There is one type of BIM, that I call the Bully BIM.
It is a bit of a ‘below-the-belt punch’ kind of BIM
approach.
It is called ‘Clash Detection’.
At its essence, it is a well-intended concept.
Unforeseen clashes of building elements cause a lot of
trouble when discovered during construction and subsequently slow progress
down, result in abortive works, extra materials, labor cost and lengthened programs.
Using technology to eliminate (or at least minimize) such issues on the construction
site makes sense.
And it doesn’t. At its premise is the idea, that following
semi-independent work done by many consultants (in model-base or otherwise) an
automated procedure identifies the clashes of spatially conflicting elements
and highlights them.
But in practice, it is an ignorant and arrogant approach,
used to gain points over something or someone and rarely works to the benefit
of the project.
It is ignorant as it ignores the reality of design
definition development in contemporary construction projects being continuous through
to the completion of the building.
There are no fully designed/modelled projects that can be
effective clash-detected.
There might be really well designed and modelled projects
that everyone worked together throughout the design process and the resulting
model is ready to be built from.
In those rare cases automated clash detection ‘interventions’
will add little value, so why bother.
And then, there are the majority of the cases where clash
detections is forced onto partially defined-partially documented projects and
the outputs are reports going into hundreds of pages of ‘issues-needing to be
looked after and dealt with’.
Those reports shoot the entire BIM movement in its foot
and make building modelling as a field look dumb.
Yes, building services should be well designed and
coordinated before everyone hits the site and scrambles for their place within
the zone allowed.
Sure, major dramas happen when there just isn’t enough
space within ceilings, ducts and risers for everything that needs to be put
there.
But clash detections aren’t there to find these major dramas,
they are done, to score brownie points for a clash detector.
It is extremely likely that those major dramas, even if
picked up will be buried so deeply within Clash Detection Reports that will be
lost in the sea on insignificant ‘move the pipe 25mm to the left’ – responses and
stay unresolved. (meanwhile many hours are spent on managing the administration
of ‘issues’)
Paying a lot of money for someone to clash detect a model
created by someone else is counter productive.
Paying someone a lot of money for someone to model
someone else’s design, so it can be clash detected is even worse.
Over the years, I wrote regularly on this topic.
So, being Easter and a time for various games, let me
propose one here:
Go through my blogposts (595 including this one) and find
the number of times I mentioned ‘clash detection’ in them. Put the number down
here in the comments.
The author of the closest number posted before the end of
April (Midnight NZ time on the 30th April) will win an A3 sized,
hand made mosaic of their chosen portrait picture.
For examples, see here:
Do I believe, people will take on this game? Nah.
So, let’s add that, the number needs to be within +/- 5
to qualify.
If no one enters I’ll just carry on with my current
mosaic project.