Glossary - Clash Detection

Clash Detection

Source: Spatial

What is Clash Detection

A ‘clash’ is the result of two elements in your design taking up the same space. In Building Information Modeling (BIM), clash detection is the technique of identifying if, where, or how two parts of the building (e.g., plumbing, walls, etc.) interfere with one another.


1. Hard Clash:

Hard ClashSource: Spatial

Hard clashes occur when two or more components are occupying the same space or are interfering with each other. For instance, plumbing is routed through a wall or ductwork cutting across a steel beam.

Hard clash detection is conducted on the basis of geometry-based and rule-based algorithms that are embedded into the BIM object.

2. Soft Clash:

A soft clash indicates that an object has not been given sufficient geometric tolerances in the design phase or if its buffer zone has been violated. 

An example of a soft clash would be failing to leave sufficient space for maintenance workers to service an air conditioning unit. If the building design lacks sufficient space, it will trigger a soft clash.

To detect soft clashes, adequate object-related tolerance data must be provided to the BIM object based on the applicable building standards and regulations.

3. Workflow Clash:

While not an object clash, in BIM, a workflow clash results from inconsistent or conflicting building information. For example, an HVAC maintenance schedule that does not align with the scheduled delivery of spare parts.

Workflow clash detection (or 4D clash detection) identifies conflicts in equipment, material delivery, scheduling, and other timelines.

Sequenced timelines can be developed by inputting the start and end times of each activity.

How to Detect and Resolve Clashes

Detect Clash

Source: Spatial

Clash detectionin BIM is integral, especially as more governments around the world are starting to mandate it. The ability to detect all types of clashes is available in many BIM software programs, including Spatial’s BIM solution.

Once clashes are identified, they can be reviewed and resolved before advancing to the construction process.

What Is Clash Detection in BIM Used For?

BIM clash detection is an effective method for inspecting designs, identifying clashes, and preparing clash reports during the engineering and design stage. It helps:

  • Assess structural integrity
  • Assess energy efficiency
  • Reduce instances of human error
  • Prevent expensive late-stage redesign
  • Prevent scheduling clashes
  • Plan efficient building operation
  • Ensure compliance with regulatory requirements
  • Ensure the master model satisfies safety and performance requirements
  • And more

What is Building Information Modeling Software (BIM)?

The Building Information Modeling (BIM) process is a multi-disciplinary process to plan, design, construct and manage a building. BIM is used extensively in architecture, engineering, and construction projects (AEC)

Learn more about Spatial’s 3d modeling and 3d visualization BIM software.


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