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.
- Reconnaissance surveys (aka “windshield surveys”) document the physical qualities of the historic resource with a description of the resource, photographs, and documentation of the building’s age. No formal evaluation as to a building's significance, integrity, or eligibility to local, state, or national registers is completed.
- Intensive surveys require more intensive research and documentation of a property by including an assessment of the building’s historic context, significance, construction history, integrity, and eligibility for local, State, or National listing. Evaluation can apply either to individual properties or to properties within the context of a Historic District.