Sweet Home 3D

This is a great and simple software, which runs flawlessly on Linux. It is just straight forward. the best thing I liked in this software is that you design everything on a 2D plan, and on the spot, the software creates a 3D image, which you can rotate, zoom in and out..etc.
It does not need any time to learn, as the controls are just in the right place.
I got to design 2 rooms in less than 30 minutes after just installing the software. Basic 3D shapes are available on source forge, and the software just points you to the library.
installing on linux is straight forward. just download, unzip, and run the .sh file.
Enjoy!
Thanks

It's the easiest program I've found (I have no CAD experience). But it's limited, and it's open source (at least in terms of models/plugins/textures) so they're only as good and extensive as what's being made. I haven't found the current iteration buggy at all: in fact, it works surprisingly well for freeware this complex. That said, the developer is very helpful--often on the forums--and there are a lot of really good, short YouTube tutorials etc. available.

So for free and easy (versus Sketchup: $700? but tons of customizations, models, plugins, etc.), this amateur likes it a lot. Working on my garden, tho, and it's pretty limited in terms of exterior items, so that's regrettable.

But if you just want to do a 2D layout of your room to play with furniture arrangement and then possibly look at what it would look like in 3D (and invest a bit more time in doing so), it's the perfect tool.

Requires Java.

it's easy

It's better than I figured it would be, although the interface looks like it was made in the 90's. It also needs to use an https connection. Otherwise it's a good alternative to homestyler which is a Chinese made app/site.

Architectural design

40% cpu usage on I7 processor when starting to draw a wall. I haven't seen this kind of lag since 20 yrs. :)