What Is NYC Local Law 55?
NYC Local Law 55 of 2018 amended the New York City Administrative Code (§27-2056.11) to create enforceable mold assessment and remediation requirements for owners of multiple dwellings. Before this law, NYC landlords were required to address mold but had limited formal requirements for *how* — and remediation companies had no legal obligation to involve a licensed assessor.
Local Law 55 changed that.
The Core Requirements
1. Any mold remediation of more than 10 square feet requires a licensed assessor before work begins.
If you have a mold problem that covers more than 10 square feet of surface area — approximately a 2ft × 5ft patch — the following must happen before any remediation:
2. The assessor and the remediator must be different companies.
This is the key provision that most landlords and many contractors don't know. Under Local Law 55 and NYS Article 32, the mold assessor and the mold remediator for the same job cannot be the same individual or the same company. The purpose of this requirement is to prevent conflicts of interest: a company that both assesses and remediates has a financial incentive to overstate the problem.
If a contractor offers to assess and then immediately remediate, they are violating this requirement. You need two separate companies.
3. A post-remediation clearance inspection is required.
After remediation is complete, a licensed mold assessor must perform a post-remediation inspection to confirm that remediation was successful. The assessor issues a clearance certificate. This must be a different inspection from the pre-remediation assessment — it's an independent verification that the work was done correctly.
What Constitutes a "Multiple Dwelling"?
Local Law 55 applies to owners of multiple dwellings — buildings with three or more residential units. It does not formally apply to one-and-two family homeowners, though the practical advice of hiring a licensed assessor before remediation applies regardless of building type.
For multiple dwelling owners: this is a compliance obligation, not a best practice.
HPD Enforcement
NYC Housing Preservation and Development (HPD) enforces Local Law 55. Violations of the assessment requirement can result in:
Landlords who conduct remediation without a pre-remediation licensed assessment — or who use the same company for assessment and remediation — face additional violations beyond the underlying mold condition.
How to Comply with Local Law 55
The compliance sequence for a mold condition of more than 10 square feet:
1. Hire a NYS DOL Licensed Mold Assessor for a pre-remediation assessment. Get a written report.
2. Hire a NYS DOL Licensed Mold Remediator (separate from the assessor). Provide them the assessment report.
3. Remediation is conducted per the assessment report's scope.
4. Hire the licensed assessor (or a different licensed assessor) for post-remediation clearance inspection. Get clearance documentation.
5. Document everything. Maintain the assessment report, remediation contractor records, and clearance inspection for your records.
Common Mistakes Landlords Make
Using the same company for assessment and remediation. Many remediation companies offer "free assessments" as part of a package. These are usually illegal under Local Law 55 and NYS Article 32 — and their assessments cannot be used as the pre-remediation documentation required by law.
Treating remediation as a one-time event without addressing the moisture source. Mold returns if the moisture source isn't corrected. A proper assessment identifies the moisture source (roof leak, plumbing leak, condensation, groundwater intrusion). If the source is not corrected, remediation will need to be repeated.
Failing to document the clearance inspection. If HPD inspects after remediation, they will want documentation that remediation was successful. Without a clearance certificate from a licensed assessor, you cannot prove the condition was properly resolved.
What If a Tenant Reports Mold?
If a tenant reports a mold condition, NYC Admin Code requires investigation. Best practice:
1. Respond within 24 hours of the report
2. If the condition is more than 10 square feet, hire a licensed assessor before remediation
3. Document your investigation and remediation steps
4. Address the moisture source — not just the visible mold
5. Obtain post-remediation clearance
Failure to respond to tenant mold complaints is a basis for HPD complaints and rent reduction proceedings under NYC Rent Stabilization Law (for stabilized units).