Sweet Home 3D is able to export the 3D view of existing designs (*.sh3D) to Wavefront OBJ format. This means it will generate an *.obj file which will be accompanied by an *.mtl file that contains material data.
Convert Sweet Home 3D design to 3D object graphics.
We found one software available in the database for this conversion.
Microsoft Windows software - convert sh3d to obj on Windows
A free interior design program
Convert from sh3d file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.