Mayor Zohran Mamdani has launched new resources to help homeowners add ancillary dwelling units (ADU) to their properties, which City Hall says will help homeowners remain in their communities by bringing in extra income.
Mamdani also announced that the city is once again accepting applications for the Plus One ADU program, which provides up to $395,000 in financial support for eligible homeowners who wish to add an ADU. The program had been paused for the past two years.
ADUs, which are often referred to as granny flats, can be basement apartments, attached additions to a property, attic or garage conversions, or detached backyard units.
On Wednesday, Mamdani announced plans to launch an online resource for ADUs, including a library of pre-approved ADUs, cost-estimating tools and site feasibility analysis.
The Mamdani Administration said the online resource – called ADU for You – will help homeowners navigate financing details and cut bureaucratic red tape.
The city’s new pre-approved plan library is launching with 11 designs that have already been reviewed and approved by the Department of Buildings (DOB). Homeowners who select an option from the library will be connected with the registered professional who created the design in order to obtain site-specific approval as part of a simplified permitting process.
The DOB will also review and add additional pre-
The city’s Plus One ADU program, meanwhile, had been shuttered since February 2024 but saw significant demand when it first launched, receiving 1,300 applications inside the first two weeks. A majority of those applications came from Queens, Staten Island and the Bronx, with homeowners seeking to obtain a loan to add a unit to their property.
Thanks to zoning changes implemented as part of former Mayor Eric Adams’ City of Yes, homeowners of one and two-family houses can add one unit measuring up to 800 square feet to their property.
Mamdani said ADUs are “one of the solutions” to the housing crisis, offering solutions in attics, basements and backyards. By offering new financing options and a library of pre-approved designs, the city is making it easier for homeowners to build ADUs, the mayor added.
“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 in a statement.
Leila Borzog, the deputy mayor for housing and planning, similarly described ADUs as an “important tool” amid a “dire housing crisis,” offering an opportunity for homeowners to add space, bring in extra income and remain in their communities.
However, she said such units often feel “out of reach” for many New Yorkers at present, stating that the new set of tools will ensure that anyone who wishes to add an ADU will be able to do so.
“Whether you are interested in adding a new backyard cottage or converting an underused garage or attic into housing, we have resources to help guide you through the process,” Borzog said in a statement.
