UPDATE: In January 2024 City Plan Department has proposed Phase 2 of the ADU Ordinance. This will be heard at the Board of Alders Legislation Committee on April 2 at 6:00 pm, If approved, the currently proposed text amendment will implement Phase 2 by removing the owner occupancy requirement for ADUs, as well as Phase 3 by expanding the ordinance to allow detached and attached ADUs outside of the building envelope of existing structures.  We are further proposing to eliminate the minimum lot size for ADUs, and align ADU setbacks with those of “accessory structures.”  We are proposing no change to the zones where ADUs are permitted: RM-1,RM-2,RS-1 and RS-2 zones.  Read the proposed Ordinance here.

City Plan has also prepared a Memo on Understanding the Impacts of ADUs and a folder of readings to help residents better understand the impact of the Phase 2 ADU Ordinance.  

Not unlike most cities around the country, New Haven is in the midst of an urgent and unprecedented housing crisis.  Over the last decade, while the economy and jobs have grown, demand for housing has increased but the number of housing units created is not keeping up with demand.  Elm City Communities Breaking Ground Report’s analysis of the Bureau of Labors Statistics Job Growth Data found that from 2010-2020 New Haven added 34,000 jobs but only 11,000 homes. At the same time, this shortage of supply is continuing to cost burden residents, with over half of New Haven residents spending over 30% of their income on housing (Elm City Communities, 2023).

ADUs are an appealing housing creation strategy for historic cities like New Haven because they allow minor increases in density that are largely invisible within neighborhoods and without the construction of large-scale housing developments.  ADUs are typically located in backyards, existing garages, and converted interior spaces and make use of existing, often underutilized, buildings.  In many ways, use of these existing buildings helps to retain the character of historic neighborhoods and is a sustainable alternative to demolishing structures and building new large-scale housing. ADUs have advantages for both the property owner and potential tenants as well. Proponents argue that they tend to be more affordable than single-family housing, because the units are small and typically have fewer amenities (e.g., lower ceiling heights, less space per person.  This is discussed in depth below).  For many existing homeowners, ADUs provide opportunities for multigenerational households to enable family members to age in place and accessible housing for seniors and persons with disabilities. This is one reason why the American Association for Retired Persons has been an advocate for ADU building nationally.  

The City of New Haven Accessible Dwelling Units (ADU) Ordinance aims to create new housing units while respecting the look and scale of neighborhood patterns of development, increase affordable housing choices especially for very low-income residents, support more efficient use of existing housing stock and infrastructure and offer environmentally friendly housing choices with less average space per person and smaller.  The Ordinance may be found here on Legistar.

For more details on how to get started with an ADU, visit the Accessory Dwelling Unit Toolkit.

Thank you to the following team for their contributions to the ADU Toolit:

Yi-Ming Wu and Cindy Duan, Yale School of Architecture, lead designers; Ming Thompson, Atelier Cho Thompson, lead advisor;  Caitlin Yu, Joey Reich, Marie Corriveau, advisors and City Plan Staff Will Long, Nate Hougrand, and Laura Brown.