NYC Property Due Diligence: The Complete Pre-Offer Checklist (20+ City Data Sources)

By NYC Property Intel · Updated June 3, 2026 · 31 min read

Before you make an offer on any NYC building, you should already know its open violations, tax liens, ECB judgments, rent-stabilization exposure, and looming local-law compliance bills. The problem: that data is scattered across 20+ official city data sources, so most buyers don’t find the deal-killer until attorney review or the closing table — after the money and leverage are gone. NYC Property Intel runs all 20+ sources in one query, so you find it before you bid.

TL;DR / Key Takeaways

  • NYC property due diligence is a pre-offer investigation of a building’s public records — violations, liens, ownership, rent regulation, and capital-expense risk — across 20+ city data sources (DOB BIS, DOB NOW, ACRIS, ECB/OATH, HPD Online, DHCR, ZoLa, DOF).
  • Violations and liens follow the property, not the seller. Open DOB/HPD violations and ECB/OATH judgments attach to the BBL — the buyer inherits them. A two-family carrying, say, $87,000 in unpaid ECB judgments can die at title — the buyer inherits every dollar.
  • Timing is leverage. Find a $50K facade liability at the offer stage and you reprice or walk for free; find it at closing and you’ve already paid for legal, inspection, and an accepted bid.
  • The data is fragmented by design. DOB alone runs two systems (legacy BIS + DOB NOW); checking only one misses entire classes of records.
  • This is due diligence, not a title search. It surfaces and flags public records. It does not replace a title search, an official DHCR rent-history request, or a physical inspection — and we say so on every check.
  • Run it as one AI query. Give NYC Property Intel an address; get one normalized risk profile across all 20+ sources, in plain English, with honest data-vintage stamps.

Data sources & last updated: Reflects NYC Open Data and city systems (DOB BIS, DOB NOW, ACRIS, ECB/OATH, HPD Online, DHCR, ZoLa, DOF) through June 2026.

Quick Answer: What NYC Property Due Diligence Actually Means

NYC property due diligence is the pre-offer investigation of a building’s public records — violations, liens, ownership, rent regulation, and capital-expense risk — across 20+ official city data sources (DOB BIS, DOB NOW, ACRIS, ECB/OATH, HPD Online, DHCR, ZoLa, DOF) to find deal-killing liabilities before you make an offer. It is due diligence, not a title search, an appraisal, or legal advice.

Here is the pain it solves. Because that data is so fragmented, material problems usually surface late — at attorney review or closing, after you’ve sunk money and emotion into a deal. An attorney can surface undisclosed FDNY standpipe violations on a $1.4M co-op at the eleventh hour; a buyer can turn up a dozen-plus open DOB/HPD violations days before closing — enough to force a multi-week delay, collapse the deal, and burn five figures in sunk legal and inspection fees. NYC Property Intel’s full due-diligence scan runs one address against all 20+ data sources at once, moving that discovery from contract or closing to before the offer.

What due diligence covers (and what it does not)

Pre-offer vs. pre-closing: why timing changes everything

Records are “spread across more than a dozen city agencies, each with its own database,” and the NYC Dept. of Buildings itself warns that relying on only one system can cause you to miss critical information. Find a $50K facade liability at the offer stage and you negotiate the price down or walk for free. Find it at closing and you’ve already spent on legal, inspection, and an accepted bid. Same data, very different leverage.

The honest limits: title search, DHCR rent history, physical inspection

The tool flags risk from public data — it does not replace three things, and we say so plainly:

That honesty is the point: knowing the data’s vintage and limits is what makes the answer trustworthy.

Why Due Diligence Has to Happen Before You Make an Offer (Not at Closing)

Here is the brutal math of NYC due diligence today: by the time your attorney or title company finds the problem, it is too late to do anything but lose money. Discovery happens at contract review or — worse — at the closing table, after you have already wired your deposit, paid legal fees, and emotionally committed to the deal. At that point you have three bad options: eat the cost, walk away and forfeit, or inherit the liability. The fix is structural. Move risk discovery to before you make the offer, when the price is still negotiable.

