Accessory Dwelling Unit (ADU) Potential in the SCAG Region


Promoting accessory dwelling units (ADUs) construction is an increasingly viable option for addressing the region’s housing needs. To support ADU planning, SCAG has collaborated with Cal Poly Pomona’s Department of Urban and Regional Planning to identify parcels with potential for detached ADUs based on physical capacity using criteria from recently amended State law and parcel-level geospatial data from SCAG. The 6th cycle housing element requirements involve estimating ADU development potential, removing barriers to their development, and programs incentivizing ADUs including affordable rental ADUs.

This project comprehensively examines the physical ADU capacity of sites in the six-county SCAG region, focusing only on detached ADUs. ADU eligibility and physical capacity under a range of local policy scenarios have been incorporated into the Housing Element Parcel (HELPR) tool to enable users to screen sites based on this study’s criteria. Part of SCAG’s regional data platform, the HELPR tool allows users to explore and analyze over five million parcels in the SCAG region based on updated, curated versions of parcel-level land use data in light of recent housing element requirements.

Download the Accessory Dwelling Unit (ADU) Potential in the SCAG Region report.