NYC Reopens Homeowner Program To Streamline And Support Additional Housing Units

New York City is backing homeowners by relaunching a program designed to help them add additional units to their existing properties.

Securing housing in New York City is no easy task, but the city has reopened a program to help homeowners build additional units on their existing properties.

On March 18, New York City’s Housing Preservation and Development (HPD) and Department of Buildings (DOB) announced the relaunch of the Plus One ADU program, along with a new “ADU for You” toolkit, offering subsidized financing and resources to streamline and simplify the permitting process, Realtor.com reports. Reopening for the first time since its 2024 launch, the Plus One ADU program offers eligible homeowners up to $395,000 in financing through NYC HPD and New York State Homes and Community Renewal to build an accessory dwelling unit, commonly known as an in-law suite, backyard cottage, garage conversion, or basement apartment.

Mayor Zohran Mamdani framed the initiative as a way to expand housing while preserving the character of local neighborhoods.

“By making it easier for New Yorkers to turn their homes into an extra place for a loved one or a little more income, we’re allowing our city to grow while keeping the character of the neighborhoods we love,” Mamdani said.

The program targets low-density neighborhoods across all five boroughs, though the city has not outlined detailed income or eligibility criteria beyond saying it’s open to “qualified homeowners.” The companion “ADU for You” site offers a guidebook and planning resources, including a new Pre-Approved Plan Library with designs that have already undergone initial Department of Buildings code review.

The city says a wide range of spaces qualify for conversion, including backyard cottages, garages, attics, and basements. For homeowners facing rising mortgage costs, renting out a basement unit could provide meaningful income, while building a backyard cottage offers families a practical option for keeping aging relatives close.

The program aims to support both homeowners and renters as the city faces its worst housing shortage in more than 60 years, with a vacancy rate of just 1.4% in 2023. The crisis stems from supply failing to keep up with demand, with more than 500,000 new units needed to stabilize the market. It has hit low-income residents hardest, while high construction costs, regulations, and zoning limits continue to slow new development.

As for the reopened ADU program, the city says starting with a pre-approved design can speed up permits, as it’s a major advantage for homeowners navigating the DOB process. Buildings Commissioner Ahmed Tigani emphasized that projects won’t move forward if permitting is too burdensome, while Deputy Mayor for Housing and Planning Leila Bozorg said the new tools are meant to make ADUs more accessible to New Yorkers.

With strong demand during the program’s last rollout, homeowners interested in adding a unit are encouraged to take action.