Sweet Home 3D 5.6
Sweet Home 3D 5.6 was released on October 25, 2017 with bug fixes and minor improvements described in version history.
I checked how Sweet Home 3D 5.6 works under macOS 10.13 (High Sierra) where you'll have to download Java 6 to run the installer version, or install Oracle Java version to launch the Java Web Start version (prefer latest Java 8u152 which fixed many bugs under macOS).
[Update on November 2nd, 2017] Under High Sierra 10.13, the installer version had an issue with its menu bar which appeared at the top of Sweet Home 3D windows instead of the top the screen when system primary language wasn't English, but Apple fixed this bug in High Sierra 10.13.1.
I also checked that Sweet Home 3D works correctly under Windows 10 Fall Creators Update where I didn't notice any issue. Nevertheless, if Sweet Home 3D reports at launch an error about the graphics driver (particularly if the graphics card is integrated to an old Intel processor), try to run again the installer from the command line with the two parameters /j3d.version=1.5.2 /os.arch=x86
. This will force to install Sweet Home 3D 32 bit with Java 3D 1.5.2, a solution that works for some users.