How an inherited ECB judgment dies at closing

Picture a two-family carrying $87,000 in outstanding ECB default judgments. The title company will not insure over them, the seller cannot pay them off, and the buyer’s deposit and months evaporate — a “dead deal.” And a dead deal is the good outcome: at least the buyer did not close. The worse version is a dozen-plus open DOB/HPD violations surfacing days before closing, forcing a multi-week delay that collapses the deal and burns five figures in sunk legal and inspection fees.

Violations and liens follow the property, not the seller

This is the part out-of-state buyers learn the hard way: open violations, OATH/ECB judgments, and liens attach to the BBL, not to the person who created them. You “step into the seller’s shoes.” ECB judgments remain enforceable for eight years and must be satisfied at or before closing. Worse, under Local Law 153 of 2017 an unpaid ECB judgment can be entered as a permanent DOF tax lien against the property — and for a small home (a private dwelling, or any building with three or fewer dwelling units) that conversion is automatic, with no dollar minimum. Larger buildings convert only above set thresholds (6–19 units at $30,000+, 20+ units at $60,000+). Either way the judgment attaches to the BBL and must be cleared before you can close.

What a repriced deal looks like when you find it early

Run NYC Property Intel’s full due-diligence scan on the address before you write the offer. In one query it surfaces DOF tax liens, ACRIS mortgages and lis pendens, and ECB/OATH judgments — the same encumbrances your title company would otherwise flag at closing. An $87,000 exposure stops being a deal-killer and becomes an $87,000 price reduction or a seller-cured condition.

One honest caveat, because it protects you: this surfaces and flags public-record liens — it is not a title search or a title certification. Use it to walk into the offer informed, then let your title company do the formal continuation search.

🔎 Run a free Risk Scan on any NYC address

See the open violations, liens, and judgments before you sign — not at the closing table. Enter one address and get a personalized flag summary across all 20+ city data sources.

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Where NYC Property Data Actually Lives (the Fragmentation Problem)

To truly vet one NYC building before you make an offer, you don’t search one database — you search more than a dozen, each with its own login, search logic, and jargon. NYC property records are, in the words of due-diligence practitioners, “spread across more than a dozen city agencies, each with its own database,” and a thorough review “relies on 20+ official city public record datasets”. Miss one and you miss the violation, lien, or regulatory flag that kills the deal at closing. That’s hours of manual cross-referencing per property — the root-cause pain that amplifies every other risk in this guide.

DOB BIS vs. DOB NOW: the two systems people forget to check both

This is the gap most buyers miss. The Department of Buildings runs two separate systems: DOB BIS (the legacy 1990s system holding older permits, violations, and Certificates of Occupancy) and DOB NOW (the current filing platform). Records did not all migrate. As the City itself warns, “relying on only one of these systems could cause you to miss critical information” (NYC Dept. of Buildings). A facade (LL11/FISP) or boiler record can sit in one system while you’re searching the other.

ACRIS, DOF, ECB/OATH, HPD Online, DHCR, ZoLa — what each holds

Run all 20+ sources in one step

Give NYC Property Intel an address; the property lookup resolves the canonical BBL, then every downstream tool — the violation check, the lien & encumbrance check, the ownership lookup, the rent-stabilization check, and more — runs against it. Ask a plain-English question; get one normalized risk profile before you bid. Our edge isn’t breadth alone (the new aggregators claim that too) — it’s natural-language AI querying plus MCP/agent access, and radical data-vintage honesty.

Data vintage and known limits (indexing lag, ~33% dobjobs drift)

Public data has real limits, and we disclose them rather than paper over them. DOB job-filing (dobjobs) data shows roughly 33% drift from Socrata and a 30–70 day violation-closure lag — a known, accepted limitation. NYC Property Intel surfaces and flags public records; it does not replace a title search, a formal DHCR rent-history request, or a physical inspection. Honest data vintage is part of the value: you know exactly how fresh each signal is before you act on it.

In a hurry? Skip the dozen logins and scan one address → — one query returns the same cross-agency profile that takes hours by hand.

