Hi there,

I bought an house and gaodim SNP and loan agreement recently and
House agent said after my bank paid the owner bank's for remaining balance then I can get key

The above statements seemed to be contradicting with each other. I believe your meaning of 'gaodim SNP and LA' means you had signed the documents and not the whole process of conveying the owner's interests to you. SNP is a contract where it will stipulate the payment terms and not the final step. You will only become the legal owner when the title/interest is registered under your name. Nobody will let you to be registered as the owner unless the owner (or owner's bank) receives the money. Nothing more or nothing less.

Signing the documents do not mean you will get the property immediately. Part of the purchase price (including your loan) will be used to settle the owner's outstanding loan. If got extra, only give to owner.

Thereafter, the owner's bank will return the title/original security documents your lawyer for registration.

when I can get the key? The process takes about 3 months from the date of the SNP.

I start reno the house etc, who pay the bill ? Better consult your lawyer.