Clash Detection

Management Summary

Clash detection is a procedure for detecting geometrical collisions between model elements of different disciplines and BIM models. It is an automated process where two or more models can be checked for these collisions using specified rules and tolerances. Clash detection is an integral component of the BIM process. It improves coordination between disciplines and has the overall effect of reducing costs and mistakes in a project.

Use Case Definition

This procedure is an important step in the BIM collaboration process. Having multiple designers working on different models leaves room for error, where different elements can clash, meaning at least part of one element collides with another at the same location or that certain tolerances are exceeded. These clashes can be checked automatically through tools using models and clash detection rules as input. These rules are created for determining what kind of object collisions will be understood to be clashes as well as any tolerances an element has. After the program automatically checks two or more models against each other for clashes, designers or coordinators have to go through them and confirm if they are indeed clashes and find a solution to fix them.

Aim and scope

The proposed use case aims to perform clash detection analysis between BIM models in an automated, rule-based manner.


Clash detection should have the overall effect of:

  • Saving time by quickly performing the task
  • Ensuring the compatibility between models and disciplines
  • Keeping a project on schedule by preventing avoidable delays in both the design and construction phase of a project by catching mistakes early on
  • Saving time in communicating clashes through issue management tools


Individual clashes detected by the program must be analyzed manually by the designer who must decide if each one is relevant. The clashes will need to be fixed by the responsible designers.


IFC: Industry Foundation Class

Project Group

  • Marcin Grzelak,
  • Christopher Kowal,



The documents reflect the current best practice and do not claim to be complete. They should not to be understood in the sense of a generally valid recommendation or guideline from a legal point of view. The documents are intended to support appointing and appointed parties in the application of the BIM method. The documents must be adapted to the specific project requirements in each case. The examples listed do not claim to be complete. Its information is based on findings from practical experience and is accordingly to be understood as best practice and not universally applicable. Since we are in a phase in which definitions are only emerging, the publisher cannot guarantee the correctness of individual contents.

Logo BIM Speed
  • Document Type : Use Case
  • GUID : 3F62144A-BB77-4C8D-A4D3-6BB14296B938
  • Identifier : BIMSpeed_UC15_MOW
  • Life Cycle Stage : ISO 22263
  • Revision : -
  • Project Status : Approved
  • Maturity level : Outlook
  • Use Case: In Progress
  • Processes: In Progress
  • ER: In Progress
  • Published on: Aug 31, 2022
  • Last change: Sep 1, 2022
  • Publisher: BIM Speed
  • Author: Grzelak, Marcin | Kowal, Chris Kowal

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