A double vanity is useful when two people regularly need a basin at the same time and the bathroom has enough room for both to stand comfortably. A single vanity often makes better use of a limited wall, leaving more bench space, storage or circulation. The number of basins should follow the household routine rather than an assumption that two always means an upgrade.
For an Australian bathroom renovation, compare three things separately: the cabinet’s overall size, the usable space around each basin and the plumbing required. A wide single-basin vanity can provide generous shared storage, while a compact double may leave both users cramped. The most effective layout is the one that resolves the actual morning bottleneck.
Identify what causes the morning queue
Observe how the bathroom is used on an ordinary weekday. Are two people trying to brush their teeth simultaneously, or is one using the basin while the other needs the mirror? A second basin solves the first situation more directly than the second.
Consider how long each task takes and whether the routines overlap every day. A couple leaving home at different times may rarely use two basins together. A family preparing children for school may value simultaneous access more often.
Also identify the room’s other bottlenecks. If the toilet and shower share the same small room, privacy may prevent two people using the vanity regardless of basin count. A second basin does little if the room is occupied by someone who needs the door closed.
Use those observations to shape your bathroom renovation plan. It may reveal that extra mirror space, a separate grooming area or better storage would help more than duplicated plumbing.
Compare complete layouts, not basin counts
A single basin can sit within a generous cabinet
A single vanity does not have to be small. One basin on a wider top can leave substantial landing space for daily products and grooming tasks. An offset position may create a particularly useful clear area on one side.
That arrangement can suit a shared bathroom where one person needs water while another uses the mirror or prepares toiletries. Check where each person stands and whether drawers can be opened without interrupting the other.
A double basin needs two workable positions
Two basins provide two washing points, but each needs usable space around it. The basin shape, tap position, cabinet ends and gap between users all affect comfort. Overall width alone does not tell you whether the arrangement works.
Manufacturer ranges may offer single and double configurations within selected cabinet sizes. ADP’s Glacier Hamper range, for example, includes centre-basin and double-basin options in some wider formats. Product availability does not establish that every offered configuration suits every room or household.
Test the space between people as well as basins
Mark the proposed cabinet and basin positions at full size using a safe temporary outline. Have two users stand at them and imitate ordinary washing and grooming movements. Elbows, leaning forward and reaching for products use more space than a pair of circles on a plan suggests.
Measure the whole vanity wall
Record the distance between finished walls, door openings and nearby fixtures. Include architraves, towel rails, windows and any wall projections. A cabinet that fits the nominal wall length may still interfere with the entrance or a shower screen.
Check whether side fillers or installation clearances are needed for the selected product. Drawers and doors should open correctly beside a wall. A design measured tightly to the cabinet box can overlook the movement of handles or a projecting benchtop.
Measure the room depth too. Two users standing at a deep vanity can obstruct the route behind them. A double basin that uses the available wall neatly may still make the bathroom difficult to move through.
Review the small bathroom layout principles if space is constrained. Giving circulation a clear place in the plan helps prevent the vanity from dominating the room at the expense of everyday comfort.
Count clear benchtop space after fitting the basins
Place the chosen basin outlines on the proposed top. Then add taps, soap, toothbrush storage and any items that genuinely remain out. The remaining clear area is what you will use to put down a wash bag, glasses or a grooming tool.
Two large bowls can consume most of a medium-width top. A smaller basin may recover surface area, but check that it remains comfortable for washing and works with the tap. The goal is usable balance, not simply squeezing two fittings into a width.
An offset single basin can create one uninterrupted landing area. A centred single may create equal smaller areas on each side. Compare these against your habits: a clear space for a wash bag may be more useful than two narrow strips.
Our comparison of above-counter and inset basins explains how mounting style affects the surface and cabinet. Use the actual basin dimensions rather than a generic symbol when reviewing the layout.
Check storage below each washing point
A second basin adds another waste connection and may take space from the cabinet below. The exact effect depends on basin depth, plumbing layout and drawer design. A wide cabinet with two basins can still provide good storage, but its gross volume is not the same as usable capacity.
Ask for internal drawings showing drawer depths, cutouts and service spaces. Check whether a central cupboard houses plumbing or provides useful storage. A rendered cabinet front rarely reveals these details.
Give each regular user a practical storage zone where possible. This can be a drawer, a divided compartment or a section of a shaving cabinet. Separate storage may reduce clutter more effectively than separate basins.
If daily toiletries are small, consider recessed or wall-mounted shaving cabinets as part of the design. They can free the vanity top while keeping frequently used items within reach.
Coordinate taps and plumbing as one specification
A double vanity needs the appropriate water and waste arrangement for both basins. Have a licensed plumber assess the existing services and proposed positions before ordering. Do not assume a second basin can connect neatly within the current cabinet space.
Wall-mounted taps require particular coordination with finished basin positions and heights. Once concealed services and wall finishes are complete, correcting a mismatch can be disruptive. Basin-mounted taps have their own requirements for holes, reach and access.
The outlet should suit the basin’s shape and intended use. A pair of taps chosen for appearance can still splash or feel awkward if the reach and basin geometry are poorly matched. Ask the supplier and plumber to check the complete combination.
