Vanity Unit Buying Guide: Sizes, Wall Hung vs Floor Standing, and Materials

Choose wall hung for a small or modern bathroom where floor space shows. Choose floor standing for more storage, a stud wall you can't strengthen, or a simpler fit.

As a guide, 400–500mm suits a cloakroom or small en-suite and 600mm is the usual size for a main bathroom; go wider only if there's still room to walk past. Depth matters as much as width in a small room: allow roughly 700mm of clear standing space in front of the basin, and check that the unit's doors or drawers can open past the WC and the bathroom door.

• Go shallow. SCN's Classic cloakroom units are just 220mm deep, against about 470mm for a full-size 600mm unit.
• Use the corner. A 410 x 410mm corner unit fits where a square one can't and leaves the walls free.
• Lift it off the floor. A wall hung unit shows more floor, which makes a small room feel bigger.
• Lose the handles. Handleless fronts, like SCN's Phoenix and Pearl, don't catch hips and towels in a tight room.
• Size the tap to the basin. A small cloakroom basin needs a compact mixer that won't splash over the edge.

Most vanity units are MDF or MFC (chipboard) with a gloss, painted or wood-effect finish such as oak. They look good, but they're only as waterproof as their edges: once water gets past a chipped edge or a tired seal — round the basin, at the plinth, under the trap — the board swells, and it can't be put right.

SCN's Aqua range is built from 100% waterproof PVC instead, so it can't swell, warp or rot however steamy the room or however often the floor gets splashed. It's the one we'd pick for a family bathroom, an en-suite with no window, or a rental. The 600mm Aqua wall hung unit with basin is £402.54; the 600mm Phoenix in gloss white is £379.26. Both carry SCN's 10-year warranty.

• Tap holes. One tap hole takes a monobloc mixer, two take a pair of pillar taps, and none means a wall-mounted tap. Most vanity basins are one tap hole, but check before you buy taps.
• Waste. Basins take a 32mm (1¼") waste: slotted if the basin has an overflow, unslotted if it doesn't. Many mixers include one — SCN's Standard basin mixer at £38.79 comes with a click-clack waste and flexible tap connectors.
• Trap. A 32mm bottle trap is the usual choice inside a vanity unit: compact, and it unscrews for cleaning. A telescopic one, like the SCN 1¼" bottle trap at £5.81, adjusts in height to meet the waste pipe. With a drawer unit, check the trap clears the drawer before you fix it.
• Pipe runs. Plan where the supplies and waste come through the wall so they land inside the unit. Our waste pipe sizes guide covers sizes and falls.

A back-to-wall WC unit is a cabinet that hides a concealed cistern, with a back-to-wall pan standing in front, so only the pan and the flush button show. Ours are 500mm wide in the SCN Classic, Phoenix and Aqua ranges, to sit alongside the vanity units for a fitted run. The cistern and pan are bought separately: the SCN concealed cistern is WRAS approved and £38.79, and back-to-wall pans are on the WC pans shelf. Plan how you'll reach the cistern's valves for servicing before the unit goes in.

1. Check the wall. A solid knock means masonry; a hollow one is a stud wall, which needs timber noggins or a plywood pattress between the studs, fitted before it's boarded, to take the screws.
2. Scan for pipes and cables with a detector before you drill.
3. Mark the height. Most people set the basin at roughly the height of a floor-standing unit — ours are 860–870mm to the top — and draw a level line for the brackets.
4. Fix the brackets with fixings rated for the wall and the load: the unit, the basin, the water and someone leaning on it.
5. Hang and level the unit, connect the waste and the supplies through isolating valves, and seal the basin to the wall with sanitary silicone.

Rather have it fitted? Our supply & fit service covers Greater London.

There are 31 basins, vanity units and WC units on the basins and vanity units shelf.