Sorry to hear about your extra expenses, but don’t worry about canceling your preapproval!
Because a preapproval isn’t legally binding, you can simply walk away. Out of courtesy, you may just want to call the lender to tell them what’s happening. Not only will this provide a better rapport for future loans, but you can also avoid an onslaught of follow-up phone calls from the lender.
The circumstances may be different if you’ve already signed for the loan, however, as you generally cannot cancel a loan that easily.