R10A Zoning NYC
R10A Zoning in NYC is high density residential zoning district. This is contextual zoning which means following the Quality Housing Program requirements. R10A Zoning is found in Manhattan on the Upper East Side and Upper West Side.
This post will only be addressing R10A Zoning, here is a list of all the other R10 Zoning Districts.
R10 Zoning Districts
Basic R10 District:
R10 Contextual Districts
Commercial Zoning with R10A Residential Equivalent
R10A Zoning NYC
What Is R10A Zoning?
R10A Zoning is considered “high density” residential zoning. It typically has multifamily buildings that are often around 20 stories. In an R10A zone you must follow the Quality Housing Program zoning regulations.
Quality Housing Program R10A
The Quality Housing Program promotes shorter wider buildings that are typically larger in square footage then a tall skinny building. The Quality Housing Program is not to be confused with the Inclusionary Housing Program for affordable housing. The quality housing program is just another set of optional zoning regulations and has nothing to do with low income or affordable housing. The quality housing program typically will result in a larger building of a higher quality. There are more zoning floor area deductions in quality housing that would give you a boost to your total building size.
R10A Zoning Community Facility
R10A Zoning is a residential zone but Community Facility uses are allowed in all R10 zones. In the instance of a community facility the zoning calculations would be different. One can also build a mixed use building with both community facility and residential use.
R10A Zoning Commercial Overlay
Sometimes residential districts have commercial overlays. This means the zone is primarily residential but commercial use is allowed instead or you can have both as a mixed use building. Here is a link to an article we wrote on Commercial Overlays.
R10A Inclusionary Housing Program
Always check if your property is subject to requirements of the Inclusionary Housing Program. These are districts that have either optional and sometimes mandatory requirements for low income housing. Typically in these areas you provide 20% of your floor area for affordable units. There can be zoning penalties if you choose not to provide it. And zoning bonuses if you do.
R10A Zoning Regulations For Quality Housing
Minimum Lot width =18 Feet
Minimum Lot Area = 1,700 Sq Ft
Corner Lot = 100%
Interior or Through Lot = 70%
Floor Area Ratio (FAR):
FAR = 10
With Inclusionary Housing Bonus FAR = 12
680 – This is used to calculate how many apartments you can have. The total residential floor area is divided by this factor to get the maximum allowable number of dwelling units.
Building Base Height: This indicates a setback is required at these heights
Base Height = 60 Minimum / 125 Maximum
Base Height = 125 Minimum / 150 Maximum (155 With Qualifying Ground Floor)
Inclusionary Housing Base height
Base Height = 60 Minimum / 155 Maximum
Base Height = 125 Minimum / 155 Maximum
A setback is required in the base height range. Or this can be the maximum height of the building without a setback.
Overall Building Height: This is the maximum building height
Narrow Streeet Max Building Height = 185
Wide Street Max Building Height = 210 feet or 215 with Qualifying Ground Floor (21 Stories)
Inclusionary Housing Building Height
Narrow Street Max Building Height = 210 or 215 with Qualifying Ground Floor (21 Stories)
Wide Street Max Building Height = 230 feet or 235 with Qualifying Ground Floor (23 Stories)
Always check if your building is subject to Sliver Law zoning restrictions for properties less than 45 feet wide. The sliver law is an additional restriction on the height of the building and supersedes the typical building height requirements.
Corner Lot: No Yards Required
Interior Lot = 30 foot minimum rear yard required
R10A Zoning Example
Here is an example 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.
R10A Zoning Example Lot
Lets assume we have a 50 foot wide and 100 foot deep property in an R10A Zoning District on The Upper West side of Manhattan in on an interior lot on a wide street.
Building Foot Print:
First Lets start with Lot Coverage and Yards. We know we will need a minimum rear yard of 30 feet. That tells us we have 50 x 70 to build on, and we can cover 70% of the property. This works out well with a 3,500 sq ft area we can build on.
Zoning Floor Area/ Floor Area Ratio (FAR)
So the floor area ratio is 10. 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 10
Lot Size of 50 feet x 100 feet.
Zoning Floor Area = Lot Area X FAR
Lot Area = 50 x 100
Lot Area = 5,000 sq ft
FAR = 10
Zoning Floor Area = 5,000 sq ft x 10
Zoning Floor Area = 50,000 sq ft
So we can build a 50,000 sq ft building. This is the zoning square footage, the actual building will be a little bigger than that.
We said our building foot print would be 50 x 70. Or 3,500 per floor.
This will give us at least a 15 story building. Because the maximum base height is 150 feet we can have a setback on the top floor with a terrace.
How many apartments can we build on our R10A lot?
Zoning regulates the maximum number of residential units you can put in a building. In this apartment building we have 50,000 zoning square feet. We then take the zoning Area and divide by the Density factor.
Number Of Apartments = Zoning Floor Area ÷ Density Factor
Number Of apartments = 50,000 ÷ 680
Number Of Apartments = 73 we can round up in this case
Maximum Number Of apartments = 73
R10A Zoning Example Conclusion
In this example we are proposing to build a 50,000 sq ft building. The apartment building will be at least 15 stories tall and have a setback at least on the top floor. The Building will have a foot print of 50 x 70. It will have a maximum of 73 apartments but can have less as well.
Thank You for reading our Blog Post on R10A Zoning
I hope this was helpful. If you want to discuss a specific project with an architect please feel free to Contact Fontan Architecture. We will be happy to help.
Author Jorge Fontan AIA
This post was written by Jorge Fontan, a Registered Architect and owner of Fontan Architecture.