Hi Gary, I've dealt with lots of these problems and unfortunately the remedy is not an easy one on your case. When the windows were installed, a piece of metal should have been placed over the windows to act as a "head flashing" to direct water away that finds its way behind the siding. I would bet this detail was omitted during construction, as it is quite often these days with lesser-skilled labor and tight budgets. I am assuming you probably have synthetic stucco, or EIFS (External Insulation and Finishing System). I would be even more concerned with the framing within the wall on a leaky EIFS job. The stucco provides a waterproof barrier if installed correctly, but if water penetrates the system, it can not escape easily and is the cause of millions of dollars worth of structural repairs each year in this country. I would contact an ASHI certified home inspector and ask to have an EIFS inspection performed. They will test the framing within the wall with a water meter to determine if framing is damp and will also be able to properly diagnose the absence of head flashing. Armed with his results, you and your neighbors, should attempt to have the builder correct the problem, regardless of the one-year limit on new home defects allowed in most new home contracts. There are numerous class-action lawsuits against EIFS manufacturers for providing faulty details that have had subsequent failures, and your inspector will be able to advise you on whether you would be eligible to collect. I suspect the builder will be liable and you may need to sue to get recourse, as the areas above the windows need to be stripped of their finish, down to the sheathing, and the flashing installed and the EIFS correctly terminated at the windows. Manufacturers are very specific about the details around termiations like windows, doors, light fixtures, and outlets. Good Luck.