NYC's ADU for You: Check Your Lot, Pick a Plan, and File in DOB NOW

Photo: "Roof for Two" by Anna Morrison Architect and Leonardo Leiva Rivera, via HPD, courtesy of the architects. Brick Underground.

New York City's housing agency HPD partnered with WXY architecture and urban design to launch ADU for You, a free web platform that went live in March 2026. The tool is designed to lower the activation energy for homeowners who want to add a backyard cottage or a basement unit to their property but do not know where to start. In one session, a homeowner can check lot eligibility by address, browse a curated library of pre-approved designs with rough cost estimates, and get a roadmap for opening a permit application in DOB NOW: Build.

"Our objective was to make that as simple as possible," said Adam Lubinsky, a principal at WXY. The platform grew out of Local Law 127 of 2024, which authorized the city to create a pre-approved plan program so that approved designs could move through the Department of Buildings faster than a custom filing.

What the eligibility check actually tells you

The first screen on housing.hpd.nyc.gov/adu asks for a street address. The tool cross-references the parcel against zoning maps, flood zone designations, landmark and historic district boundaries, and lot size minimums. Properties that clear those filters get a green result and a link to the plan library. Properties that do not clear them get a specific reason, which often points to a workaround or a variance pathway. For the majority of eligible lots, the platform currently shows the strongest concentrations in southeast Queens, including ZIP codes 11428 (Queens Village), 11429 (St. Albans), and 11419 (South Richmond Hill), as well as several Staten Island neighborhoods where detached one-family and two-family homes on full lots are common.

Wil Fisher, a principal at Unit Two Development, a Queens-based firm that designed two of the pre-approved backyard units, said that he has been fielding a rising number of inquiries since the site launched. "We're getting quite a lot of calls," he said. Flood zones and landmark districts remain the two most common disqualifiers, and homeowners who fall into those categories should review the DOB ADU page for exception pathways that are still being developed.

The plan library and the budgeting slider

If your lot qualifies, the platform takes you to a gallery of 11 architect-designed units. The designs span a wide range of typologies and price points. At the lower end, a 343-square-foot studio by ANE Design LLC is priced starting around $85,000 installed. At the upper end, larger two-bedroom configurations from other firms approach $650,000. Among the most-viewed entries is "Roof for Two," a two-unit rooftop concept by Anna Morrison Architect and Leonardo Leiva Rivera, and a 444-square-foot studio by VL Architects that fits on a standard Brooklyn or Queens attached lot. Each listing includes a floor plan, an exterior rendering, a construction cost range, and architect contact information. Fisher of Unit Two Development noted that the two designs his firm submitted are among the most frequently requested because they were sized for the typical southeast Queens backyard footprint.

A cost estimate slider lets homeowners enter a target budget and filter the library accordingly. The platform also displays a borough-wide map showing parcel density by neighborhood so that homeowners can see which areas have the densest concentration of eligible lots near them. Keep in mind that pre-approved means the architectural and structural plans have already passed DOB review for a standard installation; it does not mean you skip plan examination entirely. Your specific lot conditions, including foundation type, utility connections, and any site-specific variances, still require a licensed architect or engineer of record to certify the plans for your address before the permit is issued.

What filing in DOB NOW: Build actually involves

Local Law 127 of 2024 established the legal framework for ADUs in New York City, including the pre-approved plan program. When you are ready to file a permit, you do so through DOB NOW: Build, the city's online permitting portal. The job type is either an Alteration with Change of Occupancy (Alt-CO-GC) for an existing structure being converted or expanded, or a New Building-GC filing for a freestanding detached unit. Inside DOB NOW, navigate to the PW1 tab and look for the Ancillary Dwelling Unit section; that section triggers the ADU-specific review track, which is intended to be faster than a standard alteration review for properties using a pre-approved design.

The baseline rules under LL127 cap an ADU at 800 square feet. Owner-occupancy is required at initial occupancy, meaning the homeowner must reside on the property when the ADU is first rented out or occupied. A separate entrance that does not require passing through the primary dwelling is mandatory. One important zoning note: if you own a two-family home and add an ADU, the property legally becomes a three-family dwelling and falls under the Multiple Dwelling Law, which brings additional fire safety and habitability requirements. Separately, Local Law 80 of 2026, which took effect on April 9, 2026, added a pathway for cellar ADUs in one-family homes under 1RCNY 105-08(d)(4); this expands the basement conversion option that previously applied primarily to two-family homes. The LL126 pilot program, which targets affordable ADUs in buildings with six or more units, is still awaiting DOB rule promulgation and is not yet accepting applications as of late June 2026.

If you are modeling the rental income potential of a backyard unit or basement apartment in your neighborhood, the A-du rental map aggregates current listing data by ZIP code so you can see median asking rents and vacancy trends before you commit to a design budget.