There was a download of PartyCAD 12.2 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The program is included in Photo & Graphics Tools. We recommend checking the downloaded files with any free antivirus. The most popular version among the program users is 12.2. This program is a product of Point of Rental Software. The common filenames for the program's installer are PartyCAD12.exe or partycad7.exe etc.
From the developer:
With PartyCAD you can design nearly any event—parties, banquets, conventions, fairs, and meeting rooms. The program can also be used to design residential and business interiors, computer rooms, stage sets and most other spaces.
PartyCAD can do pipe & drape work, too, and can make lists of the parts needed to build your finished designs.
You may want to check out more software, such as FRED Optical Engineering Software, which might be similar to PartyCAD.