Check 1: Building Violations — DOB, ECB & HPD

The single most expensive mistake a NYC buyer makes is checking one violation system and assuming it’s the whole picture. It isn’t. DOB violations, ECB/OATH judgments, and HPD violations live in separate databases that don’t talk to each other — and a violation that reads “resolved” in one can still owe a five-figure fine in another. A buyer can easily turn up a dozen-plus open DOB/HPD violations days before closing — enough to trigger a multi-week delay, a deal collapse, and five figures in sunk fees. Violations follow the property, not the seller — so whatever you miss, you inherit.

What is an ECB violation? An ECB (Environmental Control Board) violation is a penalty issued by the NYC Department of Buildings and adjudicated by the Office of Administrative Trials and Hearings (OATH). Unlike a standard DOB violation, an ECB violation carries a monetary fine — and under Local Law 153 of 2017 the City can enter an unpaid ECB judgment as a tax lien against the property: automatically for a private dwelling or any building with three or fewer dwelling units (no dollar minimum), or above set thresholds for larger buildings (6–19 units at $30,000+, 20+ units at $60,000+). Either way the unpaid fine attaches to the BBL, which is why “the DOB site says resolved” is dangerously incomplete.

How to check DOB violations and complaints

DOB data is split across two systems: legacy BIS (pre-2020 records) and DOB NOW (current filings). Checking only one misses an entire class of violations. Or skip the two logins — the violation check and the DOB complaint check scan both BIS and DOB NOW by BBL in one query.

How to check ECB violations (and why a “resolved” DOB violation can still owe an ECB fine)

Search OATH’s Hearings Division separately for open summonses and docketed judgments — a DOB condition can be cured while the OATH fine sits unpaid for years. Or skip the third login — the scan surfaces open ECB/OATH balances and flags the resolved-but-unpaid gap. See the deep-dive on liens and encumbrances.

How to check HPD violations on an occupied building

For any building with tenants, HPD violations (Class A/B/C) and Emergency Repair charges matter most — Class C hazards can trigger HPD repairs billed back as liens. Or skip HPD Online — the HPD complaint check pulls violations by class behind the LLC, in one scan.

Honest limit: this surfaces and flags every machine-readable public violation before you offer — it does not clear a lien, issue title insurance, or replace your title company’s certification. It moves discovery earlier; your attorney still closes it out.

Check 2: Liens & Encumbrances — ACRIS, DOF Tax Liens & ECB Judgment Liens

The pain: in NYC, a single property’s debts are not stored in one place. To find every encumbrance you have to query ACRIS (deeds, mortgages, lis pendens), DOF (tax liens, water/sewer arrears via DEP), OATH/ECB (judgment liens), and NY State eCourts/iCourts (docketed money judgments and mechanic’s liens that never touch ACRIS) — none of which cross-reference each other. As one guide puts it, “Liens are scattered across disconnected government portals… Missing even one lien can delay a closing by weeks”. Miss one and you inherit it: a single overlooked ECB judgment can carry five figures of liability the buyer cannot see until closing. Picture a two-family with $87,000 in outstanding ECB default judgments — the seller can’t pay it off and the title company won’t insure over it, so the deal dies at title.

NYC Property Intel runs all four lookups in one call. the lien & encumbrance check pulls DOF tax liens, ACRIS mortgages and lis pendens, and ECB/OATH judgment liens against the canonical BBL at once — surfacing your dollar exposure before you make an offer, not at attorney review.

How to find mortgages and lis pendens in ACRIS

Search ACRIS by BBL, list every recorded mortgage, then look for a matching Satisfaction of Mortgage (a missing one reads as an open lien even when the loan is dead). Check “Other Documents” for a lis pendens — a recorded notice of pending litigation that can extinguish a buyer’s rights if a foreclosing plaintiff wins. Or skip the logins: NYC Property Intel surfaces every recorded mortgage, satisfaction gap, and lis pendens on the BBL in seconds.

