Freestanding facility — measured from the external wall of the facility structure closest in proximity to the school, child day care center, or church to the closest point of the property line of the school, child day care center, or church. If the school, child day care center, or church is part of a larger structure, such as an office building or strip mall, the distance shall be measured to the entrance or exit of the school, child day care center, or church closest in proximity to the facility.