Tutorial: How to share apartments in the gallery for the upcoming City Life

@Silvakristiina If you have what appears to be a single room that's somehow broken into two pieces, that means one of the pieces is missing the ceiling so it considers it separate. You have to click one of them, go up a floor and click the yellow border at the top of the walls ad hit build ceiling. If that one only says remove ceiling, it has one already so try the other one.

And yes, You will have to rebuild one tile of each wall after placing to form them into proper rooms.