In todays economy it is extremely important to make sure that your credit report is at its most optimal level. Remeber any new purchases, leases, finances, or new credit cards can have a negative impact on your credit score. Even after you have applied for a loan it is important to think before increasing your debt. Your lender may reject your loan if your credit score drops in the interim.
Many purchasers feel that since the appraisal is relatively expensive they would like to delay ordering the appraisal until they are reassured that the lender will finance their purchase. That is a mistake. Most comitments are subject to appraisals but your contract to purchaser may not be subject to the appraisal and as such if the appraised value is less than expected the lender may not be in the possition to provide you with the financing you need. It is a good idea to order the appraisal before the commitment is issued.