As long as they are in your project you can still get them into your library, export them, 1 at a time, import it, during the import process make sure the box is checked to add to library, name the object, choose a folder to add it to, existing or create 1, i save mine to a folder called "mine ...

Great help guys, and thank you for the input, will try these ideas and give feedback, cheers !

Thank you very much, I will try that and YES, I do remember that many of them, most of them actually I just didn't bother with naming or checking anything on that last screen before the actual "adding" of the object finished, great input, thnx !

So, I know how to import furniture and use it, both Collada files and KMZ files are working fine for me, I import and it the piece of furniture shows up on my floor plan and I use it, perfect, BUT I just recently noticed that all the furniture I have manually imported piece by piece is nowhere to be ...