The $2.6 billion figure is the total of the estimated $50,000 needed to repair each housing unit, TCH CEO Greg Spearn told CBC News.
"That's a bargain, we think, compared with having to replace the buildings if we don't repair them," he said.
The replacement cost is $250,000 to $300,000 per unit, said Spearn, a former real estate executive who took over at TCH in April, who explained what will happen if the funding doesn't materialize.
"We'll have to slow down the project significantly and within five years about 4,000 units will potentially become unlivable. Our buildings are aging out. They're more than 50 years old. It's time to make a decision to let it go or fix it and extend their life by 40 or 50 years."
Mayor John Tory has called the need for TCH repairs a "crisis" and is tapping the provincial and federal governments to chip in on the bill.
"This problem will not be solved with the resources of city taxpayers alone," the mayor said shortly after being elected. "The dialogue with the other governments … has been basically non-existent. And I will be moving to change that."
Saying that the city has contributed its portion to the daunting repair budget, officials are taking the remaining $1.5 billion to the province and the feds.
Coun. Ana Bailao has been tapped to oversee the portfolio this term.
More seniors living on the streets
Tory has called the repairs a priority and says he'll push the other levels of government to provide matching funds.
"The mayor has told me he's committed to housing and repairing our buildings," Spearn said. "I feel very good about the fact that he has some good bridges built between the provincial and federal governments and that will help us as we seek the additional support."
Tory has also said the homeless population is becoming more diverse, with an increase of seniors among those living on the streets. He said aboriginals represent one per cent of the city's population, but nearly 20 per cent of its homeless population. He said the push to eradicate child poverty has stalled, which he called "unacceptable."
The city has roughly 140,000 people living in 60,000 TCH units, according to Spearn.