Absolutely right. The two have to act in conjunction – you need your by-laws to say you can’t make changes to common property without permission but if you do, you and subsequent owners are responsible, not just for their repair and maintenance, but for any damage the changes may cause to the rest of the building.
FYI: A friend recently sold an investment property and as part of the disclosures to the new owner, he had to state that he hadn’t made any changes to common property while he was in possession of the apartment.