Looks like you finally zoned in on a property you really like. Trouble is, there are slab issues. Great advice has been given below. Slab repair companies or House leveling companies can address fixing a problem but they are not Engineers. You need the inspection, expertise and opinion of an actual structural Engineer to inspect the slab and give you a written opinion as to condition and recommended solutions. MLAB and MLAW are a couple of reputable firms but there are several others as well within the Austin area. It won't be free and maybe not even inexpensive but the cost will still be less at this point than hiring a contractor to fix the problem and you will have a certified inspection stamped by a licensed Engineer to work with. Then you can make a more educated decision.
As for slabs and warranties, this home would be well beyond the general Builder Warranty BUT usually the slab itself would still be covered under the structural warranty. These are different warranties. Most reputable builders will cover the slab for at least 10 years if not for life of the home. If there was neglegence in the design or construciton of the slab then you probably would have something to work on. BIG QUESTION: If you have not already purchased this home and you know the potential for major cost and expense exist then why buy it? Move on! There are too many nice homes and good deals out there right now to justify all the time, expense and headache of this particular home. Besides, the likely hood of finding the builder 14/15 years later is doubtful as there have been many builders who participated in the River Place development. If you do find them you still face the time /expense of litigation.
If you have further questions or need assistance please contact me at your convenience.
Good luck to you,
Stephen B. McClain, Broker/ Owner
Cornerstone New Home Solutions
512 876-3116... more