We found all(*) the ADU filings in NYC!

Chris

27 Dec 2025 — 3 min read

Total count: 13

Last updated: 12/26. (*) Data: Filings for new buildings since June 2025

With the City of Yes, NYC legalized ancillary dwelling units (ADU, in other cities usually called accessory dwelling units). And while the rollout has been messy, it looks like we're finally seeing action: As of Dec 26, 2025, we're counting at least 13 ADUs in filings for new buildings. As we update this, we'll also include alterations to existing buildings.

In the article, we give you key insights and lessons. The appendix will give you the full data, so you can investigate yourself. You can also find the list online, at https://citytracker.ai/results/public/filings_adu

But... what is an ADU? The image below gives you an idea of the options. The general idea is that, if you own a single or two-family building, you might now be allowed to construct such units or convert your garage into one.

How do we detect new ADUs? Before going into details, it's important to distinguish terms for NYC applications:

Filing: The initial request, for example "new building"
Permit: A specific task, e.g. "install a fence as part of the filing"

Here, we mostly look at filings, because they give us the earliest signal. Since filings contain a comment, we can search for terms like "ADU". We then manually cross-check and validate the results.

We find a total of 13 ADU filings. The trend seems to be accelerating, with the majority being filed in October 2025 and after.

Staten Island dominates, with 9 out of 11 filings, see map:

(map from https://citytracker.ai/results/public/filings_adu)

How do these ADUs look?

Type of ADU: First floor or higher=4, Side/rear=2, Basement=2, Unclear=5
Filing Status: Permit Entire ("ready to fill for permits") or approved=8, Objections=3, On hold=1, Incomplete=1
Size: Between 365 sqft and 1,162 sqft, median=522.

Not all these filings will result in completed ADUs. So far, we don't yet have detailed data telling us why there were issues, but we'll check in and get more information about the filings and future permits as they happen.

We do, however, get zoning documents with more information for lots of these applications (see renderings below).

Summary

The ADU revolution has started in NYC, for real. We're at 13 filings, and the trend for new filings is accelerating. Since ADUs are new, and the exact rules are unclear, we expect lots of issues: Filings will get rejected, resubmitted, or abandoned.

Appendix

Renderings

Full data

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