To Dorin
Thank you for the advise,
Downloaded plugin as your suggested, on Readme.txt there is explanation to install under Linux and other Unix, it's the subfolder .eteks/sweethome3d/plugins of your user folder, I cant find the subfolder eteks in plugins.
My SH is .tgz file don’t know if there is a difference, please advise.

To Okh
Thank you for your advise, it works.