NYC Rear Yard Requirements Explained (and When They Shrink)

Short answer: A rear yard is the required open space at the back of your lot that you generally can't build on. NYC zoning requires a minimum rear yard depth in most residential districts, but there are situations, like shallow lots, corner lots, and certain building types, where that requirement shrinks or changes.

If you're planning an extension at the back of your house, the rear yard is often the first rule that limits you. Here's how rear yards work in NYC zoning, in plain English, and when the requirement gives you a little more room than you'd expect.

What a rear yard is

A rear yard is open space that runs along the rear lot line, the back edge of your property. Zoning requires you to leave this space open (unbuilt) to a minimum depth, measured from the rear lot line toward your building. The idea is to preserve light, air, and open space at the center of the block, the shared "backyard" space you see when you look at a block from above.

Because it's measured from the rear lot line inward, the rear yard effectively caps how far back your building, or your new extension, can go.

Rear yard vs. rear yard equivalent

You'll sometimes see the term "rear yard equivalent." That applies to special situations, like through lots (lots that run from one street to another with no traditional rear), where a normal rear yard doesn't fit the geometry. In those cases zoning substitutes an equivalent open-space requirement in a different location. If your lot is unusual in shape, this is a term worth knowing.

When the rear yard requirement shrinks

The required rear yard isn't the same in every situation. Several common circumstances can reduce or modify it:

• Shallow lots. If your lot is unusually shallow (short from front to back), the required rear yard can be reduced, because applying the full requirement would leave almost nothing buildable.
• Corner lots. Corner lots often don't have a traditional rear yard requirement in the same way, because of how they front on two streets. The rules for corners are genuinely different.
• Lower floors vs. upper floors. Some rules treat the space differently at different heights, so what's required at the ground level isn't always required all the way up.
• Building and use type. The required depth and how it's applied can depend on the type of building and district.

The exact depths and the precise conditions for each of these are set in the Zoning Resolution and depend on your district, so treat the above as the categories to check rather than a guarantee for your lot.

Why this matters for a rear extension

Most homeowners meet the rear yard when they try to extend the back of the house. Before you fall in love with a design, it's worth figuring out your required rear yard depth first, because it sets the hard line for how far back you can build. Sometimes you have more room than you thought (a shallow-lot reduction), and sometimes less (a deeper required yard than expected).

How to find your rear yard requirement

Your required rear yard is tied to your zoning district and your lot's shape. Find your district on the city's free zoning map (ZoLa), then check the rear yard rules for that district in the current Zoning Resolution, paying attention to any reductions for shallow lots or special provisions for corner and through lots. Because your lot's exact dimensions drive the answer, measuring matters.

Not sure how deep your rear yard has to be? Enter your address into Zohgo and it will help you understand your district's rear yard rules and how they affect a back extension, in plain English. Try Zohgo free at zohgo.ai.

This article is general information about how NYC zoning works, not legal or professional advice. Rear yard rules are detailed, depend on your lot and district, and change over time, so confirm the specifics for your property against the current Zoning Resolution or with a licensed professional before making decisions.