The US National CAD Standard and Why It Matters
According to the Wikipedia, “the National CAD Standard (NCS) is a collaborative effort in the United States along…CAD and … BIM users. Its goal is to create a unified approach to the creation of building design data. Development of the NCS is open to all building professionals in a collaborative process led by the buildingSMART Alliance.
The NCS is composed of CAD layer guidelines from the American Institute of Architects, uniform drawing system modules from the Construction Specifications Institute, and BIM implementation and plotting guidelines from the National Institute of Building Sciences.”
While adoption of the NCS is voluntary, any company that has adopted it can require its use by their associates. If your company adheres to the NCS and you plan to outsource any drafting or conversion services, it’s important that you make sure the CAD service provider you use is knowledgeable about the standards and willing to adhere to them on the work it does for your company.
Why NCS Matters
NCS provides a recognized continuity on file naming, issue noting and floor numbering that is critical to creating, archiving and recalling the correct sheet from the sheet set. This is vitally important in critical situations, because it eliminates confusion, ensures that the most current drawing revision is immediately available and can help reduce the expense of transferring building data from design applications to facility management applications.
For instance, if a vital communications system goes down, and you’re the contractor called upon to repair it. You’re on site, pulling up the drawing on your iPad to find the broken equipment or cable only to find that the cable is not where it’s supposed to be. That’s when you learn that installation company rehabbed the system months ago, but the facilities drawings were never updated. Following NCS prevents scenarios like this.
NCS V6 UDS Sections are also recommended for BIM implementation. In NCS V6 UDS Module 5: Terms and Abbreviations, there are over 2600 terms used in buildings, including new communications terms.
Here’s how these terms and abbreviation standards can help:
For instance, in the NCS abbreviations “TPAN” stands for touch panel—a touchscreen remote control used with a teleconference system, while “SRC” stands for the source of the teleconference signal. Without the NCS standards, different contractors may have represented these items differently, for instance just “T” or “S” and you would have to figure out what that means.
Triangles are often used for telephone and data ports, but NCS V6 says: “Symbols are graphic representations of objects, line types or materials.” Symbols, in other words, should be simple representations of complex technology, and can be standard shapes or may resemble the equipment or materials. In earlier NCS versions, there was some confusion about port symbology. In NCS V6, 48 new AV and communications symbols were added that follow the ANSI J-STD710 standard, which agrees with the BICSI and TIA symbols for ports:
- Data port triangles are filled, open triangles are a phone, a split triangle with one side filled is a data and phone port, whereas a split unfilled triangle is a miscellaneous port. See Figure 1 for examples of different NCS V6 ports and Figure 2 for a possible solution for this scenario.
- Many of the symbols look like what they represent (e.g., screens, projectors, speakers).
- Each symbol has attributes defining mounting, technology and a legend reference number.
- There is a clear side legend which follows NCS UDS guidelines which shows the legend number, the symbol and a short description of each.
If you’re following NCS protocol, make sure anyone you subcontract or outsource to does also. And, when you outsource make sure its a USA-based company if you want to adhere to US NCS.