How often must the assessor certify that a property still qualifies for historic exemption?

The correct answer is that the assessor must certify that a property still qualifies for a historic exemption annually. This requirement is in place to ensure that properties receiving tax exemptions for their historic status continue to meet the criteria set forth for such exemptions. Annual certification allows for a regular review of the property's condition, usage, and adherence to preservation standards, which can change over time. This ongoing evaluation helps maintain the integrity of the historic preservation efforts and ensures that benefits are being applied appropriately and fairly.

In context, the other timeframes mentioned, such as every three years or every five years, do not fulfill the need for consistent oversight that annual certification provides. Likewise, certifying at the time of sale would not ensure continuous compliance with the historic preservation criteria and could lead to lapses in status for properties that are legitimately deserving of the exemption throughout the year. Thus, the annual certification requirement underscores the importance of maintaining standards for properties benefiting from historic preservation exemptions.