Many open source software have .po files technique on translating. You can add that to some future version of SweetHome3D. It's easier to translate. Maybe there can be setting to charset. So, program displays right letters in every case.

Hmm. My Linux computer has UTF-8 charset. Scandinavic letters looks weird. I try to use latin-1 ?

Thank you. I try translating and send the result when I have done it.

I downloaded Sweet Home 3D for 64 bit Linux. And then I found a 11 and half years ago made home model from my backups. Then I loaded it to latest version 6.5. It worked fine!!

There are some untranslated phrases in Finnish translation package. Can I continue that translating?