How to find DOF tax liens and ECB judgment liens

Pull the DOF tax-lien-sale list and current charges, then cross-check OATH/ECB: judgment liens “remain enforceable for Eight years… [and] must be satisfied at or prior to closing”. A DOB violation can read “resolved” while its ECB fine stays unpaid and silently ripens into a permanent DOF tax-lien assessment. Or skip the separate logins — one scan flags open ECB balances, docket dates, and tax-lien-sale inclusion.

Why this is not a title search (and what a title search still catches)

Be clear: this is due diligence, not a title search, and not title insurance. We aggregate machine-readable public data. We do not catch what isn’t in ACRIS — most docketed money judgments, mechanic’s liens, and building loan contracts are filed with the County Clerk and “are not recorded on ACRIS”, and Staten Island deeds aren’t in ACRIS at all. A formal title search and title insurance still verify chain of title, catch off-ACRIS filings, and indemnify you. Our job is to move the obvious, expensive surprises from closing to before your offer — so the title report confirms a clean property instead of killing your deal.

Check 3: Rent Stabilization & Overcharge Risk (the Pro Forma Killer)

You underwrote the building on its rent roll. The broker called four of the eight units “free market.” You modeled a 6% cap and a value-add bump. Then your attorney pulls the DHCR history at contract, and three of those “market” units turn out to be legally rent-stabilized — with rents 40% above the legal regulated rent. You haven’t just lost the upside. You’ve inherited the prior owner’s overcharge liability, and “reliance on the amount of rent charged by the prior landlord does not shield the new owner from damages… including treble damages”. HSTPA pushed the lookback to six years. This is the single line item that can flip a deal from “value-add” to “inherited lawsuit.” Stabilization status alone can reprice a building: after the 2019 HSTPA reforms, per-unit values for heavily rent-stabilized Manhattan buildings fell sharply as the value-add playbook lost its upside.

Signals a building is likely rent stabilized

NYC Property Intel’s rent-stabilization check surfaces the public signals that point to regulation, cross-referenced against the property lookup (BBL, year built, unit count, tax class) and abatement records:

A building can read “market” on the rent roll and still be stabilization-obligated because of an abatement nobody disclosed. We flag that mismatch before you write the offer.

What only a DHCR rent history can confirm

Here is the honest part, and it is the most important sentence in this check: there is no single authoritative public list confirming whether a NYC unit is rent stabilized. DHCR registration is owner-self-reported and unaudited; the RGB list is not determinative. NYC Property Intel flags likely stabilization and known abatement obligations from public data — it does not replace an official DHCR rent-history request, which is the only document that establishes the legal regulated rent and your true overcharge exposure.

That is the workflow: we move the red flag from “your attorney finds it at contract” to “you see it before you bid,” then you order the DHCR history with a specific reason to.

Underwriting an occupied building? Run the rent-stabilization scan first → — see the likely-stabilized units and abatement obligations before you model a single dollar of upside.

Check 4: Certificate of Occupancy, Illegal Units & Permits

You’re buying a Bushwick two-family listed as a “three-family with finished basement income.” The seller’s rent roll shows three checks every month. But the Certificate of Occupancy (C of O) on file at DOB says two legal dwelling units. That basement apartment is an illegal conversion — and the moment a DOB inspector confirms it, the city can issue a vacate order, displacing your paying tenant and zeroing out that unit’s rent overnight. According to NYC Dept. of Buildings, tenants in a unit without a valid C of O can legally withhold rent, and DOB can order the space vacated. You just capitalized a fictional NOI — and paid a third-family price for a two-family asset.

This is where the rent roll is probably fiction. Here’s how to catch it before you offer.

How to read a Certificate of Occupancy vs. the actual use

Run the property lookup to pull the property’s canonical BBL, zoning, and DOB records, including the legal C of O and permitted unit count. Then compare three numbers: (1) legal units on the C of O, (2) units the seller is marketing/collecting rent on, and (3) units on the DOF tax roll. When the marketed count exceeds the legal count, you’ve found a C-of-O mismatch — the cleanest public-data red flag there is. Note: pre-1938 buildings may have no C of O at all (they rely on an I-Card), which is its own financing and legalization hurdle.

