Plain English:
505.6 other than Group R: If you're in a nonresidential occupancy (not Group R) but you're using "domestic-style" cooktops, ranges, or open-top broilers for domestic purposes, you still must provide a domestic cooking exhaust system. Translation: "domestic appliance" doesn't mean "no hood" just because the building isn't apartments/houses.
505.7 Group I-1 (assisted living, group homes, etc.)
Domestic cooking hood installs (per IBC 420.9) must meet ALL of the following:
Range hood minimum airflow: 500 cfm
Room ventilation per IMC 403.3.1
Hood exhaust must discharge outdoors
Exception: Ductless hood allowed only if it's listed/labeled AND has a charcoal filter to reduce smoke/odors.
505.8 Group I-2 (hospitals, nursing, etc.)
Same concept for domestic cooking installs (per IBC 407.2.7):
Range hood minimum airflow: 500 cfm
Room ventilation per IMC 403.3.1
Hood exhaust must discharge outdoors
Exception: Listed/labeled ductless hood allowed with charcoal filter.
On Plans: Why it matters
These sections are the "care occupancy reality check." In I-1 and I-2, the code forces a higher baseline (500 cfm plus room ventilation) because these occupants can't always self-evacuate and smoke control matters. If you miss the occupancy group early, you'll under-design the hood and get redlined.
Code Path: Where to show it
M-001: Note: "GROUP I-1/I-2 DOMESTIC COOKING HOODS: MIN 500 CFM, ROOM VENT PER 403.3.1, EXHAUST TO OUTDOORS; DUCTLESS ONLY IF LISTED WITH CHARCOAL FILTER (IMC 505.7/505.8)."
M-101: Tag the kitchen with the occupancy group (I-1 or I-2) and show hood exhaust routing to outdoors.
M-601: Hood tag/schedule: CFM, DISCHARGE (OUTDOORS / DUCTLESS LISTED), ROOM VENT METHOD PER 403.3.1, CODE REF (505.6/505.7/505.8).
Check: Do
Confirm occupancy group (R vs I-1 vs I-2 vs "other than R") before selecting the hood strategy.
Call out both pieces: hood exhaust AND room ventilation basis (403.3.1).
Review Risk: Don't
Don't assume "domestic appliance" means "ductless is fine" in I-1/I-2 without the listed/charcoal-filter condition.
Don't forget the minimum 500 cfm requirement in I-1 and I-2.
Field Tip:
When you see a "residential-style" range in a nonresidential project, drop a quick redline question: "WHAT OCCUPANCY GROUP SERVES THIS KITCHEN?" That one callout often prevents designing a standard R-hood where 505.7/505.8 actually applies.
Masterbuild QA Lens
Range hood listings are not universal. A hood listed for residential use over an electric range may not be listed for a gas range or for a range with a high BTU output. Confirm the hood listing specifically covers the appliance type, BTU rating, and installation configuration shown on the drawings. Coordinate the listing confirmation with the kitchen design before submittal.
Drawing / Submittal Check
For non-residential occupancies and I-1/I-2 buildings with domestic cooking exhaust (505.6-505.8): M-001 must identify the occupancy and confirm which subsection governs. Cooking exhaust in I-1 (assisted living) and I-2 (hospitals, nursing homes) has special requirements that differ from residential cooking. Confirm the exhaust rate, makeup air, and duct construction meet the specific subsection requirements.
Common Review Risk
For I-1 (assisted living) and I-2 (hospital) occupancies with domestic cooking exhaust: the most common error is applying residential cooking exhaust requirements to an institutional kitchen. Confirm the occupancy classification and the applicable subsection before designing the system. An institutional kitchen designed under residential cooking exhaust requirements will require a Type I or Type II commercial kitchen system - a significant scope increase.
When To Escalate
Escalate when the project is in a healthcare occupancy (I-1 or I-2) and the kitchen scope is ambiguous - some institutional kitchens in these occupancies need commercial cooking exhaust systems under IMC 506/507 rather than domestic cooking exhaust under 505. The classification affects the fire suppression requirement, the duct type, and the AHJ routing. Confirm the classification before the permit is filed.
Healthcare Ventilation Note
For healthcare work, verify the room use, pressure relationship, filtration basis, outdoor air/exhaust relationship, controls, and construction cleanliness expectations before the design is treated as permit-ready.
Kitchen Exhaust Coordination
For kitchen exhaust, tie the hood schedule, appliance lineup, grease duct route, cleanouts, fan discharge, fire suppression interface, and make-up air strategy into one reviewable story.