AEC Tech News #151

13 Sep, 2005 By: Michael Dakan

Cadalyst AEC Tech News

Standards in the News

Bentley Licenses the National CAD Standard;
GSA Looks to BIM and IFCs

NIBS (National Institute of Building Sciences) announced on Tuesday that Bentley Systems, developer of MicroStation software, has become the first CAD developer to license the NCS (National CAD Standard) in order to incorporate it into its software. Bentley will write a plug-in for MicroStation that incorporates the AIA (American Institute of Architects) CAD Layer Guidelines, the CSI (Construction Specifications Institute) Drawing Symbols and Terms and Abbreviations portions of the NCS.
NIBS had issued an open Invitation to Participate to CAD developers when it announced the licensing program early this year, and Bentley becomes the first developer to announce plans to participate, which is very good news for MicroStation users. We hope that other CAD developers also decide to participate, because the best way to ensure widespread use of a common CAD standard is to build it into the software, making it as easy as possible for CAD users to comply. As long as the CAD standard resides only in an expensive, multivolume set of books sitting on a shelf, widespread compliance will be difficult to achieve.
Bentley?s approach to making the standard an optional plug-in also makes a lot of sense. The United States has the National CAD Standard, which has also been partially adopted in other parts of the world, but many areas and jurisdictions support a different set of standards. Plug-ins imply that another standard could be implemented in a similar way.
NIBS has also updated its NCS Web site and seems to be keeping it current with new developments and announcements, which is a good sign of more active promotion and support of the NCS. NCS v3.1 was released early this year and is available for purchase on the Web site. The cost remains $350 per copy to the general public and $250 for members of the organizations that contributed to the creation of the compiled set of standards. However, the relatively high price of an individual copy becomes less significant when it?s rolled into your CAD program for automatic use.
The CAD developer-licensing program is a very good move by NIBS, assuming the license cost is reasonable and more CAD developers get on board. The previous major effort of the NCS organization to achieve widespread adoption by getting building owners and their groups to require the use of the NCS, while somewhat effective in promulgating the use of the standard, caused some resentment and only a grudging acceptance by many of those forced to use it. Making it seamless and easy to use by building it into CAD programs is a much better way to achieve widespread compliance.

GSA to Require BIM Data for Design Review
On another standards front, the U.S. GSA (General Services Administration) has targeted fiscal year 2006 to begin the use of BIM (building information modeling) based on the International Alliance for Interoperability?s IFCs (Industry Foundation Classes) for preliminary design information. The GSA typically is responsible for more than $10 billion annually in federal building construction and is a major client for many building design professionals
The use of BIM should make review of projects proposed for construction by the U.S. federal government easier and more accurate. Data models constructed in compliance with the aecXML data schema can more easily be linked to programs for cost estimating, scheduling, energy use and other critical tasks.
NIBS has taken on the leadership role in developing the National CAD Standard and the work of the IAI in developing the IFCs and the aecXML data schema. This should result in closer collaboration among the groups developing these important initiatives in the AEC industries.
Some people seem to be under the impression that IFCs will make the NCS less important. Each effort does relate to data interoperability within AEC industries, but each is really aimed at different aspects of the problem of file and information exchange. The IFCs and aecXML define a data model for 3D/4D CAD information to make it easier and more efficient to use the data for many related purposes in a building lifecycle. The NCS is aimed more at the graphical appearance and use of CAD data primarily when producing 2D construction documentation.
Although it may be true that the widespread use of BIM in AEC may one day make the National CAD Standard less relevant, we are still a long way from that day. Building construction documents will still be published in 2D on paper and electronically for many years into the future, while BIM continues to mature and gain the capabilities and universal use that help it supplant the traditional uses of 2D CAD publication.

ISO Approves PDF/Archive Proposed Standard
The ISO (International Standards Organization) this week approved the PDF/A (PDF/Archive) proposed standard for archiving electronic documents.  PDF/A is a subset of the complete, current Adobe PDF format, and was developed to ensure long-term preservation and availability of archived digital information. Long after the software program used to create the PDF/A document becomes obsolete, the developing organizations are committed to ensuring that the data will still be available.
Now known as ISO Standard 19005-1, the PDF/A format was developed by an ISO committee of affected user communities to define a critically important international standard for long-term storage and retrieval of electronic documents. In development since 2002 ? an exceptionally short period of time to achieve ISO approval ? PDF/A joins PDF/X, a previously approved ISO standard for the print industry, as an PDF-based ISO standard. Other PDF-based standard file formats are in development, which will further solidify that format as a multipurpose, multiplatform file format for long-term use in many industries.

Michael Dakan is an author and independent CAD and information technology consultant. E-mail him at

what's new at
For an online version of this newsletter as well as past issues
of AEC Tech News, go to

Get the Code!: Cadalyst's Hot Tip Harry and AutoLISP Solutions code for September is now available for download from Cadalyst?s Web site.

Cadalyst Labs Review -Architectural Land Desktop: Autodesk's latest version of its venerable program for civil engineers is updated for AutoCAD 2006. 

Cadfidential : Each month, Cadalyst magazine takes a behind-the-scenes look at the CAD world.