On Arch Sweet Home 3D does not seem to work when installing from AUR so it is required to use the official installer.
Download the official installer from here http://www.sweethome3d.com/download.jsp Extract and move the extracted folder to your desired location for me it is [c]/opt/SweetHome3D[/c] To create a start menu Launcher follow these steps
sudo nano ~/.local/share/applications/sweethome3d.desktop
Paste the following texts.
[Desktop Entry]
Version=1.0
Name=Sweet Home 3D 5.7
GenericName=Interior 2D design application with 3D preview
GenericName[de]=Innenraumplaner
Comment=Interior design Java application for quickly choosing and placing furniture on a house 2D plan drawn by the end-user with a 3D preview
Exec=/opt/SweetHome3D/SweetHome3D-Java3D-1_5_2
Icon=/opt/SweetHome3D/SweetHome3DIcon.png
StartupNotify=true
StartupWMClass=com-eteks-sweethome3d-SweetHome3D
Terminal=false
Type=Application
Categories=Graphics;2DGraphics;3DGraphics;
Keywords=interior;design;2D;3D;home;house;furniture;java;
Now SweetHome3D should run just fine.