What causes an unfavorable fixed overhead budget variance?

An unfavorable fixed overhead budget variance results when the actual amount spent on fixed manufacturing overhead costs exceeds the budgeted amount. The fixed overhead budget variance is also known as the fixed overhead spending variance.

Fixed overhead costs are the indirect manufacturing costs that are not expected to change when the volume of activity changes. Some examples of fixed manufacturing overhead include the depreciation, property tax and insurance of the factory buildings and equipment, and the salaries of the manufacturing supervisors and managers.

Since the fixed manufacturing overhead costs should remain the same within reasonable ranges of activity, the amount of the fixed overhead budget variance should be relatively small.