The 19- and 13-story high-rise project of 366 luxury apartments was planned in March 2020, but both the council and developer had argued over the requirements of Section 106.
Under the agreement, De Trafford will initially pay £ 330,000 for affordable off-site housing for the first phase of development.
It was agreed upon following a profitability assessment prepared by Eric Wright Construction and consultant Gleeds, which provided a forensic breakdown of how much money it will cost to deliver Gallery Gardens.
Construction costs for the first phase were estimated at just over £ 62 million.
The project will be located in Castlefield between Hulme Hall Road and Ellesmere Street.