347-392-6356Contact Us
N
Nacmias Law Firm, PLLC

NYC Building Code

§ 909.20.4.2.1 — § 909.20.4.2.1

Talk to an AttorneyView on AmLegalCall 347-392-6356

Brooklyn since 2014All five boroughsSame-day response during business hours

What is NYC BC § 909.20.4.2.1?

Quick Answer

This section outlines the requirements for engineered ventilation systems in buildings, specifying that such systems must exhaust at least 90 air changes per hour from any vestibule during emergency operations. It mandates the installation of smoke detectors at the floor-side entrance of each vestibule, activating the system as needed. Applies to building owners utilizing engineered ventilation systems.

General informational summary. Not legal advice for your situation. Consult an attorney before acting on any specific matter.

Michael Nacmias - Founding PartnerMichael Sargo - Partner
From the team atNacmias Law Firm, PLLCBrooklyn-based attorneys representingproperty owners across all five boroughsMeet the team →

909.20.4.2.1 Engineered ventilation system.

BC § 909.20.4.2.1

Where a specially engineered system is used, the system shall exhaust a quantity of air equal to not less than 90 air changes per hour from any vestibule in the emergency operation mode and shall be sized to handle three vestibules simultaneously. Smoke detectors shall be located at the floor-side entrance to each vestibule and shall activate the system for the affected vestibule. Smoke detectors shall be installed in accordance with Section 907.3.

Common Questions

Our team

Meet the people you will work with

View all team members

Resources & updates

Practical resources for NYC legal problems.

Browse practical legal articles, violation-code tools, city-agency resources, and searchable references without leaving the landing page.

DOB Violations

NYC DOB Certificate of Correction: New DOB NOW Safety Portal Launches December 2025

The new DOB NOW: Safety portal is live as of December 15, 2025. Learn the 5 key changes, step-by-step submission process, and how to avoid the 20 common disapproval reasons.

8 min readOpen
Building Code Violations

What Are the Critical NYC DOB Updates for December 2025?

NYC property owners face urgent DOB deadlines: a historic basement legalization program, year-end inspection reports due December 31st, and the new 2025 Electrical Code effective December 21st. Here's what you need to know.

8 min readOpen
DOB Violations

Understanding DOB Violations: A Complete Guide

Your complete guide to understanding, navigating, and resolving NYC Department of Buildings violations with confidence. Learn about violation classes, penalties, and resolution strategies.

15 min readOpen
Traffic Violations

NYC Failure-to-Yield (§ 19-190[b]) at OATH: What to Expect

Complete guide to NYC Admin Code § 19-190(b) 'Failure to Yield Causing Physical Injury' summonses at OATH. Learn about phone hearings, flat fee structure, and what to expect from the process.

8 min readOpen
1 / 2

Need something specific? Search the full resources library for articles, agencies, violation codes, and legal-code references.

Search all resources

Free case review

Have a matter that touches § 909.20.4.2.1?

Free 15-minute case review with the attorney handling your matter. Same-day response during business hours across all five boroughs — OATH hearings, Housing Court, and real estate closings.

Schedule ConsultationCall 347-392-6356

Or email us

[email protected]

An attorney reads every message.

  • Same-day response

    During business hours

  • Direct attorney access

    Same lawyer from intake to close

  • Flat-fee pricing

    On most OATH and closing matters