Legal Question in Construction Law in California

Well, first of all, you probably can't get all your money back; but chances are good that you can get a judgment for the shortfall in your contractor's performance, i.e., the cost to have someone else finish up, or the value of the missing square footage. Therefore, my recommendation would be to consider a suit in small claims. A possible problem would be whether the contractor is bonded and/or solvent; sometimes failure to complete a job is a sign that the contractor is going belly up. At least in small claims it is easy, quick and cheap to find out if you can (a) win, and (b) collect. I suggest getting one of the several paperback books on how to prepare, present and win your case in California small claims, e.g. the book published by Nolo Press, but there are others. Be sure it is California oriented.

Your contractor has committed several violations of the Contractors State License law and related regulations. I'm guessing he may not be licensed either. If he does not have a valid license or at ANY time during the course of the work did not have a license, you are entitled to sue for ALL your money back. If he IS licensed, you can make a claim against his contractor's license bond for the difference between the value of the work he did and what it takes to complete the contract. If the bond isn't enough, you can sue in small claims for the difference if it is under $10K, or Superior Court for over $10k. The best place to start, is filing a complaint with the Contractors State License Board. Info at: http://www.cslb.ca.gov/Resources/GuidesAndPublications/ConstructionComplaintGuide.pdf

You can also track down his bonding company and file a claim against his bond on the cslb.ca.gov website.