The Old Towne Historic District was placed on the National Register of Historic Places in 1997 and includes more than 1,300 homes and other buildings. It is approximately one square mile in size, making it the largest National Register District in California. The District provides a feeling for life in Orange from 1888 to 1940, showcasing over 50 different architectural styles. The complete stock of buildings which are a part of the Old Towne community is complemented by the churches, schools, old Santa Fe Depot, Post Office, packing houses, industrial buildings, clubhouses, and parks which still remain in active use since their establishment in the early part of the century.
To build upon the documentation of property in the Old Towne Orange National Register District nomination, the City surveyed all pre-1940 buildings in 1982 (updated in 1992) and established expanded Local Historic District boundaries that include properties on the periphery of the National Register District in recognition of the fact that while these areas may not meet the National Park Service criteria for National Register designation, they bear a relationship to the National Register District and remain special areas of historic importance in Orange that warrant preservation and conservation.
A number of technical guides have been developed by The National Park Service to educate the public about proper approaches to preserving, rehabilitating and restoring historic buildings. These Preservation Briefs cover a wide range of topics including:
Exterior building additions
Cleaning methods for building exteriors
Siding treatments for historic wood frame buildings
Wooden window maintenance
Exterior paint problems
Historic storefront rehabilitation
Masonry maintenance practices
Use of substitute materials
A number of Preservation Briefs are available on-line, while others can be ordered directly from the National Park Service.