What Is a Built-In Dishwasher?

Inside the tub, rotating spray arms throw hot water and detergent at the dishes, a filter traps food particles, and sensors read how dirty the water is and adjust the cycle. A heated dry phase finishes the load. The wash system is the same idea across the category; what sets a built-in apart is how it connects to the house.

Three connections define it. A hot-water supply line feeds the machine, a drain hose carries the dirty water to the sink drain, the disposer or a dedicated drain, and a power connection runs to a dedicated circuit. Nothing hooks to the faucet, and nothing rolls away afterward.

Because the cabinets enclose the machine and an insulation blanket wraps the tub, a built-in runs quieter than a portable. The cabinet box absorbs sound on the sides and top, and the blanket muffles what is left.

The four home types differ mainly in where they sit and how they connect, and that difference decides who each one suits.

A built-in cannot be used as a freestanding unit. It has no finished sides or top and is built to be enclosed by cabinetry, so setting one in the open leaves bare panels showing and nothing supporting the countertop edge above it.

Retail listings use several labels for the same under-counter form factor, and each one describes a small variation rather than a different appliance.

• Built-in or undercounter: US retailers use the two words interchangeably for the same thing.
• Semi-integrated (front control): the controls sit visible on the front of the door.
• Fully integrated (top control): the controls hide on the top edge of the door, so the front reads as a plain panel.
• Panel-ready: the door is built to accept a custom cabinet panel so the dishwasher matches the kitchen; the panel adds about 3/4 inch to the depth.
• Drawer dishwasher: a single or double drawer instead of a full-height door.
• ADA-height or short built-in: a lower machine for lowered counters, raised floors and aging-in-place layouts.

"Built-under" is a term used mostly outside the US for a unit that fits under a counter but keeps a visible front. In the US, that machine is simply sold as a built-in.

The machine measures about 23-7/8 inches wide so it slides into a 24-inch opening, roughly 24 inches deep, and 33-1/2 to 35 inches high with the leveling legs. The slim version is 18 inches wide. Oversized units of 30 to 42 inches exist but are rare in homes.

The rough opening is the number that matters: about 24 inches wide, 24 inches deep and 34-1/2 inches high from the floor to the underside of the countertop. Leave at least 2 inches of clearance in a corner installation, and plan on a countertop at least 25 inches deep if you want the door to sit flush.

How to measure the opening

Measure the width at the top and the bottom of the opening, the height at the left, middle and right, and the depth from the front of the cabinet to the back wall. Cabinets and floors are rarely level, so the smallest height you find is the one that counts. The leveling legs take up the slack.

Capacity by size

A 24-inch built-in holds roughly 12 place settings, with listings ranging from 10 to 16. An 18-inch slim model holds about 8. The opening, not the machine, decides what fits, so measure before you shop.

A built-in needs a hot-water supply, a drain path and a dedicated circuit, and each has its own requirements.

Water and drain

The supply is a 3/8-inch line off the hot-water pipe, at 20 to 120 PSI, with the water heater set between 120 and 140°F. The drain hose runs no longer than 10 feet and needs an air gap or a drain loop raised about 32 inches; an air gap is required where the drain connection sits low.

Electrical

The machine runs on 120V, 60Hz, on a 15- or 20-amp grounded dedicated circuit. In the US, the National Electrical Code permits a built-in dishwasher to be cord-and-plug connected, with the receptacle in the adjacent cabinet and the cord passing through a protected hole. Hardwiring is common too, but "built-ins are always hardwired" is not accurate for US homes.

Time, skill and when to call a pro

A straight swap of an existing unit is a 2 to 4 hour job for someone comfortable with basic plumbing and wiring. Shut off the breaker and the under-sink valve first, fit a new supply line, secure the unit to the countertop or cabinet, and level it. Call a professional for a first-time installation where no dishwasher existed, since that means cutting the cabinet, running a new circuit and possibly pulling a permit, and for any doubt about the electrical work.

Replacing a machine means matching the existing opening. Adding one means creating an opening that was never there.

The price of the machine moves with size, tub material, noise rating, a third rack, hidden versus visible controls, a panel-ready door and the finish. An 18-inch slim model and a 24-inch standard sit in different places, a stainless tub costs more than a plastic one, and a quiet machine with hidden controls and a third rack sits above a basic front-control model.

Installation is the second line. A straight swap of an existing unit is the cheapest labor, because the plumbing, the circuit and the opening already exist. A first-time install costs more: it involves cabinetry work, a new circuit and possibly a permit. Hauling away the old machine is usually a separate charge.

Who does the work changes what you get. A retailer's installation service handles the swap and the haul-away in one visit. An independent installer is the usual route for a first-time job with cabinet work. Doing it yourself saves the labor but leaves you responsible for the water connection, the drain loop and the electrical work.

The federal maximum is 5.0 gallons per cycle, and ENERGY STAR models use about 30% less. The ENERGY STAR thresholds split by size: standard models with 8 or more place settings must stay at 3.2 gallons per cycle and 240 kWh per year or less, while compact models with fewer than 8 place settings must stay at 2.0 gallons per cycle and 155 kWh per year or less. That standard and compact split maps onto 24-inch and 18-inch built-ins.

The Department of Energy assumes about 215 cycles a year, which is how the annual figures are calculated. An efficient standard model saves roughly 3,800 gallons over its life compared with an old machine. A built-in also uses less water per cycle than washing a full load by hand.

The advantages come from being part of the kitchen rather than parked in it.

• Largest capacity of the home types.
• Out of the way: it uses no floor space and no counter space.
• Quietest of the types, thanks to the insulation and the cabinet enclosure.
• The most feature-rich category, with third racks, sensors and sanitizing cycles.
• You can use the sink while it runs.
• It adds to the kitchen's resale appeal.

The drawbacks are the flip side of a permanent installation.

• It needs a cabinet opening plus permanent plumbing and power.
• It takes up a cabinet's worth of storage.
• It is hard to move and stays with the house.
• Installation is a pro job for most people.
• It cannot be used freestanding.

Homeowners, families, anyone remodeling a kitchen and households that already have a 24-inch opening get the most from one. In an open-plan kitchen where noise carries to the sofa, the quieter build of a built-in matters more than the extra capacity.

Renters who cannot modify the kitchen are better served by a portable or countertop machine. Very small kitchens with no 24-inch opening can still take an 18-inch slim built-in. Anyone who needs a dishwasher that moves from one home to the next should look at a portable on wheels or a countertop unit instead.