When Are Fire Alarm Systems Required in Residential Buildings?

Ensuring life safety in residential buildings is a top priority in New York City, where the complexity of the built environment is matched by a stringent regulatory framework. Among the most critical safety systems are fire alarm systems, which are required in many residential projects. But when exactly are these systems mandated? What are the filing requirements? And how can owners and contractors stay compliant?

Fire Alarm System Requirements

Fire alarm systems in NYC residential buildings are typically required based on occupancy classification, building height, number of dwelling units, and means of egress considerations. The applicable codes include the NYC Building Code (BC) and Fire Code (FC).

Fire alarm systems can be broadly categorized into manual and automatic types, each serving distinct functions within a building’s life safety strategy:

• A manual fire alarm system requires human activation to initiate an alarm. This is typically done by pulling a manual pull station located near exits or in corridors.

• An automatic fire alarm system detects fire or smoke without human intervention, typically using smoke detectors, heat detectors, or other sensing devices.

When Fire Alarm Systems Are Required in Residential Buildings:

Under the NYC Building Code Section BC 907, fire alarm systems are required in the following residential situations:

Group R-1 (e.g. hotels, dorms, transient housing):

Manual Fire Alarm System – Not Required

A manual fire alarm system is not required only if all of the following conditions are met:

1. The building is no more than two stories tall.

2. Each sleeping unit and any connected attic or crawl space is separated from all other units and common areas by 1-hour fire-rated partitions.

3. Each sleeping unit has a direct exit to a public way, exit court, or yard (i.e., exterior exit access — no shared interior corridors).

Manual Fire Alarm System – Required

A manual fire alarm system is required if any of the following conditions apply:

1. The building is no more than two stories tall

2. Sleeping units or connected attic/crawl spaces are not fully separated from other units or common areas by 1-hour fire-rated partitions.

3. Any sleeping unit lacks a direct exit to a public way, exit court, or yard (i.e., units exit into interior corridors or common spaces instead of directly outside).

Automatic Smoke Detection System – Required for Public Corridors

If the building has public corridors and the sleeping units do not open directly to exterior exit access:

1. An automatic smoke detection system installed in all public corridors serving the units is required.

Smoke Detectors Within Dwelling and Sleeping Units – Required

Smoke detectors are required to be installed in the following locations and they are required to monitored by a constantly attended location:

1. Inside all sleeping areas

2. In every room along the egress path from the sleeping area to the exit door of the unit

3. On every level of the unit, including basements and below-grade stories

   1. For split-level units without a door between adjacent levels, a smoke detector on the upper level is sufficient for the lower level

4. A constantly attended location is defined as a designated location at a facility staffed by trained personnel on a continuous basis where alarm or supervisory signals are monitored and facilities are provided for notification of the Fire Department or other emergency services.

Special Cases:

• Student Dormitories:

  • Manual and automatic smoke detection is required in common areas, laundry rooms, mechanical and storage rooms, and interior corridors. Detection may be omitted if each unit has a direct exit to the outside and no interior corridors. Required smoke alarms must be interconnected with the fire alarm system.

• Large Group R-1 Occupancies:

  • Buildings with more than 50 sleeping rooms or large communal sleeping areas above street level must have automatic smoke detection, a fire alarm system, and an emergency voice/alarm communication system that supports full building evacuation.

Group R-2 (e.g. apartments, non-transient multifamily buildings):

• Required when:

  • Any dwelling unit is three or more stories above the lowest exit to a street.

  • Any dwelling unit is more than one story below the highest exit to a street.

  • The building has more than 16 dwelling units.

• Smoke detectors are to provided in the following locations:

  • Mechanical or electrical equipment rooms or similar rooms.

  • Air distribution systems

  • Elevator machine rooms

• Smoke detectors are required to be monitored by a central station or a constantly attended location.

Student Apartments (Group R-2)

• Buildings used primarily for R-2 student apartments must meet the same fire alarm requirements as hotels (R-1). In mixed-use buildings, the following apply:

  • Manual fire alarm systems are required in corridors and student common areas (lounges, dining, laundry), unless the building is under 2 stories with direct exterior exits or has fewer than 15 student apartments.

  • Automatic fire alarm systems (without in-unit notification) must signal a central or attended location. Detectors are required in corridors, equipment rooms, elevator areas, and HVAC systems—unless exempted as above.

  • In-unit smoke alarms are required per standard code.

Group R-3 (e.g. 1-2 family homes, small boarding houses):

• Typically not required to have fire alarm systems.

• May still require smoke alarms and carbon monoxide alarms, which are not part of a central fire alarm system but are still life safety devices.

Smoke & CO Alarms (Separate but Related):

Even when a central fire alarm system isn't required, smoke alarms and carbon monoxide alarms are required in almost all residential occupancies.

Filing and Regulatory Approvals for Residential Fire Alarm Systems

All fire alarm systems for residential buildings are subject to strict filing, permitting, and approval procedures through FDNY.

• FDNY Plan Review: fire alarm plans—including a TM‑1 form, sealed drawings, CO, or Letter of No Objection—to the FDNY Bureau of Fire Prevention.

• Project Authorization: Once FDNY approves, you'll receive a Project Authorization (formerly PAL), after which you may proceed with installation.

Inspections & Approval Letter: After installation and testing, FDNY conducts the final inspection. You’ll receive a Letter of Approval (LOA).

Understanding when fire alarm systems are required—and what type—is essential for code compliance and life safety in any residential project. If you need assistance determining the specific requirements for your building or are looking for expert fire alarm system design and filing support, our team at BUILT Engineers is here to help. We provide clear, code-compliant solutions tailored to your project’s needs.