R3A Zoning NYC

by | Last updated May 28, 2019 | Published on Aug 13, 2018 | NYC Zoning

R3A Zoning is a low density residential zoning contextual district in NYC. You can build single family or 2 family homes that are either detached or zero lot line in R3A.



The R3A Zoning District is a contextual sub district of R3 Zoning in NYC. R3A Zoning is mapped in The Bronx, Brooklyn, Queens, and Staten Island.

R3 Zoning Districts

R3 Contextual Districts


R3A Zoning Regulations

The New York City Zoning Resolution is complicated and quite in depth. In this article we will review some basic Zoning Codes with regards to residential zoning district R3A. This analysis does not assume to cover every possible issue, but provide a general overview of the zoning codes.

R3A Zoning Community Facility

R3A Zoning is a residential zone but Community Facility uses are allowed in R3 zones. In the instance of a community facility the zoning calculations may be different as community facilities can have alternate requirements.


R3A Zoning Specifications

Minimum Lot Size: Lot Area & Lot Width

Lot Size Detached or Zero Lot Line:

A Detached house has yards on all sides and does not touch any other buildings or houses. A zero lot line house touches one side property line but does not touch another house.

Minimum Lot width =25 Feet

Minimum Lot Area = 2,375 Sq Ft

R3A Floor Area Ratio (FAR):

Floor Area Ratio determines the floor area that can be built on the property. The floor area ratio is multiplied by the lot area.

FAR = .5

Attic Allowance 20% bonus

In R3A Zoning districts the FAR may be increased by 20% for floor area located under a pitched roof. This is not always possible to achieve.

Density Factor or Dwelling Unit Factor (DU) for R3A


R3A Building Heights: 

Perimeter Wall Height = 21 Feet

Building Height = 35 Feet

Yard Requirements for R3A

Front Yard = 10 Feet minimum

Rear Yard = 30 Feet

Side Yards = 8 Feet


R3A Zoning Example

Here is an example zoning analysis. Be aware that zoning is complicated and I am only addressing the basics here. I assure you there are many additional issues and variations to consider beyond this example.

R3A Example Lot

Lets assume we have a 40 foot wide and 100 foot deep property in an R3A Zoning District in The Bronx on an interior lot.

Zoning Floor Area/ Floor Area Ratio (FAR)

So the floor area ratio is .5. The FAR is a ratio that determines how many square feet you can build on the property. You simply take the property size and multiply it by the FAR.

In this example we have:

FAR of .5

Lot Size of 40 feet x 100 feet.

Zoning Floor Area = Lot Area X FAR

Lot Area = 40 x 100

Lot Area = 4,000 sq ft

FAR = .5

Zoning Floor Area = 4,000 sq ft x .5

Zoning Floor Area = 2,000 sq ft

There is a zoning Bonus for Attic allowance of up to 20%. Attic allowance is a little complicated, you will not always be able to maximize the attic allowance. We will assume that we can maximize the attic allowance for this example.

Zoning Floor Area with Bonus 2,400 sq ft

So we can build a 2,400 sq ft house.

How may families can we have on our R3A lot.

Zoning regulates the maximum number of residential units you can put in a building.

Multifamily is not allowed in R3A. Two families would be the maximum.

R3A Zoning Example Conclusion

In this example we are proposing to develop a 2 family house of 2,400 square feet. The buildings would be detached, and will need parking for every family.


R3A Zoning in NYC

As an architect I study Zoning Codes closely, but these are complicated and quite involved issues. In this article we reviewed some of the basic concepts with regards to the R3A Zoning Districts. This post does not assume to cover every possible issue or condition, but provide a general overview of the topic.


Thank You for reading our post on R3A Zoning in NYC.

I hope this was helpful. You can leave questions or comments below. If you want to discuss a specific project or want help with zoning review please feel free to contact Fontan Architecture directly. We will be happy to help.


Jorge Fontan
Jorge Fontan

This post was written by Jorge Fontan AIA a Registered Architect and owner of New York City architecture firm Fontan Architecture. Jorge Fontan has earned 3 degrees in the study of architecture including two degrees from the City University of New York and a Masters Degree in Advanced Architectural Design from Columbia University. Jorge has a background in construction and has been practicing architecture for 15 years where he has designed renovations and new developments of various building types.

  • Mark A says:

    Great post!…very useful information. I have a 50X220ft lot in an R3A in Staten Island. Am I understanding correctly that I can build a max of two structures on this site? Can each be a two family home then? Or could it be possible to build a townhome style structure with 4 or 5 units using the depth?

    • You cannot build multifamily buildings in R3A but you can subdivide this into smaller lots and build houses. If you are interested in discussing the development, give our office a call at (212) 321-0194.

  • Parvinder Kaur-Ubhi says:

    Hi, Jorge, I have a house in flushing, lot size is 47.50 feet wide and 100 feet long. Can I build 2 single family semi detach homes or 2 semi detach 2 family homes?

  • Prof. Khan says:

    I am purchasing a lot 19′ x 141′ in Howard beach area, it’s zone R3A
    Commercial Overlay: can I build a two family house with basement in it?

    • Hi Prof. Khan,
      Your lot is narrow by the typical R3A standards. I would need to review a survey to determine the feasibility. The house may end up being quite narrow. If you are interested in a zoning analysis, please call my office at (212) 321-0194.

  • Amy Doerzbacher says:

    Hi Jorge,
    I own a R3A single family ranch house with attached garage on a lot 74 ft wide by 126 ft deep. If I want to replace it with a two-family house, how large could it be? Would it have to be a single dwelling, attached?

  • Nancy Pezzolla says:

    Hi Jorge, can an R3A one family hi ranch be converted to a 2 family – it has a garage and a driveway – if it can be converted about how much does it cost?

    • R3A does allow two family houses, but zoning calculations would have to be done to determine the dwelling unit factor and all pertinent zoning matters to verify that the conversion can be done legally.

  • Syed Chowdhury says:

    20 x 100 ft
    R3A zoning area
    Is it possible to build a 2 family home
    Is the land has enough square footage to be a R3A zoning lot
    Please reply me when you get a chance

  • Jacky Zhen says:

    Empty Lot For Sale In Hamilton Beach. R3A Zoning
    Howard Beach
    1,398 sqft
    Can I build a single family house (4 bed rooms, 2 bath rooms, kitchen, living room and drive way) on this land?

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