Under all state's subdivision laws a tentative map and a final map is required in the application process approved by a given municipality's permit and resource department. The tentative and final map for a subdivision only pertain to the configuration of streets, utilities to be installed and the lots.The actual homes to be built are through another process after final map approval is made where the developer then goes through a process to get approval of the homes intended to be built.Unfortunately from what I see in your question, your measure of damages would be determined at the time of your purchase as to whether you overpaid for the lot that you built. If your property decreased in value due to market conditions or the presence of low income housing, under the law it does not appear that such would be a proper measure of damages for you.