Bidets and Bidet Seats: Planning Power and Water

A bidet is mostly a planning question. Whether you choose a seat that fits on a toilet, a toilet with the bidet built in, or a separate fixture, each needs water, and most need power, at a spot that is hard to reach once tile is on the wall. Deciding during the design means the outlet, supply and space are already where they need to be, even if you buy the bidet later.

The three kinds of bidet

Most remodels use a seat or an integrated toilet, because they fit in the toilet's existing footprint. A stand-alone bidet adds a fixture, which means a new drain and vent and more floor area. It is easiest to plan in a primary bathroom or a toilet room with space to spare.

Power: the outlet beside the toilet

Electric bidet seats and integrated bidet toilets plug into a receptacle near the toilet. If that outlet is not there, the choices after the remodel are an extension cord across the floor, which is unsafe and unsightly, or opening a finished wall. Adding it during the electrical rough-in costs little by comparison.

• Where to put it. Most seats have a short cord on one side, usually the right as you face the toilet. Check the model's installation drawing for the cord side and length, and place the outlet low on the wall beside the tank, within reach and away from where water could drip onto it.
• Protection. Receptacles in a bathroom must be GFCI protected under the electrical code. How the bathroom circuits are arranged, and whether the bidet outlet can share a circuit, is covered on our bathroom electrical code page.
• If you are not buying one yet. Put the outlet in anyway. A covered outlet behind the toilet is nearly invisible, and it keeps the option open for you or the next owner.

Water supply and backflow

A bidet seat connects to the toilet's cold water supply with a tee fitting at the shutoff valve, so the supply feeds both the tank and the seat. Before you buy, look at the shutoff valve. An old multi-turn valve that is stiff or weeping should be replaced first, and a remodel is the time to do it.

• Backflow. A bidet puts a spray nozzle inside the toilet bowl, so the fitting must keep bowl water from being drawn back into the drinking water supply. Bidet fittings are covered by the national plumbing supply fittings standard, ASME A112.18.1/CSA B125.1, which also covers faucets and showerheads. Choose a product certified to that standard and installed with the backflow protection its instructions call for, rather than a generic tee and hose from an unknown maker.
• Warm water. Electric seats heat water in a small tank or on demand. Non-electric models that offer warm water draw it from a hot line, usually teed from the sink supply, which means a hose running behind the vanity and toilet. Plan that route.
• Stand-alone bidets need their own hot and cold supply, drain and vent. That is new plumbing, done by a certified plumber or the homeowner on their own home, under a plumbing permit. See what plumbing changes involve.

Space and clearances for a stand-alone bidet

Washington's plumbing code treats a bidet like a toilet for spacing. Under the state's version of UPC 402.5 (WAC 51-56-0400), no toilet or bidet may be set closer than 15 inches from its center to a side wall or obstruction, or closer than 30 inches center to center to a similar fixture, and in a house the clear space in front must be at least 21 inches. In practice that means a toilet and a bidet side by side need a wall at least 60 inches long just for the two fixtures, before any vanity. The full set of clearances is on our bathroom plumbing code page. Designers often allow more than the minimum for comfort; the NKBA guidelines are a useful reference, but they are recommendations, not code.

Features worth comparing on electric seats

• Water heating. A storage tank keeps a small volume warm and can run cool on a long use. On-demand (instant) heating warms water as it flows and does not run out, but draws more power while running.
• Nozzle hygiene. Self-cleaning cycles, a retracting nozzle and a removable nozzle tip all help.
• Seat shape and length. The seat body sits behind the bowl opening, so the seat can be longer than the bowl. On a round bowl, check that the lid clears the tank when raised.
• Controls. A side panel is simple; a wireless remote mounted on the wall is easier for some people to reach. Large, clearly marked buttons help older users and guests.
• Night light, heated seat and dryer. Useful, but each adds electrical draw and parts that can fail.
• Power-off behavior. Check what works when the power is out. Most electric seats will not spray without power, though the toilet still flushes.

For people planning to stay in their home as they age, a bidet seat can make daily care easier and more independent. It pairs well with a comfortable toilet height and a sturdy grab bar; see aging-in-place bathroom design and grab bars and safety hardware.

What to check before you buy

1. The seat fits your bowl shape and model. Use the maker's fit list or paper template, especially for one-piece, skirted or wall-hung toilets.
2. The cord side and cord length, so the outlet goes on the right side and at a reachable height.
3. That there is (or will be) a GFCI-protected receptacle within reach, installed under a permit.
4. The shutoff valve at the toilet turns freely and does not drip, and the supply line is long enough after the tee.
5. Certification to the plumbing supply fittings standard and the backflow protection the instructions require.
6. For warm-water non-electric models: the hot supply route from the sink.
7. For an integrated bidet toilet: overall length against the clear space in front, the flush volume (1.28 gallons or less), and the rough-in.
8. For a stand-alone bidet: wall length for both fixtures with their clearances, and the drain and vent route.

Planning a bidet with JDI

When a bidet is on the list, or might be later, we add the outlet and supply to the drawings so the electrician and plumber rough them in before drywall, and we check the seat or toilet against the layout on the 3D design. Our designer, Denise Lacquement, can help you decide whether a seat, an integrated toilet or a separate fixture suits the room. To start, request a free in-home consultation.