As you said, the appraisal price is 680,000 yuan, and you can borrow 70% (more than 90 square meters) or 80% (less than 90 square meters) of the 680,000 yuan. 70% is 476,000, rounded to 470,000, and the down payment is 330,000; 80% is 544,000, rounded to 540,000, and the down payment is 260,000.

If the upper limit of local provident fund is 400,000 yuan, then your down payment is 400,000 yuan. If it is difficult for you to pay a down payment of 400,000 yuan, you can increase commercial loans and make portfolio loans, as long as the seller agrees.