Bathroom Vanity Shop Drawings: Dimensions, Details, and What Fabricators Need

A bathroom vanity looks simple on paper — a cabinet with a sink and a countertop. In practice, the shop drawing for a custom vanity has to resolve more coordination conflicts than almost any other single millwork unit on a project. Plumbing rough-ins, drain locations, countertop material edge profiles, mounting structure, ADA clearances, and hardware schedules all have to live in the same document — and any gap shows up on installation day when the plumber and the millwork installer are standing in the same room.

The goal of this guide is to cover every dimension and detail that needs to be in a bathroom vanity shop drawing before it goes to fabrication — or before it goes to the architect for review. Our cabinet shop drawing services cover all of these elements as part of every standard package.

Standard Bathroom Vanity Dimensions

Before detailing the drawing contents, here are the standard dimension ranges that the drawings need to document for every unit:

These are the dimensions the drawing must document explicitly — not "per field conditions" or "verify with plumber." Custom vanity shop drawings need exact numbers that everyone on the project can rely on.

Plumbing Rough-In Coordination: The Most Commonly Missed Detail

In my experience, more vanity installations run into trouble at the plumbing coordination point than anywhere else. The shop drawing has to show exactly where the plumbing lives — not just where the vanity sits — so the plumber's rough-in and the cabinet's interior configuration don't conflict.

Drain rough-in location. For a single-sink vanity, the drain centerline is typically 12″–14″ from the nearest side wall. For a double-sink, each drain is located at roughly 1/4 and 3/4 of the vanity width. These dimensions must be shown on the plan view with reference to the finished wall face, not the rough framing. If the drawing references rough framing and the drywall thickness changes, every dimension shifts.

P-trap clearance. The P-trap occupies real space below the sink bowl. The shop drawing cross-section must show the P-trap envelope — typically 12″–15″ wide, 8″–10″ tall — and confirm that no drawer box, shelf, or fixed partition conflicts with it. This is the detail that kills drawer configurations: a vanity designed with a full-height drawer directly below the sink bowl has a problem that shows up on installation day.

Supply line stub-outs. Hot and cold supply lines are typically at 8″ above finished floor, 3″–4″ from the drain centerline on each side. The shop drawing must show the supply line locations relative to the base cabinet interior and confirm that the back panel has access holes at the correct locations.

Floating (Wall-Hung) vs. Floor-Mounted: Different Details for Each

The mounting method fundamentally changes what the shop drawing needs to show, and both types require details that go beyond the cabinet itself.

Floor-mounted vanities need toe kick dimensions (standard: 3½″ high × 3½″ deep), floor attachment method, and leveling leg or adjustable base detail if used. The floor finish must be shown running under the toe kick or stopping at the cabinet base — this affects the finish contractor as much as the millwork installer.

Floating vanities require a wall blocking detail. The drawing must show:

• Wall substrate requirement (typically ¾″ plywood backing, minimum 8″ tall, located at the mounting rail height)
• Mounting rail type — heavy-duty aluminum wall rail or concealed metal bracket system — with rail dimensions and fastener schedule
• Finished floor clearance (typically 6″–14″ from finished floor to bottom of cabinet)
• Load capacity note — a 72″ double-sink vanity with stone countertop can weigh 150–200 lbs before any user weight, and the blocking specification must reflect this

Many architects specify floating vanities for the ADA accessible appearance, but the drawing detail is the piece that makes the installation actually work. A floating vanity with no blocking detail is an architectural drawing, not a shop drawing.

Sink Cutout and Countertop Integration

The countertop is technically a separate scope from the cabinet in many projects, but the shop drawing must address the interface between them. At minimum, the drawing needs:

Sink cutout dimensions. Cutout location from the front edge (typically 2″–3″), from each side, and from centerline. For undermount sinks, the cutout must match the sink's template — the drawing should reference the sink manufacturer and model number so the fabricator uses the correct template. Drop-in sinks have their own rim dimensions that are not interchangeable.

