The appraisal is one of the few points in a mortgage where the consumer holds specific, dated, enforceable rights, and they are easy to let lapse unused.
The rights, at 12 CFR 1002.14. The creditor must mail or deliver written notice of the right to receive a copy of all written appraisals no later than the third business day after receiving the application. It must then provide a copy of each appraisal or other written valuation "promptly upon completion, or three business days prior to consummation of the transaction ... whichever is earlier." It may not charge for the copy, though it may charge a reasonable fee for the appraisal itself. And the rule that gets overlooked is subsection (a)(4): those requirements apply "whether credit is extended or denied or if the application is incomplete or withdrawn." Someone turned down for a mortgage is still entitled to see the valuation that helped turn them down.
The appraiser is meant to be insulated from the outcome, and the regulation says so in unusual detail. Under 12 CFR 1026.42(c)(1) nobody with an interest in the transaction may cause a value to be based on anything other than the appraiser's independent judgment, and the examples the rule gives are the practices it was written to stop: seeking a minimum or maximum value, withholding payment because a value came in low, implying that future work depends on the number, dropping an appraiser for reporting a value below a threshold, and conditioning the fee on the loan closing. This is why a borrower who thinks a value is wrong generally has to challenge the reasoning, comparable sales and factual errors rather than ask for a different answer.
On some purchases the lender must obtain two appraisals and may charge for only one. For a higher-priced mortgage loan financing a principal residence, 12 CFR 1026.35(c)(4) requires two written appraisals where the seller acquired the property 90 or fewer days earlier and the new price exceeds the seller's acquisition price by more than 10 percent, or acquired it 91 to 180 days earlier and the price exceeds theirs by more than 20 percent. Different appraisers must perform them, one must analyze the price difference, market changes and any improvements made, and the creditor "may charge the consumer for only one of the appraisals." Both appraisals require a physical visit of the interior. The rule exists for quick resales at a large markup, and it is the closest thing in federal mortgage law to a second opinion the buyer does not pay for.
What the appraisal does not do is the part worth being blunt about. It does not certify that the roof is sound, that the systems work, or that the house is worth what it costs to live in. FHA's form states that FHA "does not guarantee the value or condition" of the home, and that if problems turn up after closing, FHA "cannot give or lend you money for repairs" and "cannot buy the home back from you."