There's no easy answer, because what a buyer might be willing to pay depends on many factors — everything from the choice of project to the materials you use to the value of other homes in your neighborhood.
It's the fundamental question facing anyone who has ever embarked on a home renovation: How likely am I to get the money back when I sell my house?
This will force the Sydney Symphony Orchestra, who rehearse in the building weekly, to relocate while renovations are underway.
Sydney Symphony Orchestra chief conductor David Roberston did not mention an inconvenience created by the concert hall shutdown and instead welcomed the improvements."The concert hall at the moment is a little bit like Hubble telescope was when it was first put up, breathtaking images and very inspiring, but nothing like the fix that happened when they actually got the mirror focused," he said.
Mr Robertson said the renovations would improve the acoustic clarity of the concert hall.
The remainder of funds will go to a function centre, a creative learning space, and upgrades to the building's entrance and foyer.