Spotting an illegal apartment before you underwrite its rent

A C-of-O mismatch can trigger a DOB vacate order that zeroes out a unit’s income overnight — so never capitalize a unit the C of O doesn’t recognize. Cross-check the 311-complaint history and the DOB complaint check for “illegal conversion” or “illegal apartment” complaints. An unpermitted unit is a liability, not guaranteed income — confirm its legal status with your attorney and architect before you count its rent.

Checking permit history for unpermitted work

Run the permit-history check to see DOB BIS/NOW permit history. A finished basement or extra kitchen with no matching permit is a tell: the work was likely done off the books, meaning unresolved violations, possible ECB/OATH penalties, and a legalization timeline of months to years.

Honest limit: these tools flag the paper mismatch — they cannot see the hidden unit. Confirm legal use with a physical inspection and your architect before closing.

Want the C-of-O-vs-actual-use check on your target building? Run it in one query →

Check 5: The Local-Law Compliance Cost Bomb (LL11/FISP & LL97)

You can pass a mortgage stress test and still get ambushed 60 days after closing by a special-assessment check you never underwrote. As one NYC condo guide put it: “Nobody stress-tested whether you can write a $35,000 check on 60 days’ notice.” NYC mandates no minimum reserve fund, so the bill for the building’s deferred compliance lands on whoever owns the unit when the work comes due — and FISP, LL97, and LL152 can all fire at once. This check moves that discovery from “your board’s lawyer mentions it at the closing table” to “you see the exposure before you make an offer.”

Local Law 11 (FISP): facade inspection cost exposure

Every building 6+ stories must file a Facade Inspection & Safety Program (FISP) report every five years. An “Unsafe” rating forces a sidewalk shed (billed by the linear foot at roughly $40–$180/ft/month) plus repairs — and a single FISP compliance cycle can run $250,000 to over $1,000,000 on a larger building, typically billed as a lump-sum special assessment. The property lookup confirms the building qualifies (6+ stories via BBL/PLUTO), and the permit-history check plus the violation check surface active shed permits and open facade DOB/ECB violations that signal a cycle in progress.

Local Law 97: which buildings carry emissions-fine exposure

LL97 applies to buildings over 25,000 sq ft, which face annual carbon caps and a $268/ton penalty on overages that tightens sharply in 2030. We use the property lookup (square footage, tax class) to flag whether a target falls inside LL97’s coverage threshold at all — the single fact most pre-offer buyers skip.

What we flag vs. what an engineer must calculate

NYC Property Intel is a due-diligence flag, not a penalty calculator.

We point you to the exposure so you can price it in or order the engineering before you sign — not after.

Check 6: Tenant, Eviction & Housing-Court Litigation History

You underwrite the seller’s rent roll, not the war you inherit with it. In NYC housing court, a single non-paying tenant can run ~15 months to disposition plus ~6 more for the marshal’s warrant — and procedural traps make it worse: one Brooklyn dispute ran five years with $109,000+ in damages and fees (CBS News). A “discounted” occupied building stops being a discount the moment you net out the clearing cost. The problem: the data that would warn you is scattered across OCA, HPD, and 311.

How to check eviction history by address

The eviction-history check pulls the executed-eviction record (City Marshal evictions, 2017–present) for a BBL so you can spot recurring turnover before you offer — e.g., “unit 2R has multiple executed evictions, ask why.” Honest boundary: this surfaces executed evictions, not the full case history — filings, settlements, and dismissals live in the housing-court (OCA) docket. It cannot reveal a specific tenant’s current payment status, ERAP/hardship-stay posture, or shorten a court timeline — those stay with your attorney and the live OCA docket. For the full walkthrough, see NYC eviction history search by address.

Housing-court litigation history (the litigious-building signal)

The housing-court litigation check flags HPD housing-court actions against the ownership — the litigious-building signal that exposes entrenched, hard-to-clear tenancies. Appraiser Josane Cumandala puts the stakes plainly: rent-controlled tenants are “nearly impossible to evict… you basically have to wait for the tenant to die”. Cross-referenced with the rent-stabilization check status and ownership behind the LLC (the ownership lookup), prior litigation either corroborates or contradicts the seller’s narrative.

