Posted: 27.09.2016

Clash detection is one of the most popular BIM requirements that we come across on projects.

This post will examine the relevance of clash detection to project participants, additional posts will make recommendations about extra information that can be added to a clash detection report, in order to make it more useful for everyone.


Demand/Pull Side (clients and contractors)

Clash detection is the most commonly requested objective we’ve come across when working on a BIM project. For clients, a clash detection report shows them the tangible benefits of BIM, where coordination issues have been caught and fixed before getting to site.

Contractors are interested in clash detection and resolution for similar reasons, many are also keen on using the reports as a performance metric.







If you’re a contractor and you want to do this, please bear in mind that you will probably not see a nice smooth reduction in clashes, you will see spikes every time a new discipline’s model is added to the exercise.

Right: Whoops! Some steelwork is blocking these doors.


Supply/Push Side (designers, consultants, subcontractors)

There are also internal benefits to using clash detection. Even when no BIM requirements exists on a project we will often internally combine models and use them to identify issues.

We have found it much faster to either perform a visual analysis of federated models by compiling everyone’s data together in a BIM authoring system, or by using dedicated analysis applications such as Solibri Model Checker.


Time spent printing and then checking rafts of construction drawings is no longer required, or at least greatly reduced.

It is also easier to identify vertical or multi-storey issues, which 2D drawings can sometimes be ineffective in communicating.

Left: Models from separate disciplines combined for clash checking.


A word of warning

Successful coordination and placement of everyone’s data is essential for accurate clash detection.

Please see my previous posts on coordination for help on this.