Fees are payable either in the form of a retainer payable in advance of a scheduled appointment or by billing for actual inspection hours and travel expenses at the conclusion of inspection (or in incremental billings if inspection takes place over several days, weeks or months). Additional billings for inspection time, research and preparation time, consultation fees, etc. are billed and payable prior to presentation of the appraisal report. Fees are structured either on a per-diem or hourly basis.