cost of a clash

An intelligent building information model enables us to virtually fail and then coordinate the building systems. After the interference check is run, instances of colliding beams, pipes and mechanical equipment can be resolved with the input of the architect, engineers and subcontractors. All of this can be done without setting a foot on the job site.

Without BIM, subcontractors attempt coordination
independently of each other and then run into problems in the field.

An example of a clash is an
8" PVC pipe colliding with a W8 x 28:











This particular clash comes from Togar Suites, one of Tocci's jobs in Union, NJ. It is one of 20 that was found in the ground level of the 400,000 sf project.

With the help of Stephen Burkholder of SR Enterprises, I was able to figure out what BIM saved us in this particular instance.

If this clash wasn't detected ahead of time, the following costs would have been associated with it:
  • $1300 (the cost of a W8 x 28)
  • $2500 (the cost of a W24 x 55 to replace it)
  • $205 (removing the beam with a crane - if the beam had to be removed by hand, the cost would have been $356)
  • $195 (installing the new beam with a crane - if the beam had been installed by hand, the cost would have been $705)
  • $464 (the cost of cutting the hole for the penetration in the field)
Those costs don't even include other concerns with replacing and cutting the beam in the field:
  • An analysis of the beams is required to detemine if shoring would be required
  • Structural systems status (is the W8 x 28 supporting anything that will need to be supported or replaced)
  • Field penetrations are typically required after erection is completed, causing delays to other trades such as
    • Spray on fire proofing
    • Finish work
Since the clash was detected prior to steel fabrication, the only costs associated with it were:
  • $2500 (the cost of a W24 x 55)
  • $210 (the cost of cutting the hole for the penetration in the shop)
Which would an owner rather spend on one beam:

$4932 or $2935

1 comment:

Andrew said...

And of course this also doesn't take into account the additional time taken, and the potentially disastrous knock-on effects in the project schedule...