I'm a little late to this post but take a look at SolveSpace, they have a native Linux client and it's free (GPLv3). The downside is you'll have to build it yourself. - Source: Reddit / 27 days ago
100% you made my day with this comment. I searched for the Maison Trouvaille and It's something incredible! Or wow, me too btw :) I'm just a cleaning manager, but I like everything connected to design. Did my first creations here https://planner5d.com/ They also have a design school course, so I'm thinking...Youtube, planner or to leave all these efforts and just enjoy the processes :). - Source: Reddit / about 1 month ago
If you like to try youtself as a designer for the cave - check this site https://planner5d.com/. - Source: Reddit / 6 days ago
FreeCAD - An open-source parametric 3D modeler
Sweet Home 3D - Sweet Home 3D is a free interior design application that helps to draw the plan of house, arrange furniture on it and visit the results in 3D.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
SketchUp - 3D for Everyone
Floorplanner - Floor plan interior design software. Design your house, home, room, apartment, kitchen, bathroom, bedroom, office or classroom online for free or sell real estate better with interactive 2D and 3D floorplans.
SolidWorks - Dassault Systèmes SolidWorks Corp. develops and markets 3D CAD design software, analysis software, and product data management software. SolidWorks is the leading supplier of 3D CAD product design engineering software.