Permit Required? Required
Typical Fee Range $200–$2,500 (Application & Filings) Includes $200 initial fee for Plus One program; total fees calculated on project valuation and DOB NOW filing types.
Fee Method Valuation-based
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What's Required in New York City

  • Maximum size of 800 square feet for detached backyard cottages (City of Yes 2026 rules).
  • Must be located on a lot with an existing one- or two-family home.
  • Property owner must occupy either the primary residence or the ADU.
  • Basement ADUs must have a minimum ceiling height of 7 feet and comply with flood zone restrictions.
  • Must be located outside of FEMA Special Coastal Risk Districts or 2050 Stormwater Flood areas.
  • Fire Department (FDNY) access must be maintained to the rear of the property for detached units.

How to Get a ADU Permit in New York City

1

Step 1: Zoning Verification

Confirm lot eligibility under the 'City of Yes for Housing Opportunity' zoning amendments.

2

Step 2: Hire a Registered Professional

A licensed Architect or Engineer must prepare and seal the construction documents.

3

Step 3: DOB NOW Filing

Submit the application through the 'DOB NOW: Build' portal for plan review.

4

Step 4: Permit Issuance

Pay all applicable filing fees and obtain the official work permit to begin construction.

5

Step 5: Inspection & Sign-off

Schedule final inspections and obtain a Certificate of Occupancy or Letter of Completion.

Frequently Asked Questions

Yes, under the 2026 City of Yes rules, detached ADUs up to 800 sq ft are permitted on single-family lots.
The program application is $200, but total DOB filing fees vary based on construction costs (approx. $15 per $1,000).
Yes, the homeowner must live on-site in either the main house or the newly created unit.