Which of the following is NOT considered an improper expense according to an appraiser?

Operating expenses are typically necessary costs incurred for maintaining and operating a property, and they are considered proper expenses by appraisers. This includes expenses such as property management, repairs, utilities, and insurance, which are essential for the property's upkeep and functionality. Proper accounting for these expenses is important for accurately assessing a property's value and cash flow.

In contrast, depreciation reflects a reduction in the value of the property over time and is an accounting measure rather than an actual cash expense. Debt service pertains to the interest and principal payments on borrowed funds used to finance property acquisition or operation, which are also seen as more specific to the financing activities of the owner rather than the operational aspect of property.

Owner's personal business expenses are not related to the property being appraised and do not contribute to its valuation in a consistent manner, making them improper expenses for appraisal purposes. Thus, operating expenses stand out as necessary and appropriate costs that ensure the property is well-maintained and efficiently run, thereby supporting the appraiser's evaluation of its value.