Throughout this chapter, the following definitions shall apply:
(a) "Downtown area" means that area of the University Avenue business district subject to Chapter 18.48 of Title 18 of the Palo Alto Municipal Code (the Zoning Code) and all zones within the geographical boundaries shown on the maps incorporated into Chapter 18.48, including planned community and public facility districts.
(b) "Historic categories" means those categories established to define and categorize the historic structures/sites on the historic inventory. Those categories are as follows:
Category 1: "Exceptional building" means any building or group of buildings of preeminent national or state importance, meritorious work of the best architects or an outstanding example of the stylistic development of architecture in the United States. An exceptional building has had either no exterior modifications or such minor ones that the overall appearance of the building is in its original character.
Category 2: "Major building" means any building or group of buildings of major regional importance, meritorious works of the best architects or an outstanding example of an architectural style or the stylistic development of architecture in the state or region. A major building may have some exterior modifications, but the original character is retained.
Category 3 or 4: "Contributing building" means any building or group of buildings which are good local examples of architectural styles and which relate to the character of a neighborhood grouping in scale, materials, proportion or other factors. A contributing building may have had extensive or permanent changes made to the original design, such as inappropriate additions, extensive removal of architectural details, or wooden facades resurfaced in asbestos or stucco.
(c) "Historic district" means a collection of buildings in a geographically definable area possessing a significant concentration or continuity of buildings unified by past events, or aesthetically by plan or physical development. A district should have integrity of design, setting, materials, workmanship and association. The collective value of a historic district taken together may be greater than the value of each individual building. All structures/sites within a historic district are categorized as significant on the historic inventory.
(d) "Historic inventory" means the current edition of the Palo Alto Historical and Architectural Resources Report and Inventory, and the master list of categories for those structures or sites.
(e) "Historic structure/site" means any structure or site within the city which has been identified as having historic or architectural significance and has been placed on the historic inventory of the city of Palo Alto, including structures and sites within categories 1, 2, 3 or 4, and all structures within historic districts.
(f) "Significant building" means any building, group of buildings or site categorized on the historic inventory as number one or number two and all structures within historic districts.
(Ord. 3721 § 1 (part), 1986)