ADU guides · Updated October 2026

NYC ADU guides for homeowners.

The City of Yes ADU rules are new, and the details matter. Each guide answers the question up front, then covers the cases where it depends, with dated sources.

Can I build one?

Can I build an ADU on my NYC property?The eligibility checklist: building type, owner occupancy, zoning, historic and special districts.Read the guide Can I build an ADU in a flood zone in NYC?Which ADUs DEP's flood maps rule out, and the elevation rules for the rest.Read the guide

What about basements and permits?

Can I legalize my basement apartment in NYC?Building a new basement unit versus the Local Law 126 pilot for existing ones.Read the guide Do I need a permit to build an ADU in NYC?DOB NOW filing, job types, pre-approved plans and the certificate of occupancy.Read the guide

What does it cost and earn?

How much does an ADU cost in New York City?What little NYC cost data exists, what drives the price and where financing comes from.Read the guide How much rent can an ADU make in NYC?Current median rents by borough, rental rules and the Plus One rent restriction.Read the guide

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