While determining the net operating income of an investment property, which expense is typically not considered?

The net operating income (NOI) is a critical metric used to evaluate the profitability of an investment property, reflecting the income generated by the property minus the operating expenses directly associated with the property’s operation. When calculating NOI, certain costs are excluded because they don't directly relate to the operation of the property itself.

In this context, interest expense is typically not included in the NOI calculation. This is because NOI focuses on the operational performance of the property before financial costs such as mortgage interest are considered. By excluding interest expense, NOI provides a clearer picture of how well the property generates income from operations alone, independent of the financing structure.

On the other hand, property taxes, maintenance costs, and insurance costs are all part of the operational expenses. These costs are necessary for the property's operation and upkeep, and they must be accounted for when determining the property’s profitability through NOI. By excluding interest expense, it allows investors to make comparisons across different properties without the variations introduced by different financing arrangements.