National CAD Standard National CAD Standard The National CAD Standard (NCS) is a collaborative effort in the United States among computer-aided design (CAD) and building information modeling (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. Adoption of the NCS
CAD data exchange of describing geometry, both mathematically and structurally, there is always some loss of information when translating data from one CAD data format to another. One example is when the translation occurs between CAD systems using different geometric modeling kernels, in which the translation inconsistencies can lead to anomalies in the data. The intermediate file formats are also limited in what they can describe, and they can be interpreted differently by both the sending and receiving systems. It is, therefore, important when transferring data between systems to identify what needs to be translated. If only the 3D model is required for