ADU Document Checklist

Proving current ownership of the property

Shows existing legal use and occupancy classification of your building

Licensed surveyor boundary and topographic survey of your lot

Required for detached ADUs to inform foundation design

Required for basement and cellar conversions (all below-grade habitable spaces)

Required for buildings constructed before 1985 undergoing renovation

Must be stamped and signed by a NYC DOB-registered Registered Design Professional (RDP)

Load calculations, foundation design, and structural details

HVAC, electrical panel sizing, plumbing layout, and connections

Fire suppression system design as required by NYC Building Code

NYC Energy Conservation Code compliance showing insulation, HVAC efficiency, etc.

FAR calculations, setback compliance, yard coverage, and lot coverage analysis

NYC DEP confirmation that local sewer capacity supports the new unit

Both FEMA flood maps and DEP drainage maps for your property location

Reference number from the HPD Pre-Approved Plan Library catalog

How the pre-approved plan is adapted to your specific lot conditions

Full application completed in the DOB NOW: Build portal

Every document from previous phases uploaded to the DOB NOW application

DOB filing fees vary by project scope; minimum is $130 for the application

Property owner must sign or authorize the filing (can be done digitally)