ADU Regulations — New York, NY
Governed by ZR § 23-02. Last verified June 2, 2026.
All Areas
| Requirement | Value | Conditions / Exceptions | Source |
|---|---|---|---|
| Max Size Sqft | 800 | Whichever is less: 800 sq ft or 30% of principal building floor area Exception: None | ZR § 23-02 |
| Number Per Lot | 1 | One accessory dwelling unit per residential lot Exception: None | ZR § 23-02 |
| Owner Occupancy Required | True | Owner must occupy either the principal dwelling or the accessory dwelling unit Exception: None | ZR § 23-01 |
| Parking Spaces Required | 1 | Required unless waived by zoning district or on-street parking availability Exception: Parking may be waived in certain transit-rich areas | ZR § 23-02 |
Official Code Language (4 sections)
Pursuant to ZR § 23-02, applicable to all zoning districts, the maximum floor area of an accessory dwelling unit (ADU) shall not exceed 800 square feet.
Under ZR § 23-02, applicable to all zoning districts, no more than one accessory dwelling unit may be located on a single zoning lot.
As per ZR § 23-01, applicable to all zoning districts, the owner of the property must occupy either the principal dwelling or the accessory dwelling unit.
In accordance with ZR § 23-02, applicable to all zoning districts, at least one off-street parking space must be provided for the accessory dwelling unit.
Permit Requirements
- When required
- all ADUs require a permit from NYC Department of Buildings
- Fee
- — Permit fee based on construction cost; varies
- Where to apply
- NYC Department of Buildings
Verified June 2, 2026
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Frequently Asked Questions
How large can I build my ADU?
- The maximum size is 800 square feet (ZR § 23-02). - This limit applies in all zoning districts. - The square footage includes all interior living space.
Do I have to live on the property if I rent out the ADU?
- Yes, owner occupancy is required (ZR § 23-01). - You must live in either the main house or the ADU. - You cannot be a non-resident landlord.
Can I build more than one ADU on my lot?
- No, only one ADU per lot is allowed (ZR § 23-02). - This rule applies to all zoning districts. - Even if your lot is large, you cannot build a second ADU.
Do I need to provide parking for the ADU?
- Yes, at least one off-street parking space is required (ZR § 23-02). - The space must be reserved for the ADU resident. - This requirement is mandatory in all zones.
Sources
Data last verified: June 2, 2026
See how this works nationally: ADU Rules by State
This is an informational summary, not legal advice. Verify current requirements with New York Planning Department .
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