“We have a 21st-century economy sittin’ on a 20th-century foundation. And unless we modernize it, we ain’t gonna get moving,” Chicago Mayor Rahm Emanuel told area carpenters at a union apprentice and training shop on Thursday.

With that – and with assistance from former President Bill Clinton -- Emanuel announced the formation of a Chicago Infrastructure Trust (CIT) that will rely on private investment and bank loans to fund hundreds of millions of dollars in energy and transportation projects, beginning with $200-million plan to perform energy retrofits in city buildings. As Emanuel tells it, the retrofits would save the city $20 million per year, thereby providing the funds required to repay investors.

The mayor also envisions a rapid-bus system – which any Chicagoan can tell you we desperately need – that would charge highers fare for faster rides, creating another revenue stream to repay investors.

Similarly, distance-based fares would fund the extension of the city's Red Line rail to points further south of the Loop.

All great stuff. The devil, of course, is in the details, which remain a little fuzzy. While several large financial firms, including Citibank and J.P. Morgan Asset Management, have responded with letters indicating “support,” “high interest” or “preliminary non-binding interest” in investing in CIT programs, it's too soon to tell if or when support will translate into new projects.

And Chicago area builders need them – badly. Recent data from the Arlington, Va.-based Associated General Contractors of America indicate that recession-weary Chicago and isn't bouncing back as strongly and quickly as area builders had hoped, given the signs of improvement they are seeing in the nation's economy.

Emanuel knows it. His announcement arrived a day after his economic team unveiled plans to create jobs in Chicago. “Our needs are bigger than what Washington or Springfield can do anymore,” Emanuel said. “Their money is declining. Our needs are growing. I can either look at that challenge and stare at it and hope it gets better or do something about it.”