This is something that your board should be hiring good legal counsel, well versed and experienced in Illinois real estate law and experienced with condominiums, in particular, construction defect issues. 
 
I would HIGHLY recommend your board begin reviewing attorneys now. This is not a time to seek "opinions" on blog sites or the internet. While this is a wonderful forum, you should be asking for well known and respected attorneys in your area. 
 
This does not mean that you will definitely have court action. What this means is that you should have experienced and knoweldgable representation to act on your behalf and assist you in making informed decisions and choices. Some will want to sue to make a point. Others will want the issue resolved as quickly and reasonably as possible.  
 
I am an Association Manager for condominiums and homeowners in Michigan and while I know what Michigan requires, I would STILL be advocating the same thing to a board here. I am not an attorney and neither are you. If you are, are you a real estate attorney, conversant in real estate law? I find the best attorneys usually recommend hiring an attorney when the area in question is outside of their expertise. For example, you would not hire a criminal defense attorney for a divorce and vice-versa. 
 
The best thing your board can do is try to find legal counsel that will best fit and represent your group.

Joe Shuirmann's comment and recommendations above are excellent. Developers are notorious for making questionable repairs or otherwise dragging things out to avoid statute of limitations, while HOA Boards spin around and around wondering what to do.  
 
Interviewing and then hiring a construction defect attorney right away is the only place to start. A seasoned/effective attorney will then bring in their own team of forensic experts to evaluate the scope of your potential claim and direct you accordingly. In some states - such as California, where I'm from - statutes of limitations vary from 1 year to 10 years depending upon the item or defect. So it's *CRITICAL* that you put together your team of experts right away to make sure you don't inadvertently miss your window(s) of opportunity.

Our Association is currently in a construction litigation case against the developer/converter of apts. to condos and left us with a huge mess. 
 
Basically, you need to look at the building code violations. That way you can go after the contractor who poured the roads, and who knows what other building code violations exist. Hiring a firm to get core samples of the road and soils will clearly show you where the problem is wiht the roads. That should be done with numerous other items on your property. Usually if one thing is wrong there are more.

If you just turned over depending on where you live you should have 1 year from the date of turnover to hold the developer responsible. Just remember document everything.

 
 
My roof leaks at least 4 times the manager patch up a bit and then case close or blames on plumbing so I have to take the tab on the other hand floors and humidity has to be adress. the condo is a flmily own P.s advise