The definitions shall be as follows:
CERTIFICATE OF APPROPRIATENESS: The certificate issued by the commission approving alteration, rehabilitation, construction, reconstruction or demolition of a historic structure, historic site or any improvement in a historic district.
COMMISSION: The historic preservation commission created under this chapter.
EXTERIOR ALTERATION: Any modification of exterior dimensions of a structure including the attachment of appurtenances such as stairs, fire escapes, chimneys, carports and other similar construction or the modification of materials including, but not limited to, roofing, siding, masonry, wood trim, windows or signs. Normal maintenance of existing exterior features or materials including cleaning, painting or replacement shall not be considered exterior alterations.
HISTORIC DISTRICT: An area designated by the common council on recommendation of the commission, that contains two (2) or more historic improvements or sites, as well as those abutting improvements parcels which the commission determines should fall under the provisions of this chapter to assure that their appearance and development is harmonious with such historic structures or historic sites.
HISTORIC SITE: Any parcel of land of historic significance due to a substantial value in tracing the history or prehistory of man, or upon which a historic event has occurred, and which has been designated as a historic site under this chapter, or an improvement parcel, or part thereof, on which is situated a historic structure and any abutting improvement parcel, or part thereof, used as and constituting part of the premises on which the historic structure is situated.
HISTORIC STRUCTURE: Any improvement which has a special character or special historic interest or value as part of the development, heritage or cultural characteristics of the city, state or nation and which has been designated as a historic structure pursuant to the provisions of this chapter.
IMPROVEMENT: Any building, structure, place, work of art or other object constituting a physical betterment of real property, or any part of such betterment, including streets, alleys, sidewalks, curbs, lighting fixtures, signs and the like.
IMPROVEMENT PARCEL: The unit of property which includes a physical betterment constituting an improvement and the land embracing the site thereof, and is treated as a single entity for the purpose of levying real estate taxes. Provided, however, that term "improvement parcel" shall also include any unimproved area of land which is treated as a single entity for such tax purposes. (1975 Code Ch. 21 § XXXII)