ADU Rules: Calverton vs Islip
How do adu rules rules compare between Calverton, NY and Islip, NY?
Calverton and Islip have similar restriction levels.
Calverton, NY
Suffolk County
Accessory apartments (ADUs) are legal in every Suffolk County town under varying rules. Most towns require owner-occupancy of the primary dwelling, a minimum lot size (often 7,500-20,000 sq ft), a rental permit, and one off-street parking space for the ADU. Internal conversions and attached ADUs are most commonly permitted; detached ADUs are more restricted.
View full Calverton rules →Islip, NY
Suffolk County
Islip allows accessory apartments through its Accessory Apartment Permit program under Town Code Chapter 68, Article XXIII. One ADU per owner-occupied single-family home is permitted with an annual renewable permit from the Building Division.
View full Islip rules →Key Facts Comparison
| Fact | Calverton | Islip |
|---|---|---|
| Owner-Occupancy | Required in most Suffolk towns | - |
| Permit | Renewable every 2 years typical | Annual renewal |
| Septic | Suffolk DHS approval, I/A OWTS required | - |
| Size | 300-650 sq ft typical cap | - |
| Owner-Occupied | - | Required |
| Max Size | - | 650 sq ft |
| Min Lot | - | 10,000 sq ft |
Highlighted rows indicate differences between cities.
Calverton FAQ
Can I rent my basement as an ADU?
Only with a town accessory-apartment permit, proper egress, ceiling height, and DHS septic approval. Illegal basement apartments are a major enforcement target.
Who enforces this in Suffolk County?
Suffolk County code enforcement at (631) 853-4000 handles complaints.
Islip FAQ
Can I build an ADU on my property in Islip?
Town of Islip allows accessory apartments (ADUs) within single-family dwellings as a conditional use with ZBA approval after public hearing. Minimum lot: 7,500 sq ft and 75 ft wide. ADUs cannot be located in accessory structures (detached sheds, garages). Owner must occupy main or accessory...
What are the size limits for an accessory dwelling unit in Islip?
ZBA Approval: Required after public hearing. Min. Lot: 7,500 sq ft, 75 ft wide. Detached ADU: PROHIBITED — must be in main dwelling. Owner Occupancy: Required.
Compare other topics
See how Calverton and Islip compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool