We have found one software suitable in our database for this conversion.
Chief Architect program has default support for DWG/DXF export so you can simply use the File ► Export ► Export Current View (DWG, DXF) option to export .plan files as .dwg drawings, which is what plan to dwg conversion typically represents.
Updated: January 24, 2022
PLAN
Files with plan extension are designs saved in Chief Architect program. The program is used for architectural home design.
DWG
A dwg file extension is used for common CAD file format, originally used by AutoCAD. A DWG is a proprietary format and can only be created in AutoCAD. Other CAD programs can usually import it, but not create its proprietary form. It's because of this, that DWGs are often exported to DXF interchange format, so they can be seamlessly used in other CAD programs.