Most lenders will not lend more than 75 percent to 80 percent on a refinance. If the lender has an 80 percent loan-to-value (LTV) requirement and you need a $250,000 mortgage to make refinancing worthwhile, your home will have to appraise at $312,500 ($250,000 divided by .80). Often, mortgage brokers check with appraisers before they order the appraisal to see if the property is likely to appraise for a certain price. If it looks as though the appraisal could come in low, the mortgage broker might hire an appraiser who has a reputation for appraising on the high side. This will maximize the chances of the loan being approved.