Review wall and basin-mounted tap arrangements during selection. Keep the approved product codes and dimensions together so the cabinetmaker, plumber and top fabricator work from the same information.
Make mirror and lighting space work for both users
Two basins do not automatically create two useful grooming positions. The mirror must serve both, and the lighting should allow each person to see comfortably without being blocked by the other. Consider the position of the users, not only symmetry above the cabinet.
A single broad mirror can suit a continuous vanity, while two separate mirrors can reinforce individual positions. Compare the visible wall between them and any adjacent storage. Neither approach should be chosen before checking eye levels and daily tasks.
If one person needs a seated grooming position, plan it deliberately. A standard vanity drawer arrangement may leave no knee space, and a second basin may remove the most useful area for that purpose. Advice tailored to the user can clarify a better configuration.
Any electrical work, including outlets and integrated lighting, should be designed and installed by a licensed electrician with the bathroom conditions in mind. Keep charging arrangements practical without placing everyday devices in unsuitable wet locations.
Compare cleaning and household habits
A second basin means another bowl, tap and waste area to clean. The additional work may be entirely worthwhile when both are used daily. It may feel less worthwhile if one becomes a permanent shelf for products.
Look at the gap between bowls and behind taps. A narrow space can be awkward to wipe, particularly with above-counter basins. Choose a layout that leaves access for normal cleaning rather than depending on a special tool for every corner.
Discuss how the household shares products. If both users reach for the same soap or toothpaste, place it where it is accessible without leaning across someone else. Separate basins can still share a well-positioned central storage point.
Consider water use through actual behaviour. Installing two basins does not by itself determine consumption; the selected fittings and how long they run matter. Ask the supplier for the relevant product information rather than assuming a basin count proves efficiency or waste.
Choose the cabinet mounting style separately
Single and double configurations can be available in both wall-hung and floor-standing designs. The mounting decision affects support, cleaning beneath the cabinet, plumbing visibility and the amount of lower storage.
A wider wall-hung unit needs an appropriately designed support arrangement for its complete specification. A floor-standing unit may conceal services more easily, but still needs the manufacturer’s required installation and restraint. Qualified installers should assess the actual wall and floor.
Our guide to wall-hung and floor-standing vanities covers those installation differences. Resolve them alongside basin count so the selected cabinet is practical to install, not merely attractive in elevation.
When replacing an existing unit, check what the new shape will expose. A smaller cabinet or open base can reveal missing tiles, old plumbing routes or wall damage. Include making-good work in the comparison.
Compare the additional cost of a second basin
The cost difference includes more than another bowl. It may involve a wider cabinet or top, another tap and waste, additional plumbing, altered mirrors and changes to wall finishes. Ask quotations to show these differences clearly and state whether GST is included.
For an illustrative comparison only, assume a specified single-basin vanity package costs AUD $2,000, its tap and waste allowance is AUD $350, and associated installation and plumbing cost AUD $750. With GST assumed included, that hypothetical partial scope totals AUD $3,100.
A hypothetical double package might allow AUD $2,700 for the vanity, AUD $700 for two tap-and-waste sets and AUD $1,100 for installation and plumbing, totalling AUD $4,500 including assumed GST. The example difference is AUD $1,400. These are planning figures, not current supplier prices or a national average.
Both examples exclude mirrors, electrical work, demolition and surface repairs. Add the actual shared and differing work to your complete bathroom renovation budget before deciding whether the extra washing position is worth the investment.
Compare three plausible household choices
For a compact ensuite used by two adults at different times, a generous single basin with clear landing space may provide the better daily experience. The spare width can support organised drawers or a wider mirror without increasing crowding.
For a larger shared bathroom where two people regularly brush teeth together, a double vanity may remove a repeated inconvenience. Its value is strongest when both users have comfortable standing room and the bathroom’s privacy arrangements permit simultaneous use.
For a family bathroom where children need assistance, the design may depend more on access and finished height than on basin count. A parent helping one child needs space beside the basin. A second bowl occupying that space may be less useful than expected.
These are illustrative household situations, not rules. Use them to test your assumptions against your own routine. The most convincing reason for two basins is a recurring need that the proposed layout can actually serve.
Approve the layout with real products
Before ordering, review the complete cabinet, basin and tap drawings. Confirm the finished dimensions, opening movements, service locations and mirror relationship. A late basin substitution can affect the top cutouts and the space left beneath.
Ask the supplier when changes become variations and when manufacture is committed. Keep one current schedule of approved products. This is particularly useful if you buy tapware separately from the vanity package.
At handover, test both washing positions if there are two. Check that drawers open, products can be reached and the agreed plumbing access remains available. Report leaks or misalignment to the responsible installer promptly.
- Confirm the layout serves the household’s real overlap in use.
- Check standing room and circulation with drawers open.
- Measure clear landing space after fittings are included.
- Review actual internal storage, not just cabinet width.
- Keep approved drawings, product records and care instructions.
A successful vanity gives the room enough water access, useful storage and comfortable movement. Choose a double when two working positions provide a clear everyday benefit. Choose a single when the freed space makes the bathroom easier to share, clean and enjoy.