Buildings are just one focus of surveys. Historic and cultural resources can be individual buildings and structures, or groups of properties that form districts or cultural landscapes, as well as objects, archeological resources, works of art, or flora such as trees.

Generally, surveys investigate buildings that were constructed more than 50 years ago. However, certain buildings from the more recent past can also be included in a survey if they feature outstanding architecture, craftsmanship, or materials, or if they are closely associated with a recent significant event.

There are two types of historic resource surveys: Reconnaissance and Intensive. Reconnaissance surveys, aka windshield survey, document the physical qualities of the property, but make no formal evaluation as to a building’s significance, integrity, or eligibility to local, state, or national registers. An Intensive survey requires more intensive research and documentation of a property, and most significantly, results in the evaluation of a property’s eligibility for local, California, or National listing. Evaluation can apply either to individual properties or to properties within the context of a historic district. In general, surveys usually begin at the Reconnaissance level. After additional research and identification of property types, a smaller number of properties are selected for time-and-research-heavy Intensive surveys.