What a DOB Class 1 (Immediately Hazardous) violation means

A DOB Class 1 — also written as "Immediately Hazardous" — is the most serious tier of violations issued by the NYC Department of Buildings. These are the violations DOB treats as an immediate public-safety problem: illegal construction, serious structural defects, dangerous egress conditions, or ignoring a Stop Work Order. Penalties are high, the agency can halt the project, and in rare cases the building can be ordered vacated.

This guide explains what Class 1 typically covers, what happens procedurally, and the path to closing one out. Educational only — not legal advice or a filing manual.

What this means

DOB classifies violations by severity. Class 1 sits at the top. The Notice of Violation (NOV) issued by a DOB inspector usually travels with an OATH / ECB summons — meaning the case is scheduled for a hearing at the Office of Administrative Trials and Hearings (OATH). See our ECB / OATH basics guide for how those hearings work.

Class 1 categories you see repeatedly include:

• Work without a permit on structural, mechanical, plumbing, gas, or sprinkler systems.
• Failure to maintain the exterior wall when the violation is tied to a Local Law 11 / FISP reporting failure or an Unsafe condition.
• Construction site safety — inadequate sidewalk sheds, unsafe scaffolding, hoisting issues, or worker-safety infractions.
• Occupancy exceeds the Certificate of Occupancy (CO) — e.g., a three-family operated as a ten-family SRO.
• Ignoring a Stop Work Order. Doing work while an SWO is in place is separately penalized and the rates are steep.

DOB Class 1 can come with a Stop Work Order. An SWO means all work stops at the site until DOB lifts it — not just the work that caused the violation. Rescission requires a cure, a fee, and DOB inspector sign-off. Continuing work under an SWO is itself a separately penalized Class 1 offense.

Common causes

• Work without a permit on structural, mechanical, plumbing, or egress systems
• Failure to maintain the exterior wall (facade) when cited under a reporting rule
• Construction site conditions that endanger workers or the public
• Occupancy that exceeds the Certificate of Occupancy
• Ignoring a Stop Work Order (SWO) issued by DOB

Timeline

• Issued. The inspector issues the NOV / OATH summons at the site; the summons lists a hearing date roughly 6–8 weeks out.
• SWO (if applicable). Work must stop immediately. Rescission requires filing and inspection.
• Hearing. OATH hearing proceeds on the listed date; you or your representative appears (in person or virtually, per OATH rules).
• Penalty imposed. If DOB prevails, a civil penalty issues in the hearing decision.
• Certificate of Correction. Separate from the penalty, DOB expects a Certificate of Correction filing showing the condition is cured. See our cert-of-correction guide.

Penalties

DOB Class 1 penalties are laid out in NYC Admin Code § 28-202 and implementing DOB rules. Ranges vary sharply by offense type.

• Work without a permit: typically the higher of a flat penalty or a multiple of the permit fee that would have been due (often in the $6,000+ range for residential offenses, materially more for commercial, as a starting point — verify current schedule).
• Stop Work Order violation: per-day or per-occurrence penalties that can reach $25,000 or more for repeat offenders.
• Failure to maintain the exterior wall: penalty rises the longer the condition remains Unsafe, especially under Local Law 11 / FISP.
• Daily accrual. Some Class 1 conditions accrue per-day penalties if uncorrected.
• Certificate of Correction is separate. Paying the penalty does not close the violation — you must still cure the condition and file a Certificate of Correction.

How it typically gets resolved

1. Do not do-it-yourself. Class 1 almost always involves work that required a permit, a registered design professional (RDP), or a licensed trade. The cure path goes through those same professionals.
2. Stop work if an SWO is in place. Only DOB-authorized crews may access the site to perform the cure, and only under the cure scope.
3. Engage an expediter and RDP. The expediter navigates DOB NOW and the permit / rescission workflow; the RDP (architect or engineer) scopes the cure and signs any required filings.
4. Cure the condition. Depending on the violation, this might mean legalizing work, removing illegal construction, or correcting a facade Unsafe condition.
5. Appear at OATH — or settle. Mitigation evidence (the cure is underway or complete) typically reduces the penalty.
6. File a Certificate of Correction. The violation stays open on the record until DOB accepts the Cert of Correction, regardless of whether the penalty was paid.

When to hire a pro

Always.

• Registered design professional (RDP) — an architect or engineer — for any scoping, drawings, or corrective filings.
• NYC-licensed expediter to run the paperwork and communicate with DOB.
• Attorney for the OATH hearing, for penalty mitigation, and when the violation overlaps with litigation (e.g., construction-defect claims, tenant lawsuits).
• Licensed trades to perform the cure — plumbers, electricians, riggers, as applicable.

Related guides

• DOB Class 2 — major
• DOB Class 3 — lesser
• ECB / OATH hearings — the basics
• Local Law 11 — FISP facade inspection
• Certifying correction — HPD + DOB

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