Question 1

What is an ADU?

Accepted Answer

An Accessory Dwelling Unit (ADU) is a smaller, self-contained residential unit on the same lot as a primary home. Under NYC Local Laws 126 and 127 of 2024, homeowners can now legally create ADUs as basement or cellar conversions, garage conversions, or new detached structures in their backyards.

Question 2

Is my property eligible for an ADU?

Accepted Answer

Eligibility depends on several factors: your property must be in an eligible zoning district (most R1 through R5 residential zones), the lot must be owner-occupied with 1-to-3 family housing, and there must be sufficient lot area and setback space. Use our free eligibility checker for an instant assessment.

Question 3

What zoning districts allow ADUs?

Accepted Answer

ADUs are permitted in most low-density residential zoning districts across NYC, including R1, R2, R3, R4, and R5 districts. These cover large portions of Brooklyn, Queens, Staten Island, and the Bronx.

Question 4

Do I need to live on the property?

Accepted Answer

Yes. Local Laws 126 and 127 require that the property be owner-occupied. The homeowner must reside in either the primary dwelling or the ADU itself.

Question 5

Can I build an ADU in my basement?

Accepted Answer

Yes, basement and cellar conversions are one of the most popular and cost-effective ADU types. The space must meet specific habitability requirements including minimum ceiling height, adequate natural light and ventilation, proper egress, and flood-proofing if in a flood zone.

Question 6

How much does it cost to build an ADU in NYC?

Accepted Answer

Costs vary widely. Basement or garage conversions typically range from $100,000 to $250,000. Detached new-construction ADUs range from $200,000 to $650,000+ depending on size, finishes, and site conditions.

Question 7

Does an ADU increase property value?

Accepted Answer

Yes, ADUs typically increase property values significantly. National studies show ADUs add 20-30% to a propertys assessed value, and in NYCs high-cost market the impact can be even greater.

Question 8

What are HPD pre-approved plans?

Accepted Answer

HPD has partnered with architecture firms to create pre-approved ADU designs that have already been reviewed and approved by the city, significantly streamlining the permitting process.

Question 9

Do I need a permit to build an ADU?

Accepted Answer

Yes, all ADUs require permits from the NYC Department of Buildings (DOB). You will need a DOB work permit, and depending on the scope, possibly plumbing, electrical, and mechanical permits as well.

Question 10

How long does the permitting process take?

Accepted Answer

With HPD pre-approved plans, permitting can take as little as 2-4 months. Custom designs typically require 4-8 months. Total timeline from start to move-in: 6-16 months depending on complexity.

Question 11

Can I rent out my ADU?

Accepted Answer

Yes, ADUs can be legally rented out at market rate. There are no rent stabilization requirements for new ADUs. Rental income can significantly offset mortgage costs, property taxes, and construction investment.

Question 12

How much rental income can I expect?

Accepted Answer

A studio or 1-bedroom ADU in Brooklyn or Queens can rent for $1,500-$2,500/month, while a 2-bedroom can command $2,200-$3,500/month. Use our ROI Calculator for a personalized estimate.

Question 13

What about parking requirements?

Accepted Answer

Under the new law, building an ADU does not require any new parking spaces, even if you convert an existing garage. This single change dramatically expands the number of eligible properties.

Frequently Asked Questions

Eligibility

Costs

Plans

Permitting

Construction

Rental Income

Ready to explore your ADU options?