Is a kitchen expansion an addition or an alteration?

An addition if it increases both conditioned floor area and conditioned volume, as a bump-out does. Expanding into existing conditioned space adds neither and is an alteration.

Does a larger kitchen need a bigger range hood?

Not by kitchen size. Table 150.0-G sets the hood by dwelling unit floor area and whether the range is gas or electric.

Kitchen Expansion Title 24 Requirements

A kitchen expansion is an addition only if it adds both floor area and volume, such as a bump-out or an enclosed porch; opening a wall into a room that is already conditioned is an alteration. Either way the range hood, recessed lights and dimmers answer to the Energy Code, and no electric cooktop-ready wiring is required.

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Which side of the line your expansion falls

A bump-out, an enclosed porch or garage bay, or a floor-to-ceiling bay window increases area and volume, so it is an addition under Section 150.2(a). Taking in a dining room that is already conditioned adds neither and is an alteration, covered on the kitchen remodel page. A project that does both is documented as an addition with alterations.

The hood depends on house size and fuel

Table 150.0-G sets a vented hood by dwelling unit floor area and range fuel. Over 1,500 square feet an electric range needs 50 percent capture efficiency or 110 cfm and a gas range 70 percent or 180 cfm; over 1,000 up to 1,500 square feet gas rises to 80 percent or 250 cfm. Because the rows follow floor area, give the report the finished area. Removing the wall to the living room matters too: a nonenclosed kitchen must use demand-controlled exhaust, while an enclosed one may choose demand-controlled or continuous. Recirculating hoods are not accepted, and an ECC-Rater confirms the hood's rated airflow or capture efficiency and sound. Product choices are on range hoods.

Lights and controls

Recessed cans take no screw-base sockets, carry an airtight label of under 2.0 cfm at 75 pascals and are sealed to the ceiling.
Kitchens need readily accessible dimming controls; range hood lights are exempt, and drawer or cabinet light of 45 lumens per watt or more is exempt from the efficacy rule.
Under-cabinet lighting and switched outlets are controlled separately from the ceiling lights.

Wiring and walls

Section 150.2 does not carry the cooktop-ready rule of Section 150.0(u) to additions or alterations. Walls that simply extend existing framing need R-15 cavity insulation in 2x4 or R-21 in 2x6, and windows over the sink count against the glazing cap for the size tier, explained on the room addition page. Light fixtures are covered under replacing light fixtures.

A kitchen opened onto a family room is covered on the family room addition page. Reports start at our residential service.

Common Title 24 Questions

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