Countertop edge profile. The edge profile (eased, bullnose, ogee, waterfall) must be called out in the drawing. Edge profile affects the countertop overhang at the front of the cabinet — a standard 1½″–2″ overhang at the front and sides — and must be dimensioned.

Faucet hole locations. Even if the plumber drills the faucet holes in the countertop, the shop drawing must show the faucet centerline location relative to the sink so the rough-in can be coordinated. Standard single-hole faucets require a 1⅜″ diameter hole; 3-hole faucet configurations need holes spaced at standard 4″ or widespread 8″–16″ center-to-center.

Face Frame vs. Frameless Construction

The construction type affects dimensional relationships throughout the drawing and must be explicitly stated.

Face frame construction: The drawing shows face frame member dimensions — typically 1½″ stile width and 1¾″ rail width. Door and drawer reveal dimensions are shown (inset, half-overlay, or full overlay). Face frame construction adds approximately 1½″ to the interior width of door openings and typically provides more rigid attachment to the wall. Common in US residential and traditional commercial projects.

Frameless construction: No face frame members. The drawing shows door and drawer gap dimensions (typically 1/8″ between adjacent doors, 3/32″ between door and drawer). European-style concealed hinges are standard. The carcase panel is the structural element, so panel thickness — minimum ¾″ — must be confirmed in the notes. Common in contemporary residential and commercial hotel/hospitality vanities.

The construction type also affects the hardware schedule: frameless construction requires different hinge types than face frame, and the drawer slide mounting points differ based on carcase vs. face frame attachment. See our cabinet shop drawings guide for the full hardware schedule requirements that apply to all cabinet types including vanities.

ADA Accessible Vanity Requirements in Shop Drawings

For commercial projects, ADA-accessible vanity units require specific dimensioning that must appear in the drawing. The 2010 ADA Standards for Accessible Design (Section 606 for lavatories) specify:

• Counter surface height: 34″ maximum above finished floor
• Knee clearance: 27″ high minimum × 30″ wide minimum × 19″ deep minimum below the counter
• Clear floor space: 30″ × 48″ centered on the unit
• No base cabinet below the counter in the knee clearance zone (or removable cabinetry with finished floor underneath)
• Exposed supply and drain pipes insulated or covered to prevent contact burns
• Faucet hardware: operable with one hand without tight grasping, pinching, or twisting — lever-style, loop, or push-type handles comply; round knobs do not

The shop drawing should call out ADA-accessible units explicitly in the title block and include a dimension callout confirming the 27″ knee clearance and 34″ maximum counter height. Any counter-level plumbing pipes must show insulation or protective cover details.

For projects that require both standard-height and ADA-height units in the same run — common in commercial restrooms — the drawing must clearly distinguish which units are accessible and which are not, typically with a unit designation table. For broader ADA dimensional requirements across all millwork types, see our article on ADA compliance in millwork drawings.

Hardware and Finish Schedule

Like all cabinet shop drawings, the vanity package needs a complete hardware schedule. For vanities specifically, this includes:

• Hinges: manufacturer, model, finish, overlay amount, and clip-on vs. press-in installation
• Drawer slides: manufacturer, model, extension type (full, 3/4), weight rating, and soft-close specification
• Pulls/knobs: manufacturer, model, finish, projection from face (important for ADA grip compliance), and mounting screw spacing
• Waste basket pullout: manufacturer, model, and carcase opening dimensions if included
• Lazy Susan or corner unit hardware (if applicable)

The finish schedule must list the cabinet exterior finish, interior finish, and countertop material with finish separately. Vanity environments involve humidity — finish specifications must be appropriate for wet areas. Waterborne finishes with a sealer are standard; catalyzed lacquer or conversion varnish are common in commercial hotel applications.

For bathroom vanity shop drawing rates, scope and complexity drive the estimate more than unit count — a single ADA-accessible floating vanity with stone top and integrated plumbing coordination typically takes more drawing time than three standard floor-mounted units.

Frequently Asked Questions