Daily Archives: May 4, 2009

BIM and Electrical Estimating

Several people have asked me about BIM lately. For those of you not familiar with BIM, it is an acronym for Building Information Modeling. According to Wikipedia, “Building Information Modeling (BIM) is the process of generating and managing building data during its life cycle. Typically it uses three-dimensional, real-time, dynamic building modeling software to increase productivity in building design and construction. The process produces the Building Information Model (also abbreviated BIM), which encompasses building geometry, spatial relationships, geographic information, and quantities and properties of building components”.

In some ways, this is a digital product similar to the physical models we used to have available for building oil refineries. If you needed to see how a conduit is routed, or solve a space conflict, look at the model.

To electrical contractors, this means that a three dimensional computer model will be available that shows all of the electrical work as it will actually be installed. Furthermore, estimators will be able to extract this information as the counts and measurements needed to prepare an estimate.

Do I believe this technology will have a major impact on the way most electrical estimators do business? Not likely. The principal reason I feel this way is that in my experience, and in the experience of most of my customers, the quality of  bid documents has been declining for many years. It seems unlikely that electrical engineers would be willing to incur the additional expenses required to create a 3D model on hard bid, competitive projects.

Second, in my 28 years of estimating, I have never been able to obtain a CAD file for estimating purposes (To be fair, CAD has not been a major factor for 28 years, but you get the point). In my opinion, this is because they do not want any liability for quantities of materials. If they are not willing to to give us 2 dimensional files, why should things be any different for 3 dimensional files.

The third point is in regards to the diagrammatic nature of electrical drawings. Unlike the refinery models mentioned above, today’s electrical documents do not show us exactly where to install materials. Most specifications point out that the drawing are diagrammatic, and require the electrical contractor take responsibility for installation locations. Again, I believe it is unlikely that 3D models showing electrical installations will be available for most electrical estimates.

BIM is however, making advances into the electrical contracting industry. Some of the larger electrical contractors are using BIM on design assist projects and for constructability reviews. We are also beginning to see contractual requirements involving BIM. There is a great article in the March issue of EC&M. The link is below. I am interested in your opinions, so let me know what you think.

EC&M Article Link – http://ecmweb.com/market_trends/industry_lags_bim_adoption_0301/