Note: These are the Department of Public Works Basemap Parcels, not the Assessor-Recorder's Taxable Parcels. See "How to use this dataset" for more information.

A. SUMMARY Parcels are defined areas of land, demarcated by boundaries to visualize distinct and legal parcels of real property. Occasionally, parcels are divided or combined, and a new parcel can be created. This dataset connects current parcels in San Francisco to historical parcels that are associated with it.

B. HOW THE DATASET IS CREATED This dataset utilizes the parcel change log to find associated parcels through an iterative process.

C. UPDATE PROCESS This dataset will be refreshed daily, though the data may not change every day.

D. HOW TO USE THIS DATASET The City and County of San Francisco has two related but distinct parcel databases. The first is managed by the Department of Public Works, is created by surveyors, and is used in the Department of Public Works basemap. Public Works parcels are used to identify very precisely where private properties end and where public City property begins (e.g. sidewalks, roads, rights of way, etc.). The second is managed by the Assessor-Recorder's Office. Assessor parcels are defined by Revenue and Taxation code and Property Tax law. The Assessor-Recorder uses official maps defined under Revenue and Taxation code section 325 in the creation of assessor parcels and are used to identify taxable property. Each of the Assessor's parcels have an Assessor's Parcel Number (APN) which is used by other departments including but not limited to Tax Collector for tax collection, DBI for permitting, and other use cases.

Though most parcels are the same between Public Works and the Assessor’s Office, they are not a perfect match. APN's are retired and activated within the timeline parameters of tax years (July – June) based on tax roll state requirements, which means there can be a lag between the Public Works parcel changing and the associated APN being updated. Public Works’ City Basemap identifies legal parcels defined by California Code Subdivision Map Act and Assessor-Recorder’s parcels identify taxable parcel boundaries defined by Revenue and Taxation Code.

Use this dataset to identify historical parcels from the Public Works Basemap that are associated with an active Public Works basemap parcel. This dataset is not a history of the Assessor-Recorder's Parcels.

E. RELATED DATASETS Parcel Change LogParcels - Active and Retired