Methodology: how the PiedWatch NYC pied-à-terre list is built
What the list shows
PiedWatch estimates which New York City properties may be subject to the non-primary residence surcharge — the pied-à-terre tax associated with Mayor Zohran Mamdani. Phase 1 of the law applies to tax class 1 homes with a market value of $5 million or more and to co-op/condo units with a market value of $1 million or more.
This is an estimate from public data, not a determination by the NYC Department of Finance. DOF determines primary residence from private filings; PiedWatch only screens for public indicators that a property is not anyone’s primary residence.
Phase-1 surcharge rates
Phase 1 took effect 2026-07-01. The surcharge is a flat rate on the property’s full DOF market value: the tier rate applies to the entire value, not just the portion inside the bracket.
| Tax class | FY27 market value | Rate |
|---|---|---|
| Class 1 — 1–3 family homes and small condos (classes 1, 1A, 1C) | $5M – $15M | 0.8% |
| over $15M – $25M | 1.05% | |
| over $25M | 1.3% | |
| Class 2 — co-op and condo units (classes 2, 2C) | $1M – $3M | 4.0% |
| over $3M – $5M | 5.25% | |
| over $5M | 6.5% |
Phase 2 (2028) changes co-op and condo valuation to a comparable-sales basis, replacing DOF’s imputed unit values.
Sources
- DOF FY27 supplemental market value roll (published 2026-07-24, open for public inspection until 2026-12-31): every NYC parcel with its new sales-based full market value (FMV), owner of record, tax class, and building class. 684,619 tax class 1 records and 275,092 tax class 2 records.
- DOF Property Abatement Detail (NYC Open Data, dataset rgyu-ii48): recipients of the co-op/condo abatement, which by law is only available to owners who use the unit as their primary residence. We use the current snapshot (most recent extract).
- DOF Property Exemption Detail (NYC Open Data, dataset muvi-b6kx): residency-requiring exemptions — veterans (1010, 1011), senior citizen homeowners / SCHE (1015), disabled homeowners / DHE and disabled crime victims (1016, 1019). The STAR exemption no longer appears on the roll (it was converted to a New York State income-tax credit).
- PLUTO (NYC Open Data, dataset 64uk-42ks): parcel centroids (latitude/longitude) keyed by BBL.
- Photos: Wikimedia Commons geosearch (freely licensed), Mapillary (CC BY-SA, when enabled), and USGS NAIP aerial imagery (public domain, via Microsoft Planetary Computer). Each photo carries its attribution on the property page.
Historic tax photos: the NYC Municipal Archives photographed nearly every city parcel for tax purposes in the 1940s and again in the 1980s. When the lot’s photo exists in the Archives collection, the property page displays it inline from the Archives-served image host with attribution, and links to the full viewer on 1940s.nyc. Images © City of New York; bulk/commercial reuse requires Archives permission.
Ownership records: property pages show the most recent deed recorded in ACRIS (NYC Open Data datasets 8h5j-fqxa, bnx9-e6tj, 636b-3b5g) — its date, price, and recorded parties — plus the building’s HPD registration contacts (datasets tesw-yqqr, feu5-w2e2) when the building has an HPD registration. New York State does not publish the officers or members of an LLC, so officer names cannot be listed; the parties and addresses shown are exactly as recorded in the public record.
The screen
A roll row becomes a surcharge candidate when its FMV crosses the phase-1 threshold for its tax class. A candidate is listed as a likely non-primary residence when both are true:
- No current co-op/condo abatement (joined on the unit PARID for condos, and on PARID + co-op account number for co-ops), and
- No residency-requiring exemption on the parcel.
This follows the NYC Comptroller’s Fiscal Note 2-2026 methodology. Owner names that match LLC/INC/CORP/CORPORATION/TRUST/LP/LLP/LIMITED are flagged as corporate/trust ownership for context; that flag does not affect the screen.
Limitations
- Abatement and exemption data lag real life; a primary resident who never claimed the abatement will appear on this list.
- The roll is a proposed supplemental roll, subject to change until the final roll.
- Primary residence is a legal determination only DOF can make.
Corrections
Are you the primary resident of a listed property, or is a listing otherwise wrong? Email [email protected] with the BBL and details and we will review it against the public record.