I want to download Sion neighborhood. The creator invited to complete it with lots and to share filled Sion on MTS. This provoked me to think, what if, hipotetically, I filled it with lots which are not mine but downloaded from MTS, just like Sion? Obviously all credits of lots' creators have to be attached. Will I need permission for every single lot to upload them in packed neighborhood? Or is it possible to say already at this point that project like this has to fail eventually?

Sorry if it was answered before, but I didn't find any clues besides this thread where Mootilda was talking about installing new lots via Sim2Pack in order to create shareable occupied neighborhood.

I may be called uncreative, but what I like the most is putting things together to achieve best combination and looking at them from different points of view, searching for perfect arrangement. I think it is similar to decorate interiors with custom furniture but the interior is neighborhood and furniture is lots.

You will need permission from some creators and not others, it really depends on their terms of use policy.

If uploading to MTS, you would most definitely need explicit permission from each lot creator. If you are simply taking other peoples lots, then you would need to put a lot of effort into creating a new neighborhood map and decorate it to make it unique. Because, tbh, I'm not sure if using an EA .sc4 and putting others lots into it would be unique enough to be accepted here as anyone could really do that quite easily.