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Specifications within BIM G#4394

By 11 November 2015February 23rd, 2016Daily Updates

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Specifications within BIM

Specifications within BIM

A conversation between 2 grey hairs (Specification Writers or Spekkies)

I was flicking through this month’s Journal to see yet another article wherein the author was explaining the virtues of BIM technology. With its data rich environment, 3D modeling, complete with specification, which I was pleased to see, as it means they still can’t get rid of it.

  • ‘Complete with specification’ = not a document anymore but data attached to objects
  • I wonder if the specification can be extracted as a single complete document?

He then tackled a new approach with BIM of customized searching ability which is just computer justification jargon since someone had to put the information in there for him to find.

  • They can’t get rid of us yet
  • No more Project Specs.
  • Just Product Specs from now on?
  • Project Specs are dead Long Live Product Specs

He then waxed lyrical about the mixture of all the stakeholders working on a single 3D model file

  • Such a big file that everybody has to upgrade their hardware, operating systems, RAM, software, broadband and tea breaks whilst the files open.

He then goes on to the Contractor peeling back the layers of information and discovers something in missing which immediately generates a Request For Information RFI. This indicates to me there has been no improvement in the provision of information with all the BIM applied.

  • If the spec is in the objects it can only carry the component products and materials information.
  • The assembly information comes from the drawings.
  • The fixings or mortar or glue lines has to be objects with their own spec attached
    • Processes feel unattached
    • Workmanship feels unattached
    • Tolerances feel unattached
    • Testing feels unattached
  • I often say a single line on a drawing can mean 5 processes, not easily attached to a space between objects.
  • British library floor thresholds under doors made by up to 7 trade contractors in many different permutations depending upon the floor finish and build ups, could be a BIM nightmare.
  • Does IFC have a ‘by which trade contractor’ cell?
  • Remember that RIBA stages have been changed to fit with modern procurement for the big projects and big practices and it is now useless for normal architects and normal projects (the vast majority of the profession?).

The Contractor still has the same attitude of ‘I won’t do it until someone tells me what it is and I will be paid extra money based on the number of RFI I have issued’, but still expects the Architect to provide it.  Thus maintaining the status quo.

  • Specific notes that the architect asked to be included in the spec, feel unattached.
  • Do BIM IFC COBie classification tables have an ‘extra notes’ cell.
  • When we do a really thorough spec, it avoids the need for so many RFIs
  • I don’t feel confident that our thorough approach to specification is accommodated.
  • Since NBS have been the stakeholders in BIM then the tables will be thin like NBS clauses.
  • NBS Create may have had to get better at thickening up the clauses.
  • But NBS approach (never mix prescriptive and performance in the same clause) prevents BIMers and us from being thorough in the specification to defend against substitution and so not RFI-free yet.
  • Under this regime we will all have to fit the confines of the BIM Spec straightjacket.

The BIM has fallen short of the expectation that the entire body protagonist claim for its wonderfulness.

  • I think it will fall short for a long time yet.

© HdeM & BrianSpecMan
11th November 2015

Specifications within BIM
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  • I have just read about a project where (they?) decided to do a BIM only project and all components were chosen because they had BIM files.
  • So now we specify stuff because its got BIM,
  • Its like choosing PVC windows because BRE Green Guide gave them an A rating and they are cheap.
  • And its like one architectural practice reported it would only specify a product if it was in NBS Plus
  • NBS will probably accept they have placed the specification well, in relationship to appropriate clauses
  • I doubt NBS would claim any competency judgement on their part.
  • Tail wagging the dog again

© GBE NGS ASWS BrianSpecMan aka Brian Murphy
12th November 2015 – 23rd February 2016

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