At this time, once installed, Sweet Home 3D can work on a computer unconnected to Internet, but requires updated OpenGL/DirectX drivers for the video card.

When the user install it with Java Web Start (see http://www.sweethome3d.eu/download.html for more information), the user must accept a certificate to run Sweet Home 3D, because it requires to access to disk and to DLLs (for 3D).
No authentication is required.