Accessory Dwelling Units: Exploring Options for Affordable Housing in New York City

The New York City Department of Housing Preservation and Development (HPD) is the largest municipal housing preservation and development agency in the nation. HPD promotes quality housing and thriving neighborhoods through preservation and development programs for affordable housing. HPD engaged a Capstone team to conduct an in-depth review of New York City’s interrelated regulatory, policy, and financial issues associated with accessory dwelling units (ADUs). ADUs are residential units that are often found in basements, attics, or garages in one- to four-family homes. ADUs can be a source of affordable housing and provide homeowners with rental income. The Capstone team was charged with reviewing best practices in ADU development nationally and internationally; identifying building typologies that are suitable for ADU development in New York City; investigating the potential for incentivizing New York City homeowners to develop and legalize ADUs in their properties; calculating the potential cost of ADU development; and identifying policy and regulatory implications of ADUs.