ADU Pass
Babylon
ADU Pass helps homeowners in Babylon, Suffolk County, New York navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
Suffolk County — county ADU rules and overlays
County ADU ordinance
Suffolk County, NY (eastern Long Island, 1.5M residents) does not have its own countywide ADU ordinance with broad land-use authority over its 32 towns and 33 incorporated villages. Under New York town-law structure, ADU permissibility is set by each Town (Babylon, Brookhaven, Easthampton, Huntington, Islip, Riverhead, Smithtown, Southampton, Southold, Shelter Island) and each incorporated village. The state's Plus One ADU Program (HCR) provides up to $125,000 per ADU as a forgivable loan/grant for income-eligible homeowners; participation in Plus One is voluntary at the town level. Suffolk County participates in regional housing planning through the Suffolk County Department of Economic Development and Planning, which produced an ADU policy white paper but does not have direct land-use authority.
State-floor overlay: New York has not enacted comprehensive statewide ADU preemption. The Plus One program incentivizes but does not require local adoption. ADU rules vary materially by town across Suffolk.
County regulatory overlays
Suffolk County administers flood-hazard, and (where mapped) coastal, wildland-fire, historic, and airport overlays that shape ADU project feasibility. The most consistent overlay across the county is FEMA NFIP floodplain regulation; other overlays apply to specific geographies inside the county.
- FEMA NFIP Special Flood Hazard Areas in Suffolk County — A new ADU in a mapped SFHA must be elevated to or above the Base Flood Elevation; cost impact on the project is often material.
- Historic districts and individually-listed historic resources
New York state — ADU law and programs
State financing programs
New York operates the Plus One ADU Program, a state-funded grant initiative administered by NYS Homes and Community Renewal (HCR) that finances new ADU construction and the legalization of existing unpermitted units for low- and moderate-income homeowners. The program was capitalized at $85 million over five years by the FY2022-2023 NYS Capital Budget; approximately $59 million had been awarded to local government and non-profit subrecipients across the first two rounds. A separate NYC-administered Plus One ADU pilot (run by HPD) layers additional grant + loan dollars on top within the five boroughs.
State housing programs
Beyond the Plus One ADU funding stream, New York's statewide ADU policy footprint is concentrated in HCR's Plus One technical-assistance and pre-development resources for subrecipient localities. The state does not currently operate a statewide pre-approved ADU plan catalog, statewide impact-fee waiver, or statewide streamlined-review timeline floor — those tools sit at the municipal level (notably the City of Yes for Housing Opportunity package adopted by NYC in late 2024). New York's 'City of Yes' is a NYC zoning text amendment, not a state program, and is therefore not state-primary.
- Plus One ADU technical assistance — Bundled with the Plus One grant award — HCR-funded TA for subrecipients on ADU project scoping, contractor selection, design review, and homeowner outreach. Layered with local code-compliance support.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Code
- 11702
Post Office
- 110 Cooper St, 11702