504 loan program requirementssba 504 loan requirements504 loan qualificationssba 504 loan occupancy requirementssba 504 loan appraisal requirementssba 504 loan program requirementssba 504 requirementssba 504 loan applicationsba 504 loan qualificationssba 504 loan guidelinessba 504 appraisal requirementssba 504 eligibility requirements