Research Report

Designing Accessory Dwelling Unit Regulations

Accessory Dwelling Units (ADUs), or secondary housing units on residential lots, have the potential to increase housing supply in single-family neighborhoods without drastically altering the character of those neighborhoods. ADUs can also provide a wealth-building opportunity for cost-burdened homeowners. However, while many cities have enacted laws allowing for ADU construction, some common regulations make adding an ADU too burdensome for homeowners interested in development. This brief provides evidence and recommendations for an ADU regulation for the City of Alexandria, Virginia, that minimizes barriers to development, is sensitive to the desires of existing residents, and is designed and implemented equitably.