Opun Planner - Opun Planner is a free and web based design planner for all kind of interior designing requirements.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
Ecdesign - Ecdesign.
FreeCAD - An open-source parametric 3D modeler
Minutesmatter - One of the greatest advantages of using this interior decorating and designing software is that it allows its users to get the curated selection of features and functions.
SketchUp - 3D for Everyone