Reading 311 and HPD complaint patterns as distress signals

Complaints tend to precede violations: a sustained 311-complaint pattern often precedes escalated HPD inspections and Class B or Class C violations. The 311-complaint check plus the HPD complaint check turn a chronic-complaint pattern — heat/hot-water, no-access, illegal-occupancy — into a buy/no-buy distress signal, flagging likely AEP enrollment and future city-billed emergency repairs.

NYC Property Intel moves all three from “your attorney finds it at contract” to “you see it before you make an offer.”

Special Situations: 1031 Exchanges, Out-of-State Buyers & Auctions

These three buyer segments share one brutal feature: the cost of an undiscovered problem is enormous, and the time or distance to find it is squeezed to almost nothing. They are also where due-diligence speed is worth the most money.

Running due diligence inside the 1031 45-day clock

The 45-day identification window and the 180-day closing window run concurrently, and they are not extended for weekends, holidays, financing delays, or medical emergencies. As 1031 Specialists put it, “The IRS’s 45-day identification deadline often makes investors rush and skip due diligence, closing acquisitions as quickly as possible, which creates unnecessary risks.” Skip the wrong check on an NYC property and the bill is generational: a busted exchange triggers federal + NY State + NYC tax that, at top brackets, can reach the high-30s percent of the gain — easily six figures on a large gain. (Your CPA computes the actual rate; it varies with your income and the property. This is not tax advice.)

This is the tool’s single most defensible use case. The full due-diligence scan returns the slowest part of NYC due diligence — DOB/HPD/ECB violations, ACRIS liens, HPD litigation, eviction history, rent-stabilization signals — from one address query, so you can pre-screen ten candidates on Day 2 instead of discovering a dealbreaker on Day 44. It does not replace a title search, a DHCR rent-history request, or a physical inspection; it tells you which candidates are worth spending those remaining days on.

Remote due diligence for out-of-state and foreign buyers

Roughly 37% of Manhattan properties are held by secretive LLCs — 5x the state average — so even the seller’s identity can be opaque. Overseas buyers routinely close sight-unseen via Power of Attorney, where guidance reduces to “you need to fully trust your agent, inspector, and local contacts.” That trust is the exposure.

NYC Property Intel lets you verify what the agent tells you against the city’s own records:

It cannot verify a seller’s foreign-person status (FIRPTA), inspect finishes, or pull a confidential DHCR rent history — flag-and-refer, honestly stated.

Auction pre-bid: surviving senior liens and stabilized tenants

At foreclosure auction there is no escrow officer and no inspection. Buyers take title subject to surviving senior liens — “senior mortgages, property tax liens, and certain judgment liens survive the sale” — any one of which can erase the spread. And as serial co-op auction buyer Adam Plotch warns, “rent-stabilized tenants never die… it gives you eternal life.”

Before you bid, run the lien & encumbrance check to aggregate and date-order ACRIS mortgages, assignments, satisfactions, and lis pendens alongside DOF tax/water liens and ECB/HPD liens — approximating priority and flagging a surviving senior mortgage. Pair it with rent-stabilization and HPD-registration checks to spot a regulated, occupied unit before it becomes a multi-year trap. Final lien priority still needs an abstractor or attorney; this surfaces the senior-lien and regulated-tenant risks before the gavel, so you and your attorney can price them in or pass.

📋 On the 1031 clock? Screen candidates by Day 2.

Run the full due-diligence scan on every property you’re identifying — the slowest NYC checks (violations, liens, litigation, rent-stabilization signals) come back in one query, so you spend your remaining days only on candidates worth closing.

→ Scan a candidate free

The Complete NYC Pre-Offer Due Diligence Checklist (Run It as One Query)

Here’s the math that should scare every NYC investor: you screen 5–10 candidate properties for every deal you actually win. If due diligence means logging into DOB BIS and DOB NOW, ECB/OATH, HPD Online, ACRIS, DOF, 311, ZoLa, and DHCR for each one, you either spend a week per address or you cut corners — and the corner you cut is the $87,000 ECB judgment that kills the deal at title. Records are “spread across more than a dozen city agencies, each with its own database,” and “relying on only one of these systems could cause you to miss critical information” (NYC Dept. of Buildings). Due diligence has to be fast and repeatable or it doesn’t get done.

