You're redoing the kitchen in your Broad Ripple bungalow, the old hood is out at the curb, and you stop to ask: is a range hood required by code in Indiana? No. Indiana's home code doesn't make you put a hood over a home range. A Marion County kitchen with no window or skylight still needs a fan that vents outside.
Put one in, and the code has rules for it. Your range needs clear space too.
Start with your kitchen:
- You want no hood at all: the state home code doesn't require one. Check your range's install guide, because the code says to follow it.
- You're putting in a hood with a duct: the duct has to carry the air outdoors. It can't end in the attic, the crawl space or anywhere inside.
- You're putting in a ductless hood: it's allowed if it's listed and labeled, put in the way its maker says, and the kitchen has other ventilation.
- Your hood moves more than 400 cubic feet of air a minute: the house may need makeup air. It depends on what else burns fuel in the house.
- You have a microwave over the range: the cabinet above it has to sit high enough. GE asks for 30 inches or more above the cooking surface.
- You live in Marion County and the kitchen has no window or skylight: section 10-502 of the county housing code wants a fan system that vents outside. It doesn't have to be a hood.
Does code require a range hood?
No. The code's kitchen exhaust rules only apply where someone chooses to put that gear in. You can see it in how section M1503.2 of the 2020 Indiana Residential Code starts. Its first word is "Where".
The rules kick in once a hood exists, and they don't order you to buy one.
Read the exact wording
"M1503.2 Domestic Cooking Exhaust Where domestic cooking exhaust equipment is provided, it shall comply with one of the following:"
Who makes the rule here?
The state does. Indiana's home code governs new work and alterations, which covers building a house or changing one. And the state says local offices like Indianapolis's still run the permits and the inspections.
The Indiana Department of Homeland Security says the building rules enforced across Indiana are the state commission's rules, with no local changes. That's the state's view, and the state says its view isn't binding. So a tougher city rule for hoods is unlikely, but not ruled out. The state's 2019 final rule didn't change the hood sections of the model code either. Marion County's housing code is a separate rule. It asks for kitchen ventilation, not a hood.
Read the exact wording
"In effect, this legislation has created a framework where the substantive building and fire safety laws that are enforced throughout Indiana are the unamended rules of the Commission."
From Indiana Department of Homeland Security, Boards and Commissions
New homes and whole-house fans
Some new homes need whole-house ventilation, a fan system that brings in fresh air. That's a different rule from a range hood rule. Section R303.4 asks for it when a test shows the house is very airtight, and Indiana's version of N1103.6 asks every new home for ventilation that meets section M1505 "or other approved means." Section M1505.4.1 lets a builder use exhaust fans, like a kitchen fan, as that system. In a newer home, ask the builder before you take a kitchen fan out.
Is it legal to not have a range hood?
Yes, under the state home code. No section of it tells you to have one over a normal range. The one case is an indoor open-top broiler, which needs a metal hood unless it's listed for use without one, under section M1503.2.1. Three things can still change the answer for your kitchen. One is the range maker's install guide. One is the rules that apply once a hood goes in. The third, in Marion County, is the housing code's rule for a kitchen with no window or skylight.
Your range maker gets a say
The code says a cooking appliance has to be installed the way its maker says. That's in section G2447.1 for gas and section M1901.2 for all ranges. If your range's guide calls for a hood, the guide wins.
Read the exact wording
"M1901.2 Cooking Appliances Cooking appliances shall be listed and labeled for household use and shall be installed in accordance with the manufacturer's instructions."
What does the code ask if you put a hood in?
It asks for a duct that carries the air outdoors, or a listed ductless hood. The biggest hoods need makeup air too. Each one has its own section.
If you put in a hood with a duct
The air has to go outdoors through a duct, under section M1503.3. The code asks five things of that duct:
- Smooth inside: the code asks for a smooth inner surface.
- Airtight: no leaks along the way.
- A backdraft damper: a flap that keeps outside air from blowing back in.
- Its own path: it can't share with any other exhaust system.
- The right metal: galvanized steel, stainless steel or copper, under section M1503.4. A downdraft vent under a concrete floor can use PVC pipe.
And it can't end in the attic, in the crawl space or anywhere inside the building.
Read the exact wording
"M1503.3 Exhaust Discharge Domestic cooking exhaust equipment shall discharge to the outdoors through a duct. The duct shall have a smooth interior surface, shall be air tight, shall be equipped with a backdraft damper and shall be independent of all other exhaust systems. Ducts serving domestic cooking exhaust equipment shall not terminate in an attic or crawl space or areas inside the building. Exception: Where installed in accordance with the manufacturer's instructions, and where mechanical or natural ventilation is otherwise provided, listed and labeled ductless range hoods shall not be required to discharge to the outdoors."
If you put in a ductless hood
A ductless hood sends the air back into the kitchen, not outside. The same section allows it as an exception. There are strings, though. The hood has to be listed and labeled, it has to go in the way its maker says, and the kitchen needs some other mechanical or natural ventilation.
