Estimating, Digitally

     As an estimator, my profession can be most simply summarized by the following:

                                              “I change a picture into a number”

  While there is a lot more nuance to it than that, the simplicity of that statement is accurate (in my humble estimation). I take a drawing, perform a takeoff, and convert that data into labor hours, vendor quotes, and RFI’s. This has been the standard for plan-spec construction projects since long before I came along. Recently, however, an emergent tool has been introduced, Building Information Modeling (BIM).

  For those unfamiliar, BIM is a relatively new construction tool that takes the standard construction plan, and turns it into a digital 3-dimensional rendering. Depending on the level of development, this rendering can provide a rough conceptual representation, or be physically accurate to a quarter of an inch, detailing exact utility routing, footing depth, architectural feature dimensions, unitary dimensions, and mounting characteristics/locations.

  Today I was engaged in a conversation regarding bid strategies, and one of the sticking points of that conversation was the process of a takeoff. Plans that are scaled (shame on you engineers that do not scale your drawings) are easy to perform takeoffs on, especially with programs like Blubeam, and the myriad of online takeoff tools that bid-boards tout. There are two inherent problem with those programs however, in that the drawings often require further clarification due to errors or omissions, and the programs themselves are not equipped to generate takeoffs on the more detailed design criteria (delegated structural design, for example). These are some of the nuances that an estimator must anticipate, and account for.

                                                     The question is, why?

  If the use of BIM (think LOD 300+) enables the building owner to not only know, within extraordinary tolerance, the exact building characteristics (not to mention performance and maintenance data), then why is it that we need to rely on the nuances? BIM as we know it is widely implemented after the bid phase, requiring coordination between all trades (think tedious and often argumentative meetings) and before construction (save yourself a headache, and don’t implement it during). That seems counter intuitive. At present, I have the ability to digitally render a piece of duct, section of pipe, or custom fastener, and send that rendering to a vendor for manufacturing. Why are we not doing this before the bid phase on new building construction?

  From a construction management standpoint, if a digital rendering of the entire structure and utility characteristics has already been generated and properly layered by trade, my expectation of change orders has vanished. From an estimator standpoint, if I can export all of my required parts and pieces to my manufacturers for quoting, then a full takeoff as we know it is largely unnecessary. Finally, as an owner, I can rest easy knowing that my seemingly large investment up-front, has ultimately saved me a substantial sum in subcontractor costs, as the parts and pieces are all accounted for.

  I would love to see an BIM engineering firm that encompasses multiple disciplines, and utilizes industry construction experts to check for build-feasibility (just because it fits on paper, doesn’t mean you can build it). The potential for streamlining the construction schedule, while saving in construction costs by developing and implementing a BIM coordination plan prior to bid phase, is enormous.

                                                      Again, in my humble estimation. 

If you would like to know more about Building Information Modeling, I recommend the article by Erin Green:

And the TED talk given by Phil Bernstein:

https://www.youtube.com/watch?v=Kg0gbG1DAkk