Posted: Tue Dec 12, 2017 6:09pm
You really should have learned more before you went ahead with the purchase. Did you enter into a purchase contract, specifying when and what you'd pay? If not, why not; if so, what does the contract commit you to? Did you get an insurance policy to cover e.g. repayment of stage payments if the build didn't complete for whatever reason?
Unless you've signed a contract saying otherwise, which would have been extremely foolish, you should only make the final payment in front of the notary, and make sure you get a habitation certificate before doing so.