How to Check if Your NYC Property Qualifies for an ADU in 30 Seconds

the number one question NYC homeowners have right now: can I build an ADU on my property? with the city's new ADU tools and the Plus One financing program reopening, interest is at an all-time high. but figuring out eligibility used to mean hours of cross-referencing zoning maps, flood zone databases, and DOB regulations.

we built the nycadu.com eligibility checker to answer that question in about 30 seconds. here's exactly how it works, step by step.

before you start: what the tool checks

our eligibility checker analyzes your property against every major ADU qualification factor under Local Laws 126 and 127 of 2024:

• zoning district -- ADUs are allowed in most R1 through R5 residential zones, but there are exceptions in certain special districts.
• building type -- your property must be a one- or two-family detached, semi-detached, or semi-attached home.
• flood zone status -- subgrade (below-ground) ADUs cannot be built in high-risk flood zones identified by FEMA or DEP mapping.
• historic district restrictions -- backyard ADUs face limitations in landmarked historic districts.
• lot coverage -- your lot needs enough open space to accommodate an ADU within zoning setback and coverage requirements.
• Special Coastal Risk District -- properties in these areas face additional restrictions.

step 1: go to the eligibility checker

head to nycadu.com/check. you'll see a clean, simple interface with one main input: your property address. no account needed, no email required. just your address.

step 2: enter your NYC address

type in your full property address. the tool uses NYC's property database to look up your lot, so be as specific as possible. include the house number, street name, and borough. for example:

• 123 maple street, queens
• 456 bay ridge avenue, brooklyn
• 789 victory boulevard, staten island

the address field has autocomplete, so it'll start suggesting matches as you type. select your property from the dropdown to ensure the right lot gets analyzed.

step 3: select your borough

confirm your borough from the selector. this helps narrow the lookup and ensures we pull the correct property record from the city's database. the five boroughs each have different ADU landscapes:

borough	ADU-eligible lots (est.)	average lot size
queens	28,400+	larger lots, strong backyard ADU potential
brooklyn	21,000+	tighter lots, basement conversions popular
staten island	11,500+	largest lots in the city, lowest build costs
bronx	6,100+	affordable properties, high ROI potential
manhattan	limited	very few qualifying one/two-family homes

step 4: review your results

within seconds, you'll get a detailed eligibility breakdown. here's what each result means:

result: eligible for ADU

your property meets the basic zoning, lot, and flood zone requirements for at least one type of ADU. the results will specify which types you likely qualify for:

• backyard cottage (detached) -- a new standalone structure in your rear yard
• basement conversion -- converting existing below-grade space into a legal dwelling unit
• garage conversion -- turning an attached or detached garage into living space
• attic conversion -- converting attic space in a one-family home (adds a unit, making it two-family)

result: conditionally eligible

your property may qualify, but there are factors that need professional review. common conditions include:

• you're in a flood zone that allows above-grade ADUs but not basement conversions
• your lot is in a historic district where backyard structures need Landmarks Preservation Commission approval
• your two-family home could add an ADU, but it may trigger Multiple Dwelling Law requirements unless separated by a fire wall

result: not currently eligible

don't panic -- this doesn't always mean never. common reasons for ineligibility include:

• multi-family building (3+ units already)
• attached rowhouse without qualifying lot configuration
• Special Bay Ridge District restrictions for backyard ADUs
• high-risk flood zone for subgrade conversions

step 5: explore your next steps

after getting your result, the tool suggests specific next actions based on your situation:

• if eligible: browse pre-approved plans, run the ROI calculator, or apply for Plus One financing
• if conditionally eligible: book a consultation to get professional guidance on your specific situation
• if not eligible: check if a different ADU type might work, or explore the FAQ for alternative options

what our checker does differently than the city's tools

the city's new ADU for You platform has a lot of great resources, but it doesn't offer a single-address instant eligibility check. to figure out eligibility through official channels, you'd need to:

1. look up your zoning district on ZoLa (the city's zoning and land use map)
2. check your flood zone on FEMA's flood map or DEP's drainage area map
3. verify you're not in a historic district through LPC's database
4. calculate your lot coverage and setback requirements manually
5. determine if you're in the Special Coastal Risk District

our tool does all of that in one step. we pull data from multiple city databases and cross-reference them against the ADU eligibility rules in Local Laws 126 and 127.

common questions about the eligibility checker

does the tool cost anything?

no. the eligibility check is completely free, no account required.

is the result a guarantee I can build?

no. our tool provides a preliminary analysis based on publicly available property data. you'll still need a licensed architect or engineer to do a full site assessment and file with DOB. but it gives you a strong starting point so you know whether it's worth investing time and money in the next steps.

how accurate is it?

we use the same property records and zoning data that DOB and HPD use. the main variables that could change your result are site-specific conditions (like existing structures, soil conditions, or utility access) that require a physical inspection.

can I check a property I don't own yet?

yes. if you're considering purchasing a property and ADU potential is a factor, you can check any NYC address. this is especially useful for investors evaluating properties in queens or staten island where ADU-eligible lots are most common.

the 30-second version

here's the tl;dr:

1. go to nycadu.com/check
2. type your address
3. select your borough
4. get your eligibility result
5. follow the recommended next steps

that's it. no signup, no phone calls, no waiting. the city just made building ADUs easier with their new tools. we made figuring out whether you should build one even easier.

check your property now: nycadu.com/check