Sweet Home 3D was translated into Finnish (Suomi) and Serbian (Српски) recently. As for recent translations, these languages are made available in Sweet Home 3D through SH3L files you can download from the new Translations page added to the web site.
In the last version 3.4, I also added a new button in the Preferences pane to simplify the installation of a new language SH3L file, in case a simple double click on a SH3L file doesn't succeed to install it (this is miserably the case for most Linux users).
If you need to upgrade a more recent version of a SH3L file (like the Traditional Chinese language file updated for version 3.4), don't bother about removing any file: install the new SH3L file the same way and just restart Sweet Home 3D, which will take care of choosing the most recent version.
Many thanks for their great contribution to Jukka Hyytiälä, Иван Старчевић and Снежана Лукић and to all the other contributors who helped to translate Sweet Home 3D in other languages!