Bathroom Vanity Buying Guide: Construction, Materials & Sizing

Cabinet construction: solid wood, plywood, or MDF

The cabinet box is the part of a vanity you never see and the part that decides how well it survives a humid bathroom. This Old House identifies three common materials: solid wood, plywood, and MDF (medium-density fiberboard), each with a real trade-off.

Solid wood is the most durable option but also the most expensive. Plywood is a strong middle ground, though its exposed edges need to be covered (typically with an edge banding or trim) and it produces more waste in fabrication. MDF is the budget-friendly choice and, contrary to its reputation, This Old House notes it is moisture-resistant and actually more efficient to fabricate than plywood — it is nondirectional, so a sheet is used more completely, and its treated edges don’t need the extra covering step plywood requires.

Fixr’s guide reaches a similar conclusion from the buyer’s side: "the most durable materials are solid wood and high-grade plywood," which resist moisture well when properly sealed. The practical takeaway is that MDF is not automatically the weak choice it is sometimes assumed to be — a well-made MDF cabinet with a good moisture-resistant finish can outperform a poorly sealed plywood one.

Clearances: the sizing rule that comes before style

Before configuration or style, a vanity has to physically fit the room with enough space to use comfortably. This Old House’s clearance guidance is a useful starting baseline: at least 30 inches of clear floor space in front of the vanity, and at least 15 inches from the center of any sink to an adjacent wall or fixture.

Those two numbers alone rule out a lot of vanities that look right in a photo but would crowd a real bathroom. Measure your actual clearances before you fall in love with a specific piece — it is far easier to change your mind on paper than after installation. An awkward room size is also one of the situations where going custom instead of prefab starts to earn its premium.

Single vs. double, and what it costs

A single-sink vanity is the default for most bathrooms — it is simpler to plumb, gives one person more usable counter and storage than a cramped double, and comes in the widest range of sizes. A double vanity needs meaningfully more wall width (so each sink has real counter space on the outside edge) and two full sets of supply and drain lines, which is a bigger consideration in an older home’s plumbing than in new construction.

On cost, Fixr’s figures give a useful anchor: a basic 60-inch vanity runs about $1,100 in materials, with installation running around $100 for a floor-mounted vanity versus $210–$280 for a wall-mounted (floating) vanity — floating vanities cost more to install because they need solid blocking in the wall to carry the weight without a cabinet base underneath.

Vanity vs. countertop: two separate material decisions

The cabinet box and the countertop on top of it are chosen independently and often get confused as one decision. Quartz, granite, marble, and solid-surface tops each have their own durability and sealing profile — that comparison lives in our bathroom vanity countertops guide rather than here, so this guide can stay focused on the cabinet itself.