Preservation of an historic building. A building or structure classified as historic, or any part or appurtenance, including but not limited to stone walls, fences, light fixtures, steps, paving, and signs, shall only be moved, reconstructed, altered, or maintained in a manner which will preserve the historic and architectural character of the building, structure or appurtenance. Provisions for handicapped access as required by state and federal law shall be provided in a manner which preserves the historic and architectural character of the building or structure.