Base Unit Layers is a hosted feature service containing three related base geography layers: Addresses, Streets, and Buildings. These layers provide foundational location features and identifiers used to connect addresses, buildings, parcels, units, street segments, and related location records. Along with Parcels data, these layers form the basis of the Base Unit Tools map and geocoding application. Datasets are updated regularly as necessary. Please let us know of any data issues you find with the Base Unit Tools “report issue” feature.
Data included
Addresses — point features representing address locations. Address locations represent the center point of related physical objects. When an address is related to a building or a unit in a building, its point location is the center point of the related building. When an address is related to a parcel, its location is the center point of the related parcel. The Addresses dataset was created and is updated by the Department of Public Works Maps & Records Division and the Department of Innovation and Technology (DoIT).
Streets — line features representing street segments, including street name components, address ranges, and classification attributes.
Buildings — polygon features representing building footprints and related identifiers, including building ID, parcel ID, SEMCOG ID, status, alternate names, and condo plan number. The Buildings dataset was created and is updated by the Department of Innovation and Technology (DoIT).
These layers are intended to support address reference, base map production, spatial joins, geocoding support, parcel/building/street relationship workflows, and other applications that require consistent base unit identifiers.
To look up individual locations or for geocoding, we recommend using the Base Unit Tools map and geocoding application, which includes Addresses, Buildings, Streets, Parcels, and Street View data. The Street View data in Base Unit Tools can also be found from Detroit Street View Panoramic Imagery on the ODP.
How this data can be used
Map and query address, street, and building base unit features.
Relate addresses to buildings, units, and street records using published identifier fields.
Support address validation, base mapping, spatial lookup, and internal data integration workflows.
Provide reference geometry for applications that need address points, street centerlines, or building footprints.
Do not use this data for
Determining legal property boundaries; parcel IDs are included, but parcel geometry is not part of this service.
Engineering, survey, or construction-grade measurement without confirming data accuracy and projection details.