BIM and the NCS

If the relationship between the U.S. National CAD Standard (NCS) and the Building Information Model (BIM) was ever in doubt before, it shouldn’t be any longer. Proponents of the NCS have long-maintained that those using AutoDesk Revit, Bentley Architecture, and other CAD platforms geared towards the BIM should implement the NCS. They reason that the NCS provides a single standard for printed output (construction drawings) generated by BIM software. A single standard is certainly a good argument, but many CAD users have been reluctant to adopt a standard like the NCS while trying to incorporate the BIM into their workplace. However, since the recent release of Version 1.0 (Part 1) of the National BIM Standard (NBIMS), motivation to include the NCS as an integral part of the BIM has been dramatically improved.

When the National Institute of Building Sciences (NIBS) released Part 1 of the NBIMS, many NCS users were interested to learn the standard includes a requirement that states, "Graphical Information. Since all drawing[s] should at this point be National CAD Standard compliant we are making this a requirement for a minimum BIM. This demonstrates that standards are being considered when possible."

To reinforce this requirement, the NBIMS also includes a "Capability Maturity Model to Define a Minimum BIM." This model is a workbook that establishes a point system (credits) for various categories in order to determine five levels of BIM compliancy (Minimum, Certified, Silver, Gold, and Platinum). The "Graphical Information" category of the model assigns points according to levels of intelligent graphics and NCS compliancy (the Capability Maturity Model Workbook is a spreadsheet that may be downloaded at http://www.facilityinformationcouncil.org/bim/pdfs/BIM_CMM_v1.8.xls)

In addition to providing benefits for printed output, the NCS also establishes file-naming standards. As stated in the NBIMS, the "NCS contains a great deal of information about file management, location, and naming." The requirements for NCS model file naming are established in Module 01, Drawing Set Organization, of the Construction Specification Institute’s Uniform Drawing System (UDS).

With regard to CAD layers the NBIMS states, "NCS contains the CAD Layer Guidelines. Layers are a way to isolate or differentiate between objects in some packages. Future NCS versions may describe object isolation and differentiation in additional ways." The requirements for NCS CAD layers are established in the American Institute of Architects (AIA) CAD Layer Guidelines.

As architects and engineers incorporate the BIM into their workplace, they should anticipate that many of their future projects will be designed according to criterion established in the NBIMS. They should also be aware that between 2007 and 2009, minimum BIM requirements will increase each year. Therefore, as a tool to help users comply with the NBIMS, adoption of the NCS will become even more critical. Investing time to implement the NCS into the workplace sooner, rather than later, will certainly streamline the process for anyone that intends to pursue BIM.

For more information about the NBIMS, please visit www.facilityinformationcouncil.org/bim. For more information about the NCS, please visit http://www.nationalcadstandard.org/