You can--and should--speak with an attorney who can evaluate your situation and confirm the following (most attorneys will talk to your for free about something this simple,just to see if you might have a case), but you probably doo not have any recourse at this time. There is something called the statute of limitations, or the time you have to bring a lawsuit. The SOL is, I believe, in GA, usually 2 years  or 6 years for a case like this, depending on the legal theory you are bringing it under. After 12 years, it's highly unlike that you would still be able to sue the builder, unless something occured which "tolled," or held in abeyance, the statute. That's what you need to discuss with a GA attorney, to see if there might be  circumstances that would toll the statute.