Collada export and re-import to a new model

I have two models, both seem to be performing well, no glitches. I want to merge the models (they are adjacent parts of a house extension) and have exported both models in Collada format. On importing them both into a new model, one works fine, the other is one big component which won’t explode - much of it disappears.

Is there some step missing, I wonder? I don’t believe Collada export and import itself can be at fault - do I need to flatten layers first, or adjust the components in some way? I can’t find anything in the videos or help texts anywhere…

Or perhaps I can take a simpler route I have not spotted? Any thoughts welcome…

Thanks,

Chris

except it isn’t needed to make a merged skp files and NO export to a different format is lossless…

you could use 'File >> ‘Import’ on the both into a new skp…

john

Thanks John, you just saved me from ditching and rebuilding from scratch.
Worked first time, thanks.

Chris