Can I Turn My Vanity Into a Double Vanity?

If you’ve got a single vanity now and you’re wondering whether a double will fit in the same spot, the short answer is: often, yes. In most bathrooms, the old vanity comes out and a double vanity goes in that exact position, using the water and waste connections that are already there. It comes down to one measurement, and one detail about your plumbing that’s worth checking before you get too far into planning.

Two styles, same plumbing principle

A double vanity isn’t just one look. It can be two separate basins sitting on or inset into the benchtop, or a one-piece porcelain top with two bowls moulded into it as a single unit. Which one suits you is mostly about the finish you want and your budget, not the plumbing: either style needs the same two things underneath, a tap and a waste for each bowl.

The measurement that decides it: length

Before anything else, it’s a question of space. A double vanity needs more width than a single, and as a general guide, you’re looking at around 1200mm or more to fit two bowls comfortably. If a vanity that size, or larger, can physically fit where your current one sits, a double is usually achievable without changing the layout of the room. If the space is narrower than that, a double vanity won’t sit right, though there are other options worth talking through on site rather than ruling it out from a tape measure alone.

You don’t need to start the plumbing from scratch

This is the part people often assume is the hard part, and it usually isn’t. The water supply already running under your sink can be adjusted to suit two bowls and two taps instead of one. It’s not a case of running entirely new pipework through the wall; it’s extending and reconfiguring what’s already feeding your current vanity.

The waste works the same way. The drain pipework underneath the sink can also be adjusted to allow for two drains instead of one, again using the existing plumbing as the starting point rather than needing a completely new setup.

The one thing that can complicate it: where your hot and cold come out of the wall

This is the detail that actually decides how straightforward the job is, and it’s easy to miss if you’re only thinking about the vanity itself.

• If your hot and cold water lines come out of the wall below the vanity, inside the cabinet space, adjusting them to feed a second tap is a straightforward job. The pipework’s accessible without disturbing anything else in the room.
• If your hot and cold water lines come out of the wall above the vanity, behind the splashback or mirror, it’s a different story. Getting to that pipework to move it or add a second connection point usually means removing tiles. At that point, it’s no longer a simple vanity swap; it becomes a small tiling job as well as a plumbing one, which changes both the timeframe and what’s involved.

Neither situation rules out a double vanity. But it’s the difference between a straightforward day’s work and a job that needs tiling factored in, so it’s worth knowing which one you’ve got before you commit to a plan.

What it actually takes to find out

There’s no shortcut past measuring the real layout. We look at the available length, where the current water and waste connections sit, and whether your hot and cold lines exit above or below the vanity. That combination tells us exactly what’s involved, rather than guessing from the outside and finding out the hard way once the old vanity’s already out.

Thinking about a double vanity in your bathroom? We measure the current layout and tell you exactly what’s involved before anything is ordered or removed, then install the double vanity for you, whichever style you go with. Our vanity replacement team covers this across the Northern Beaches and North Shore. If you’re weighing up a bigger refresh at the same time, our bathroom renovations team can help with the whole room.