NYC Property Intel collapses 20+ sources into one query. Below is the master checklist — every line is a check the tool automates.

The 20+ Checks Mapped to What Each Catches

# Check What it catches Tool
1 Identity & zoning Wrong BBL, mis-zoned use the property lookup
2 DOB violations & complaints Open BIS/NOW violations the violation check / the DOB complaint check
3 HPD violations & litigation Class B/C, housing-court history, LLC principal the HPD complaint check / the housing-court litigation check / the ownership lookup
4 311 history Chronic-violator pattern, illegal-conversion tips the 311-complaint check
5 Liens & encumbrances DOF tax liens, ACRIS mortgages, lis pendens, ECB judgment liens the lien & encumbrance check
6 Rent-stabilization signals Likely-stabilized units, overcharge exposure the rent-stabilization check
7 Permits & FISP/LL11 Open facade work, expired boiler permits the permit-history check
8 Sales & deed history Fraud red flags, flip chains the sales-history lookup
9 Evictions Recurring executed evictions per unit the eviction-history check
10 FDNY incidents Standpipe/fire-safety history the fire-incident check
11 Block-level crime Corner-level NYPD trend the block-level crime check
12 Tax & assessment 421-a/J-51 cliff, RPIE reassessment the tax-assessment check
13 Comps Overpaying vs. arms-length sales the comps search
14 Neighborhood stats Trajectory context the neighborhood-stats search
15 Full risk roll-up Everything above, scored the full due-diligence scan

What it does NOT do: it surfaces and flags the public record. It does not replace a title search (mechanics liens and most docketed judgments aren’t in ACRIS), a formal DHCR rent-history request (per-unit legal rents are confidential), or a physical inspection. That honesty is the point — you see the risk before you make an offer instead of at closing.

NYC Property Intel vs. PropertyShark vs. Marketproof

NYC Property Intel PropertyShark Marketproof
Price Free — 3 queries/day no signup, 10/day with a free account; self-host unlimited (MIT) ~$59.95–$169.95/mo* ~$100+/mo*
Model AI natural-language query + MCP/agent access Static report pulls Report + list-building
Output Risk flags + plain-English answer Raw report Data dashboard
Data-vintage honesty Discloses indexing lag, ~33% dobjobs drift, confidential DHCR — flags-and-refers Not surfaced Not surfaced
Best for The occasional investor screening 5–10 deals List-builders Brokerages

Competitor pricing shown as of June 2026; check their sites for current rates.

The new aggregators (violationwatch.nyc, regwatch.nyc, dobguard.com) all claim “many sources in one place” — that’s table stakes now. NYC Property Intel differentiates on two things they don’t: natural-language AI query plus MCP/agent access, and radical data-vintage honesty (we tell you how stale each signal is and what to verify before you wire money).

What NYC Property Intel Does NOT Do (Read This)

We earn trust by being explicit about our limits:

This is due diligence, not certification. Verify before you wire money.

Next Steps

📄 The NYC Pre-Offer Due-Diligence Checklist

The full 20-point checklist above maps every one of the 20+ city data sources to exactly what it catches. Work it line by line, or run it as a single query.

🏙️ Screen your candidates — free

Enter one address and NYC Property Intel returns a normalized risk profile across all 20+ city data sources, in plain English, with honest data-vintage stamps. Three queries a day with no signup; sign up free for ten a day; self-host unlimited under the MIT license.

→ Scan an address free

FAQ: NYC Property Due Diligence

Do building violations transfer to the new owner in NYC?

Yes. In NYC, DOB and HPD violations, ECB/OATH judgments, and city-billed charges attach to the property, not the seller — so the buyer “steps into the shoes” of the prior owner at closing. Unpaid OATH/ECB judgments become liens enforceable for eight years and must be satisfied before you can close or refinance. A two-family carrying $87,000 in outstanding ECB default judgments, for example, can be impossible to close: the title company will not insure over them and the seller cannot pay them off. NYC Property Intel surfaces every open violation, summons balance, and docketed judgment before you bid — but we flag exposure, we don’t clear liens or issue title insurance.

