National Institute for Building Sciences Standards

The National CAD Standard and the National Building Information Model Standard

Did you ever work in an office when a north arrow design competition was underway? I have to confess that I worked in a few such offices when I was an architectural intern. Of course this was in the old manual drafting days, and every once in a while someone would suggest that the office standard north arrow was lame. The next thing you know, a design competition was underway.

We may see a new round of the old north arrow competitions in offices after version 4 of the U.S. NCS (National CAD Standard) is released, because it appears that the new version will make it explicitly clear that the north arrow shown in previous versions of the NCS was intended as an example only, and the north arrow a company uses is strictly user-defined. It seems that many firms have developed a north arrow symbol that is part of their corporate identity, by similarity to a logo graphic or other means, and they are reluctant to give up their own north arrow. So, the sky is the limit. Live it up.

Work on NCS v4 is well underway, and I have been monitoring it on the Web site. A lot of discussions are going on about items proposed as changes, mostly of a refinement or clarification nature.

Several layer name changes and additions are proposed for information not foreseen in previous CAD Layer Guidelines. Among the desired changes are to clarify and make intuitive some layer names previously published in the AIA CAD Layer Guidelines. Most all of these are relatively minor changes.

Text heights also have garnered some rethinking -- the same old arguments about the standard 3/32” recommended height with some folks arguing for 1/8” for drawings that are most likely to be published by plotting to half-size. This item, as proposed, was rejected and didn’t get as far as a final ballot item.

Process and Procedures

The process currently used to process proposed changes is more formal and seems better organized than in the past, with multiple steps built in to the process. A task team subcommittee that specializes in certain aspects of the NCS reviews proposed items first before they get to the full committee for consideration.

The appropriate comments and actions at certain stages of the process are a bit confusing. The current period is still dealing with task team review and actions, and full committee voting on individual items is some time in the future (currently scheduled for January or February 2007). So there’s time to get involved and make your preferences known. The New Items Submission period was scheduled to close on August 10, but plenty of items are pending that you may feel strongly about. You can make your feelings known and vote on the items that will be incorporated in NCS v4 by going to the project collaboration Web site.

National Building Information Model Standard

While a separate task team of the National CAD Standard working group for BIM (building information modeling) exists, this group seems fairly inactive -- perhaps because of the separate formation of the NBIMS (National Building Information Model Standard) by the NIBS (National Institute of Building Standards). NIBS is the umbrella organization under whose auspices the work of the National CAD Standard, IAI (International Alliance for Interoperability) and others proceeds, as well as the National Building Information Model Standard.

With everyone operating under the same umbrella group, coordination and cooperation between agencies and groups should not be a problem. The NCS group and the NBIMS have some overlapping interest areas, but I suspect that the NCS will continue to deal primarily with the graphic representation issues of the BIM model, while the NBIMS deals primarily with the data associated with the model.

The NBIMS Committee has been fairly low-key about their efforts to date, but they have announced their intention to publish the first edition of the NBIMS before the end of 2006. So work is proceeding. For the first edition of NBIMS, they will undoubtedly rely on previous work from the IAI and other groups, and the first edition will likely include previously published documents, similar to the first edition of the NCS, which incorporated the AIA CAD Layer Guidelines, the CSI Uniform Drawing System and the U.S. Coast Guard’s Plotting Guidelines.

Also like the first edition of the NCS at this stage of development, they haven’t begun to do much publicity and attempt to get widespread adoption and support of the NBIMS. We can expect that to change as they get closed to having a product ready to publish some documents and as more organizations adopt the standard.

To learn more about NBIMS or to get involved, click here. To download a PDF file of an information paper, click here.