The project was initially budgeted at $40 million and subsequently revised to $60 million.
City staff now want an additional $10 million for the project.
Council will have to approve the extra funds. It's not clear whether it will do that.
The work on the project may not be complete until 2019, almost a decade after the renovation began.
Click on the video above to see a full report from the CBC's Jamie Strashin.