NYC Unveils Tools, Financing for Home Add-Ons

New program aims to make it easier for homeowners to add accessory dwelling units

Mar. 19, 2026 at 3:08am

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Mayor Zohran Kwame Mamdani announced a new set of tools and financing options to help New York City homeowners add accessory dwelling units (ADUs) to their properties. The city's new "ADU for You" website features an ADU Guidebook, pre-approved plan library, and cost estimating tools to assist homeowners. The city is also reopening applications for the Plus One ADU program, which provides up to $395,000 in financial support and technical assistance to qualified homeowners.

Why it matters

ADUs can help increase the city's housing supply while allowing homeowners to earn extra income and enable aging in place. The new tools and financing options aim to make it more accessible for a wider range of homeowners to add ADUs, which were recently legalized in many low-density neighborhoods through the City of Yes for Housing Opportunity initiative.

The details

The "ADU for You" program includes an online guidebook, a library of pre-approved ADU designs that have been reviewed by the Department of Buildings for code compliance, and site feasibility analysis and cost estimating tools. The city is also reopening the Plus One ADU program, which provides financial assistance of up to $395,000 to qualified homeowners. The program saw overwhelming interest when it first launched in 2023, receiving over 1,300 applications in just two weeks.

  • The Plus One ADU program was first launched in 2023.
  • The Plus One ADU program has been closed to new applicants since February 2024.
  • The "ADU for You" program and pre-approved plan library are launching today.

The players

Zohran Kwame Mamdani

The mayor of New York City who unveiled the new ADU tools and financing.

Leila Bozorg

The Deputy Mayor for Housing and Planning in New York City.

Ahmed Tigani

The Buildings Commissioner in New York City.

Sideya Sherman

The Director of the Department of City Planning in New York City.

Dina Levy

The Housing Preservation and Development (HPD) Commissioner in New York City.

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What they’re saying

“One of the solutions to the housing crisis can be found in our backyards, our attics, or our basements - in an Ancillary Dwelling Unit. That's why our administration is making it easier and more affordable to build an ADU through a library of pre-approved plans and new financing options.”

— Zohran Kwame Mamdani, Mayor

“In the midst of a dire housing crisis, ADUs are an important tool for homeowners to add space, bring in extra income, and stay in their communities - but creating an ADU can feel out of reach for too many New Yorkers. These new tools will help ensure that any New Yorker who wants to add an ADU is able to do.”

— Leila Bozorg, Deputy Mayor for Housing and Planning

“Ancillary dwelling units have the potential of unlock thousands of safe, quality homes for New Yorkers in low density neighborhoods across the city. However, these homes will not get built if the permitting process places too many barriers in the way. Today's announcement includes multiple tools that will help remove these barriers, including the new Pre-Approved Plan Library which gives New Yorkers a menu of potential design options that have already undergone an initial review by DOB for code-compliance leading to faster approvals.”

— Ahmed Tigani, Buildings Commissioner

What’s next

The city will continue to add more pre-approved ADU designs to the library as they are submitted by design professionals and reviewed by the Department of Buildings.

The takeaway

The new ADU tools and financing options from the Mamdani administration aim to make it more accessible for a wider range of New York City homeowners to add accessory dwelling units, helping to increase the city's housing supply while also providing homeowners with opportunities for extra income and enabling aging in place.