The First Division champions' ground-sharing proposal with Aberdeen received a 10-2 majority backing.
Partick Thistle, who stand to be relegated by the decision, failed in a legal bid to halt the meeting and now appear resigned to the situation.
The SPL also voted to approve stadium requirements of 6,000 seats instead of 10,000 from the season after next.
Partick appeared to have been saved from relegation when the 12 clubs initially voted 7-5 in favour of Caley Thistle's proposal to share Pittodrie - one short of the eight required for change.
But Hearts and Hibernian forced a second vote on the grounds that the clubs had received unclear advice in making their original decision.