There are three situations where the lender may order a second appraisal. If it has been three to six months since the original evaluation, the lender will order a second one to ensure no changes have occurred. This often happens when the home being purchased is a foreclosure home. The second reason is based on the type of loan the buyer is getting. Some loans require a second appraisal. Third, it could be that the seller is unhappy with the original evaluation and has requested a new one.