Range hoods are required by building code in most places, but the rule depends on your stove type and where you live

Whether you must install a range hood is determined by your local building code, not by choice. Most jurisdictions require a hood over a gas stove, and many require one over an electric stove as well. However, the requirement varies by location — some cities mandate hoods for all cooking appliances, while others allow alternatives like downdraft ventilation or recirculating filters under specific conditions. Your city or county building department can tell you what applies to your address in one phone call.

If you are renovating an existing kitchen or installing a new stove, the code that applies is the one in effect when you pull a permit, not the code that was in place when the house was built. This matters because older homes sometimes have no hood at all, and you may be required to add one during a remodel even if the original kitchen never had one.

Key Takeaways

  • Gas stoves almost always require a ducted range hood by code; electric stoves have more flexibility depending on your location.
  • Your local building department determines what ventilation method is allowed — call them before you buy or install anything.
  • Recirculating hoods (which filter and return air to the kitchen) are permitted in some places but not others, and they do not meet code in most jurisdictions with strict ventilation rules.
  • If you are doing a kitchen remodel or replacing your stove, you will likely need to bring your ventilation system up to current code, even if the old kitchen had none.
  • Ducted hoods must vent to the outside; venting into an attic or crawlspace violates code and creates moisture and mold problems.

Gas stoves and building code requirements

Gas stoves produce moisture, carbon dioxide, and nitrogen dioxide during cooking. Building codes treat these as pollutants that must be removed from the home, which is why a ducted range hood is mandatory over a gas stove in virtually every jurisdiction. The hood must be vented to the outside — through a wall, roof, or soffit — not recirculated back into the kitchen.

The duct size and fan power required depend on your stove's BTU output and your local code. A typical residential gas stove requires a hood with at least 100 cubic feet per minute (CFM) of airflow, though larger stoves or commercial-style ranges may require 150 CFM or more. Your building department or the hood manufacturer can confirm the minimum for your specific stove.

Electric stoves and ventilation options

Electric stoves produce less moisture and fewer combustion byproducts than gas, so building codes are often more flexible about ventilation. Some jurisdictions allow a recirculating hood over an electric stove, while others still require ducted ventilation. A few places permit cooking without any hood at all over an electric stove, though this is uncommon in newer codes.

Before you assume a recirculating hood is acceptable, check with your building department. Even if it is permitted, a ducted hood removes heat and moisture more effectively and is the better choice for long-term kitchen comfort and durability. Recirculating hoods filter grease and odor but return warm, humid air to the kitchen, which can contribute to mold and wood damage over time.

Downdraft ventilation and other alternatives

Some kitchens use a downdraft system — a vent that pulls air down and away from the cooking surface, usually built into the countertop or the back of the stove itself. Downdraft systems are permitted by code in some places, particularly when a traditional overhead hood is not practical. However, they are less effective than overhead hoods because heat and steam rise naturally, and pulling them downward works against that physics.

If your kitchen layout makes a traditional hood difficult, talk to your building department about what alternatives they allow before you invest in a downdraft system. Some jurisdictions have specific rules about downdraft placement and duct sizing, and an undersized or poorly installed downdraft may not meet code even if the concept is permitted.

What happens if you do not have a hood when code requires one

If you sell your home or explore for a permit to remodel, a building inspector will check whether your ventilation meets current code. If it does not, you will be required to install one before the permit is signed off or before the sale closes, depending on your local rules. Some jurisdictions allow you to proceed with a variance — a formal exception to the code — but this requires a hearing and is not may provide.

Beyond code compliance, a missing hood creates practical problems. Cooking moisture accumulates in walls and attics, leading to mold, rot, and structural damage. Grease and odor linger in cabinets and drywall. Over time, the cost of repairing water damage far exceeds the cost of installing a hood upfront.

How to find out what your local code requires

Call your city or county building department and ask what ventilation is required over your stove type at your address. Have your stove's BTU output ready if you have a gas stove — the inspector may ask for it. If you are planning a kitchen remodel, ask whether you need to upgrade your existing hood or install one if you do not have one.

You can also check your local building code online; most municipalities post their codes on their websites. Search for "range hood" or "kitchen ventilation" in the residential code section. The language can be technical, but the building department can clarify what it means for your situation.

Ducting and installation rules that affect your options

Even if a hood is required, how you install it matters. The duct must be rigid or semi-rigid metal — flexible foil duct is not permitted by most codes because it traps grease and is a fire hazard. The duct must run as directly as possible to the outside, with no more than one or two bends. Long, convoluted ductwork reduces airflow and makes the hood less effective.

The duct cannot terminate in an attic, basement, or crawlspace. It must exit through an exterior wall or roof with a damper that closes when the fan is off, preventing cold air from flowing back into the kitchen. If your kitchen is on an upper floor and running a duct to the outside is difficult, talk to your contractor and building department about what routing is acceptable in your code.

Frequently Asked Questions

Can I use a recirculating hood instead of a ducted hood?

It depends on your local building code. Many jurisdictions permit recirculating hoods over electric stoves but not gas stoves. Call your building department to confirm what is allowed in your area. Even if permitted, a ducted hood is more effective at removing heat and moisture.

What if my kitchen does not have space for a range hood?

Talk to your building department about alternatives like a downdraft system or a hood installed at an angle. Some codes allow these in situations where a traditional overhead hood is not feasible. You may also be able to request a variance, though approval is not may provide.

Do I need a new hood if I replace my stove?

Not necessarily. If your existing hood is ducted, properly sized, and in good condition, you can usually keep it. However, if you are upgrading from an electric to a gas stove, you may need a more powerful hood. Check with your building department if you are unsure.

What size hood do I need for my stove?

For gas stoves, the hood must handle the stove's BTU output — typically 100 to 150 CFM for a residential stove. For electric stoves, requirements vary by location but are often less stringent. Check your stove's specifications and your local code, or ask the hood manufacturer for a recommendation.

Can I vent my range hood into the attic?

No. Building code requires the duct to terminate outside the home. Venting into an attic traps moisture, which causes mold, rot, and structural damage. The duct must exit through an exterior wall or roof with a damper.