Whole-house mechanical ventilation required when designed to NY ECCC §R402.5.1 air-tightness; local exhausts per M1505.5
2025 RCNYS §M1505 Mechanical ventilation (whole-house + local)Description
Where local exhaust or whole-house mechanical ventilation is provided (or required to satisfy R325 alternatives), the system must comply with M1505. Exhaust air from bathrooms / toilet rooms / kitchens shall NOT be recirculated; it must discharge directly to the outdoors. Whole-house ventilation systems must be designed per M1505.4 (typical: 0.35 ACH or 7.5 cfm/person + 1 cfm/100 sqft). Local exhausts must meet Table M1505.5 — bathroom 50 cfm intermittent OR 20 cfm continuous, kitchen 100 cfm intermittent (vented hood) OR per appliance rating.
Why this exists
Modern tight envelopes (R402.5.1) make passive ventilation insufficient. Architects designing to ECCC NY must include a whole-house ventilation strategy — typically a balanced ERV in cold climates. The bath/kitchen exhausts are then sized + ducted as a coordinated system, not afterthought fans.
Measurements
| Property | Operator | Value | Unit | Note |
|---|---|---|---|---|
bathIntermittent | min | 50 | cfm | Bathroom intermittent exhaust rate |
bathContinuous | min | 20 | cfm | Bathroom continuous exhaust rate |
kitchenIntermittent | min | 100 | cfm | Kitchen intermittent exhaust rate (vented hood) |
Categories
Applies to
- Jurisdiction: New York State
Source
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Natural light in habitable rooms · IRC R303.1
- Carbon monoxide alarms in sleeping areas · IRC R315
- Garage HVAC duct prohibition · IRC R302.5.2
- Natural ventilation in habitable rooms · IRC R303.1 (vent)
- Bathroom ventilation · IRC R303.3
Last reviewed 2026-05-15.