DWG

DWG is AutoCAD’s native file format, and its name comes from the word “drawing”. A DWG file stores lines, arcs, text and dimensions, along with layers, blocks, external reference links and sheet layouts prepared for printing. It can hold 3D geometry as well.

Why it is so common

Technical drawing in architecture and engineering has long been done largely in AutoCAD, so DWG has become a shared language between disciplines. Architectural drawings, structural and services drawings, survey base maps and setting-out sheets regularly travel in this format. Many other CAD and BIM programs can read and write DWG files too. DXF, a text-based exchange format, is used to share data with programs that cannot open DWG directly.

What to watch in practice

The DWG format has gone through several versions over time, and a file saved in a newer version may not open in older software. When sharing drawings, saving to an earlier version that suits the recipient’s program is a common habit. Before sending a file for 3D modeling or rendering, purging unused layers and blocks and binding external references speeds things up. A messy DWG can cost hours at the modeling stage. We explain which files to prepare and how in our article on files needed for architectural rendering.