Replacing a pedestal sink
with a vanity.

Choose the size by two things: the sink tops you can buy, and the space in your bathroom. Find the top first, then the base that takes it.

Our Rustic Bathroom Vanity Base comes in four sizes, each 32″ tall:

A sink top is about 1″ wider than its cabinet and ½–1″ deeper, which is why each size takes the top beside it in the table.

With a sink top on it, the counter stands 32″ plus the top’s thickness. Cultured marble tops are commonly about ¾″ thick (some 1⅛″), and stone tops come in 2 or 3 cm slabs (about ¾″ or 1¼″), so expect the counter at about 32¾–33¼″.

For a tight space, our note on small bathroom vanity sizes covers the narrowest vanities and what fits a half bath.

Before you order or build, measure:

• —The width of the space: wall to wall, or to the toilet or tub beside it. Leave room to walk past and to open the bathroom door.
• —The depth: from the wall to where the front of the sink top will be.
• —The plumbing: how high the supply valves and the drain come out of the wall, and how far each is from the middle of the space, so they fall inside the cabinet’s open back.
• —The floor: whether the drain comes up through the floor instead of the wall.
• —The top: choose the sink top first, and check its size against the base’s.

And the clearances: the minimums in the International Residential Code (IRC), the model code most US states base their house codes on, and the roomier ones the National Kitchen & Bath Association (NKBA), the kitchen and bath designers’ trade group, recommends:

• —From the toilet: the code asks for at least 15″ from the toilet’s centerline to the side of the sink top, the vanity’s nearest edge, and at least 30″ between the toilet’s centerline and the sink’s. On a top narrower than 30″, with its basin centered, the 30″ is the one that counts: our 24″ Rustic Bathroom Vanity Base’s 25″ top needs the toilet’s centerline at least 17½″ from its side, and the 18″ base’s 19″ top 20½″. The NKBA recommends 18″ where the code asks less. Some states and towns change these rules, so check your local code, and make sure you can sit on the toilet without feeling cramped.
• —In front: the code asks for at least 21″ clear in front of the sink and the toilet, to any wall, fixture or door, and the NKBA recommends 30″ to anything opposite.
• —Doors: check that the bathroom door and the vanity’s own doors open without hitting anything.

Fig. 1Plan · clearances

Usually, yes. The back of our Rustic Bathroom Vanity Base is open from 6½″ above the floor up to 28½″, across the cabinet’s full inside width (2″ less than its width).

A pedestal sink’s drain usually comes out of the wall about 20–21″ above the floor, with the supply valves at about 24″ (Kohler’s pedestal sheets, for example). A vanity’s rough-in sits a little lower: the drain at about 18–20″ and the supplies at about 20–22″. Either way, they fall inside that opening.

Fig. 2Back · the open back

The new sink’s drain may not sit at the old one’s height. Tailpiece extensions (short lengths of drain pipe, stock at the hardware store) make up the difference down to the trap, the U-bend under the sink. The plumbing code allows up to 24″ of drop from the sink’s drain outlet to the trap’s weir, the lip the water spills over inside it.

Call a plumber when the drain or supply pipes have to move, or the drain comes up through the floor. And if the old shutoff valves won’t close fully, or drip when you turn them, have them replaced before the swap.

Plumbing (supply lines, drains, venting, shutoffs) must be installed to your local code, and we recommend a licensed plumber. A permit may be required.

Before you start, expect some patching: flooring is often laid around a pedestal rather than under it, which can leave a bare patch where it stood, so check that the vanity covers it. The wall behind a pedestal is often unpainted, with holes from the old sink’s wall bracket. Then:

1. 01Shut off the water, and disconnect the supply lines and the drain.
2. 02Take out the old sink and its pedestal.
3. 03Patch and paint the wall the old sink covered, wherever the new top won’t hide it.
4. 04Set the base level, and screw its upper back rail to the wall studs.
5. 05Fit the faucet to the sink top, set the top on the base, then connect the supply lines and the drain, and check for leaks.
6. 06Run a bead of silicone where the top meets the wall.