How to File a 311 Mold Complaint in NYC — Step by Step for Inwood Tenants

Most tenants in Inwood know they can call 311. What most do not know is exactly what happens after – what the HPD inspector actually looks for (Article 32 and Local Law 55 govern what they must act on), what a violation means in practice, how long the landlord legally has to fix it, and what your options are when they do not. That uncertainty is part of why landlords get away with slow-walking mold repairs for months.

And the system does get used here. Inwood residents filed 401 mold complaints with 311 in 2025, about 3 times the Manhattan rate per apartment, and HPD issued 396 mold violations in the neighborhood that year. See the full numbers in our Inwood mold data report.

This is the full process, step by step, specific to how it plays out in Manhattan and in the pre-war rental buildings that make up most of Inwood’s housing stock.

How do I file a 311 mold complaint in NYC?

Filing is straightforward. You have two options: call 311, or go to nyc.gov/311 online. Online is usually faster and gives you a written record of what you submitted. When you file, select a housing complaint and choose mold or moisture as the issue type. Provide your full address including the apartment number – floor and unit, not just the building address.

You will receive a complaint number. Save it. Write it down. Take a screenshot. This number is how you track your complaint status, and it is the reference number you will need if you follow up with HPD or escalate to Housing Court.

After you file, check your status at hpdonline.hpdnyc.org. Search your building address and you can see all open complaints, scheduled inspections, violations issued, and their resolution status. This is public information – your landlord can see it too, which is part of why a formal 311 complaint moves things in a way that a phone call to the super never does.

What does HPD actually do when they inspect for mold?

An HPD code inspector comes to your apartment – you need to be present to let them in. They do a visual inspection of the affected areas. If they find visible mold, they classify it and issue a violation against the property owner. If they do not see visible mold, no violation is issued, even if you smell it or believe it is hidden behind a wall.

This is the part most tenants do not fully understand: HPD inspectors issue violations for visible mold only – they do not test for mold type, they do not measure air quality, and they do not open walls to look for hidden growth. That distinction matters enormously in Inwood’s older buildings, where mold frequently lives inside wall cavities fed by slow pipe leaks that may not show on the surface for months. An HPD violation is a powerful legal tool, but it only captures what the inspector can physically see on the day they visit.

If you want documentation of hidden mold – the kind that carries weight in Housing Court and establishes actual extent and source – that requires an independent licensed mold assessor with air and surface sampling sent to an accredited lab. That is a separate service from the HPD inspection, and it is what Article 32 requires before any licensed remediation can begin anyway.

How long does HPD take to inspect after a 311 mold complaint?

For a standard mold complaint, HPD typically schedules an inspection within 5 to 15 business days. That window can be shortened if you specifically describe vulnerable household members – children under six, elderly residents, or anyone with a diagnosed respiratory condition like asthma. Mention these details when you file the complaint, not as an afterthought.

For what HPD classifies as an emergency condition – active water intrusion, sewage backup, mold that appears to be immediately hazardous – the inspection can happen within 24 hours. If your situation is genuinely urgent, say so clearly when you file and call 311 directly rather than using the online form, since phone complaints can be flagged for faster response.

What do HPD violation classes mean – Class B vs Class C?

When an HPD inspector finds visible mold and issues a violation, they classify it by severity. Class B is hazardous with a 30-day cure window; Class C is immediately hazardous (30+ sq ft of mold in a room) with a 21-day window. Fines reach $10,000. Both require a landlord Certification of Correction.

Class B – Hazardous. This is the most common mold violation. The landlord has approximately 30 days to correct it and file a Certification of Correction with HPD. Fines for non-correction accumulate over time and can reach significant amounts. A Class B violation stays on the property record and affects the landlord’s ability to do certain business with city agencies.

Class C – Immediately Hazardous. A more severe classification, issued when there are 30 or more square feet of mold in a room. Class C violations must be corrected within 21 days. Fines for non-correction are higher and escalate faster.

Either violation gives you a strong legal foundation for an HP Action in Housing Court if the landlord does not comply within the cure window. The open violation is the first thing a Housing Court judge will look at when you explain why you are there.

What happens after HPD issues a mold violation?

After HPD issues a mold violation, the landlord receives written notice with the classification and required correction date. They must fix the mold within the cure window and file a Certification of Correction with HPD. Failure to comply results in escalating fines and potential Housing Court action.

1. Correct the condition – which for mold means actual remediation, not painting over it. For any mold area over 10 square feet in a building with 10 or more units, Article 32 requires a licensed mold assessor and a licensed remediation contractor. A handyman with Kilz does not satisfy this.

2. File a Certification of Correction with HPD after the work is done. This is a formal document stating the condition has been corrected. For larger mold jobs, it should be accompanied by independent clearance testing – an assessor who was not the remediator confirming the job is actually clean. Without that independent clearance, the landlord is essentially self-certifying, which is exactly what Article 32 was written to prevent.

You can track whether a Certification of Correction has been filed at hpdonline.hpdnyc.org. If the violation remains open past the cure window and no certification has been filed, the landlord is accumulating daily fines and you have clear grounds for an HP Action.

What if the HPD inspector does not find any mold?

This happens, especially in Inwood’s older buildings where the mold source is behind drywall or inside a pipe chase that is not visible from the apartment. If the inspector came and found nothing, but you still smell mold or see it return within a few weeks, you have two options.

First, you can re-file 311. There is no limit on how many complaints you can file, and a pattern of complaints on a single property is itself useful information in Housing Court. File again when the visible mold returns.

Second – and more effectively – you can hire an independent licensed mold assessor to do a full assessment with air and surface sampling. That report documents what the HPD inspector cannot: the airborne spore count, the surface contamination behind a wall or under flooring, the moisture readings that point to a hidden source. It is the kind of evidence that turns an inconclusive HPD inspection into a clear legal case. It is also what the law requires before remediation of any mold project over 10 square feet anyway – so if your landlord is eventually forced to fix it properly, this assessment is the first step in that process.

We remediate. Assessment and clearance are done by an independent licensed mold assessor we coordinate for you, so the company that diagnoses the problem never profits from the fix. That separation is both the law and the point. Call us at (917) 694-9003 to talk through your situation.

Does 311 work for NYCHA tenants at Dyckman Houses?

Partially, but with a critical difference. HPD does not inspect NYCHA-owned buildings the same way it inspects private buildings. If you are a tenant at Dyckman Houses or another NYCHA development in Inwood, filing 311 may trigger a response but it does not carry the same force as it does in a private rental.

NYCHA has its own internal maintenance request system, and complaints there often go into a queue that moves very slowly.

For NYCHA tenants, the HP Action in Housing Court is generally the more effective route – it applies to NYCHA the same way it applies to any landlord, and courts have ordered NYCHA to make repairs in individual apartments. See our NYCHA mold guide for Dyckman Houses residents for the specific pathway and what to realistically expect.

Should I do anything before calling 311?

Two things, in order. First, document the mold thoroughly – dated photos and video of every affected area, a written note of the smell and any symptoms, and the date you first noticed it. Second, notify your landlord in writing. Send an email describing the mold and requesting repair within 14 days. Keep the email.

The written landlord notice is not legally required before you call 311, but it strengthens your position significantly. It establishes that the landlord had direct knowledge of the condition and chose not to act – which is relevant both to HPD’s violation assessment and to any subsequent Housing Court proceeding. A paper trail that starts with tenant notice, followed by landlord inaction, followed by 311, followed by HPD violation is a much stronger record than 311 cold with no prior notice.

For the full step-by-step process including what to do before and after 311, see our complete guide: What to do when your landlord won’t fix mold in NYC.