If your hood is a big one
A hood that can move more than 400 cubic feet of air a minute may need makeup air, which is air brought in to replace what the hood blows out. Section M1503.6 asks for it only in some houses. The house has to hold a fuel-burning appliance that isn't direct-vent and doesn't use a fan to push its exhaust out.
If you don't know what kind of furnace or water heater you have, ask a heating contractor before the hood goes in.
Read the exact wording
"M1503.6 Makeup Air Required Where one or more gas, liquid or solid fuel-burning appliance that is neither direct-vent nor uses a mechanical draft venting system is located within a dwelling unit's air barrier, each exhaust system capable of exhausting in excess of 400 cubic feet per minute (0.19 m 3 /s) shall be mechanically or passively provided with makeup air at a rate approximately equal to the exhaust air rate."
Is it okay to not have a range hood?
By the state code, yes. It leaves the choice to you and to your range maker's install guide. In Marion County, a kitchen with no window or skylight still needs a fan that vents outside. That fan doesn't have to be a range hood.
Where a kitchen exhaust fan is put in, the code has a table for it, in section M1505 of the Indiana code. It lists 100 cubic feet of air a minute for a kitchen fan that runs now and then, or 25 for one that runs all the time.
Read the exact wording
"M1505.1 General Where local exhaust or whole-house mechanical ventilation is provided, the equipment shall be designed in accordance with this section." and, from Table M1505.4.4, "Kitchens 100 cfm intermittent or 25 cfm continuous"
Three things to look at tonight
- Read your range's install guide: look for the words "hood" and "clearance".
- Find your hood's model number: then look up its air flow in cfm, short for cubic feet a minute.
- See where the duct ends: it should end outdoors. If it runs through the attic, look from the hatch, and only if you can do it safely.
A hood is no fix for a gas smell. If you smell gas at the stove, follow the steps in what to do if you smell gas near your stove. And a gas oven is never a heater, as our guide on heating a house with a gas oven explains.
How much space does the code want above a range?
Thirty inches. That's the rule in section M1901.1 of the Indiana code. A range needs at least 30 inches from the cooking top up to anything above it that can burn and isn't protected. Think of a wood cabinet.
The space can be smaller in one case. A hood or an over-the-range microwave comes with a listing and a label, and the code allows the smaller space those call for.
Read the exact wording
"M1901.1 Clearances Freestanding or built-in ranges shall have a vertical clearance above the cooking top of not less than 30 inches (762 mm) to unprotected combustible material. Reduced clearances are permitted in accordance with the listing and labeling of the range hoods or ovens with integral exhaust."
Above a gas range
The fuel gas chapter adds metal cabinets to the list. Section G2447.5 asks for 30 inches from a gas cooking top to anything that can burn and to metal cabinets. It allows 24 inches in three cases:
- A covered cabinet bottom: the underside has 1/4-inch insulating millboard covered with thin sheet metal.
- A metal hood: a sheet metal hood at least as wide as the range, centered over it, with at least 1/4 inch of space between the hood and the cabinet.
- A listed microwave or cooker above: a listed microwave or other listed cooking appliance, put in the way its maker says.
Read the exact wording
"G2447.5 (623.7) Vertical Clearance Above Cooking Top Household cooking appliances shall have a vertical clearance above the cooking top of not less than 30 inches (760 mm) to combustible material and metal cabinets. A minimum clearance of 24 inches (610 mm) is permitted where one of the following is installed: 1. The underside of the combustible material or metal cabinet above the cooking top is protected with not less than 1/4-inch (6.4 mm) insulating millboard covered with sheet metal not less than 0.0122 inch (0.3 mm) thick. 2. A metal ventilating hood constructed of sheet metal not less than 0.0122 inch (0.3 mm) thick is installed above the cooking top with a clearance of not less than 1/4 inch (6.4 mm) between the hood and the underside of the combustible material or metal cabinet. The hood shall have a width not less than the width of the appliance and shall be centered over the appliance. 3. A listed cooking appliance or microwave oven is installed over a listed cooking appliance and in compliance with the terms of the manufacturer's installation instructions for the upper appliance."
A microwave over the range
We've read one maker's guide, GE's, so take these as GE's numbers and not every brand's. GE's install guide for its JVM3160RFSS microwave wants the bottom of the cabinet above it 30 inches or more from the cooking surface. It wants the top of the microwave 66 inches or more from the floor.
GE also says that model can sit over an electric or gas range with a combined 63,000 BTU or less. Your range's own guide may ask for more room. Read both.
Read the exact wording
"Bottom edge of cabinet needs to be 30″ or more from the cooking surface" and "66″ or more from the floor to the top of the oven"
From GE Installation Instructions, Over-the-Range Microwave Oven, model JVM3160RFSS
Notes to have ready for the call
If the range is acting up, these help the tech:
- The range: gas or electric, and the make and model.
- What's wrong: what it does, and when it started.
- The hood, if you have one: whether it vents outside or blows back into the kitchen.