No. A title search is a legal certification of clean ownership, performed by a title company and backed by title insurance. NYC Property Intel is a due-diligence screen: it aggregates 20+ public city data sources into one query so you see risk signals (ACRIS mortgages, lis pendens, ECB liens, DOF tax liens) before you make an offer. Critically, some encumbrances — mechanics liens, most docketed money judgments, and building loan contracts — are filed at the County Clerk and never appear in ACRIS at all. A “clean” ACRIS read is not a clean title. Always order a full title search before closing.

How do I know if a building is rent stabilized?

There is no authoritative, current, per-unit public source — DHCR registration is owner-self-reported and unaudited, and “the only way to know if your apartment is rent stabilized is to contact NYS HCR” (NYC Rent Guidelines Board). NYC Property Intel’s rent-stabilization check combines DHCR registration counts (2007–2017 data, which predate the 2019 HSTPA reforms), building age and unit count (PLUTO/DOF), and active 421-a/J-51 status to flag “this building almost certainly contains stabilized units” — a strong red flag that should trigger a formal DHCR rent-history request. It’s a screen, not a legal ruling, and it does not replace the official per-unit DHCR history (which matters because new owners inherit overcharge liability with treble damages and a 6-year lookback).

Can you check liens before I make an offer?

Yes — that’s the core move: shifting lien discovery from “your attorney finds it at contract” to “you see it before you offer.” The lien & encumbrance check unifies DOF tax liens, ACRIS mortgages and lis pendens, and ECB/OATH judgment liens into one BBL query. We also flag the common false-positive — an old mortgage with no recorded Satisfaction — which we label “unresolved on record, verify with lender,” never as outstanding debt. Two honest limits: we only read machine-readable public data, and new liens can attach in the contract-to-close gap, so a title continuation search is still required.

Do open DOB or ECB violations stop me from closing in NYC?

Often, yes. Title companies routinely refuse to insure over open ECB/OATH judgments, and many lenders won’t fund until they’re cleared — so unresolved violations can stall or kill a closing even when both parties want to proceed. Because ECB judgments stay enforceable for eight years — and under Local Law 153 of 2017 can be entered as a tax lien (automatically for a home of three or fewer units, or above $30,000–$60,000 thresholds for larger buildings) — they must typically be satisfied at or before closing. Finding them at the offer stage lets you make the seller cure them or reprice; finding them at closing usually means delay or collapse.

How long does NYC property due diligence take if I do it manually?

Done properly by hand, a single NYC building can take hours — you log into DOB BIS and DOB NOW, ECB/OATH, HPD Online, ACRIS, DOF, 311, ZoLa, and DHCR, then reconcile inconsistent BBLs and jargon across all of them. Multiply that by the 5–10 properties most investors screen per closed deal and manual due diligence becomes the bottleneck that forces corner-cutting. Running all 20+ sources as one query is what makes thorough pre-offer screening actually repeatable.

What does NYC Property Intel NOT replace?

Three things: (1) a title search and title insurance — we surface ACRIS/DOF/ECB signals but cannot certify ownership or insure it; (2) an official DHCR rent-history request — we flag likely stabilization but cannot rule on legal rent; and (3) a physical inspection — we show FISP/LL11 facade status, LL152 gas filings, C of O unit counts, and violation history, but we cannot see the boiler, the roof, or a hidden illegal unit. Public data also has known limits: indexing lag, the confidential DHCR registry, ~33% dobjobs drift, and occasionally mis-indexed BBLs. We disclose data vintage on every result — knowing what the public record can’t tell you is part of doing real due diligence.

Data sources & last updated: Reflects NYC Open Data and city systems (DOB BIS, DOB NOW, ACRIS, ECB/OATH, HPD Online, DHCR, ZoLa, DOF) through June 2026. NYC Property Intel surfaces and flags public records; it is not a title search, an appraisal, a DHCR legal-rent determination, or legal advice. Verify before you wire money.