The great challenge for architectural modelers, is to import and manage cad files into Blender with ease. To achieve this result one addon come to our rescue.
DXF-importer imports DXF files into Blender-3D. Its developed for both 2.49 and 2.63 (Work in progress,See the website for details on the development).
There is also a DXF-importer developed simultaneously with the standard importer, it’s called DXF-importer Personal Edition and you can obtain it by registering through mail into its site.
This importer has a huge amount of features that are absent in the standard version, it’s developed by Remigiusz Fiedler and in this page you can follow the development and register for the download: http://www.cad4arch.com/dxf_importer/
From the author site:
DXF-importer PE (Personal Edition) is a new version of importer developed in sync with CADtools project. In compare to the standard version delivered with Blender it is faster and supports projects of any largeness and complexity.
Configuration panel of the importer offers big number of options and you should invest some time to learn the proper usage of them. With proper configuration you can significantly reduce import times and data volume. The importer can read DXF data of any complexity. Even corrupted / broken DXF files can be handled properly.