seen by the team but not yet assigned or resolved.
• Approved: accepted as a known condition or intentional design decision.
• Resolved: the underlying model has been updated and the clash no longer exists.

Keeping these statuses current is what separates a useful report from a noise document. Issue tracking through resolution is what prevents stale reports with hundreds of unreviewed "New" clashes from slowing coordination.

What Clash Detection Doesn't Catch

Geometry conflicts are only one layer of what can go wrong on a project. Clash detection tools do exactly what they say: they find where objects physically intersect. But several categories of problems fall completely outside that scope.

Sequencing conflicts, for example, won't show up in a clash report. If two systems are spatially clear but impossible to install in the planned order, no software flags that. BIM virtual reality opens a different layer of review that clash tools miss entirely. The same goes for access and maintainability. A pipe routed in a geometrically valid location may still be unreachable for a technician performing routine maintenance five years post-construction.

Construction tolerances, means and methods, and real-world site conditions don't live in the model either. VR design reviews for constructability surface constraints that 2D plans and clash reports cannot.

This is where broader coordination workflows matter. Getting the right people into the model earlier, including specialty contractors and field superintendents who understand sequencing and access constraints, surfaces issues that clash detection was never built to find.

Clash Detection vs. Clash Avoidance

Clash detection is a review step. Clash avoidance is a design discipline. The distinction matters because no amount of detection fixes a process where conflicts are being generated faster than they can be resolved.

Avoidance starts earlier, before models are federated for checking. It means setting shared spatial zoning rules so mechanical, electrical, and structural teams are working from agreed-upon routing corridors from the start. It means assigning clear model ownership per discipline so elements don't get duplicated or repositioned without coordination. It means giving teams federated access during authoring, at every stage instead of only at review milestones, so conflicts surface before they compound. Specialty contractor BIM coordination depends on exactly this kind of early involvement.

Teams that build avoidance into their process still run clash detection. They just run it against cleaner models. Real-time project collaboration at the coordination meeting means faster resolution, less noise in the report, and more time spent on the issues that genuinely require trade partner judgment, not simple geometry fixes.

Beyond Clash Detection: Where Resolve Fits

Clash detection finds geometric conflicts. It does not catch the ones that matter most to the people building the work.

A pipe that clears a beam by 200mm passes every clash test. A superintendent who needs to run conduit through that same corridor, account for insulation, maintain code clearances, and sequence trades in the right order sees something completely different. That gap is where field problems live.

Resolve puts the full model in front of the people who understand those constraints, before work begins. Specialty contractors, superintendents, and trade partners can walk the space, raise issues, and pressure-test sequencing without a BIM specialist mediating every question. See how this plays out in a data center Navisworks VR case study.

Clash Detection: Tools and Workflows

Running clash detection is a good habit, but your coordination process is only as strong as the people reviewing the model. Geometry conflicts are the easy part. Sequencing, access, and constructability issues require field expertise that most BIM reviews never actually include. get your whole team in the model, so the people who understand those constraints can weigh in before work starts.

FAQ

What is clash detection in BIM and what types of conflicts does it catch?

Clash detection in BIM is the process of overlaying coordinated discipline models to automatically flag spatial conflicts before construction begins. BIM clash detection software identifies three categories: hard clashes (two elements physically occupying the same space), soft clashes (elements violating required clearance tolerances), and workflow clashes (sequencing conflicts where trades compete for the same space). Most clash detection software handles hard and soft clashes well; workflow clashes typically require 4D simulation to surface.

Clash detection in Navisworks , Revizto, and Revit: Which should my team use?

Navisworks Manage is the better choice for full-project coordination because it federates models from multiple disciplines into a single file and runs Clash Detective across all of them. Revit's built-in Interference Check works for within-model reviews but stops short of multi-model aggregation. Most teams run Revit checks first at the discipline level, then federate in Navisworks for project-wide clash detection reports. Revizto is another option worth considering: it combines clash tracking with issue management in a single connected workspace, making it a good fit for teams that want coordination and resolution in one place without switching between separate tools.

How do I keep a clash detection report from becoming noise my team ignores?

Keep clash statuses current. A Navisworks clash detection report with hundreds of unreviewed "New" entries makes it nearly impossible to track real coordination progress. Assign each clash a status (Active, Reviewed, Approved, or Resolved), filter by discipline pair before coordination meetings, and close out items as models are updated. The report should reflect where the project actually stands, not where it stood three weeks ago.

What issues will clash detection software miss on a complex MEP project?

Clash detection software finds geometric conflicts. It does not catch sequencing problems, inaccessible equipment, construction tolerances, means-and-methods issues, safety hazards, security vulnerabilities, or other real-life use issues that require an expert's eye. A pipe that clears every clearance rule in Navisworks may still be unreachable for a technician performing maintenance after handover, or positioned in a way that creates a safety risk no geometry check would flag. Getting specialty contractors and field superintendents into the model early, before work is locked in, surfaces the coordination failures that a clash detection report was never built to find.

Can Resolve replace clash detection tools on my project?

Resolve can surface clashes when team members walk the federated model, but that is not its primary use case. Dedicated clash detection tools like Navisworks Manage and Revizto specialize in running interference checks and generating clash reports at scale. Resolve sits downstream of that workflow, giving superintendents, trade partners, and owner-side staff the ability to walk the space at human scale, raise issues in context, and pressure-test sequencing and access constraints that automated clash detection cannot flag. The tools solve different problems on the same project, and most teams use both.