A file with .nwd extension is a CAD file by Autodesk for Navisworks files that is a 3D model review software for architecture, engineering, and construction. NWD files combine design and construction data into a single model. This allows to identify and resolve differences and interference problems before the construction starts using the software. NWD files store model, environment, current view and saved viewpoints (include redlines, comments, etc.) information. These can also contain user-specified metadata in published form. NWD files can be opened in any Navisworks product and the Navisworkds Freedom viewer.
NWD File Format
NWD is Autodesk’s proprietary file format and that is why its details are not available. An NWD file can be thought of as the current state of the model. It contains all geometry information along with review markups for elaboration of view points. NWD files are 80% smaller in size due to compression of data as compared to the original size.