Bathroom Remodeling
Double Vanity Installation in Orange County
4 min read
Double vanity installation converts a single-sink bathroom into a two-sink setup, which requires a second supply pair, a second waste connection tied into the existing branch with correct slope and venting, and enough wall length to make both stations usable. The plumbing is the real work; the cabinet is the easy part. Most Orange County primary bathrooms built after 1985 already have a 72 inch or wider vanity wall and often a second rough-in stubbed but capped. Older homes in Fullerton, Orange, and Anaheim typically have a 48 to 60 inch wall with a single center drain, and those projects require opening the wall to run new pipe.
About 4 min left
How wide does a vanity wall need to be for two sinks?
Sixty inches is the practical minimum and it is genuinely tight. At that width each bowl sits roughly 15 inches off its respective end, leaving about 18 inches of counter between them, which two adults will find cramped when both are standing at the mirror. Seventy-two inches is the comfortable standard: each bowl centered about 18 inches from its end, with 30 inches of open counter in the middle for a shared drop zone or a bank of drawers below. Eighty-four inches and up allows a genuine center tower or a makeup station with a knee space. Below 60 inches, a single sink with generous counter almost always serves better than two crowded bowls. We measure the actual wall and tell you which category you are in before anything is designed.
What plumbing work does adding a second sink involve?
A second lavatory needs hot and cold supply, a waste connection, and venting. The waste is the constraint. Two lavatories can share a vent when they are within the distance the code allows for the trap arm and the tie-in is made correctly, but the tie-in point still has to maintain proper fall toward the existing branch. That usually means opening the wall between the two sink locations, running new drain pipe with 1/4 inch per foot of fall, and tying in with a sanitary fitting rather than a straight tee. On slab-on-grade homes the horizontal run happens in the wall rather than the floor whenever possible, because opening a slab is far more expensive. We verify vent capacity and confirm the tie-in method before quoting.
Where should the sinks and mirrors actually go?
Sink placement drives everything else on the wall. Each bowl wants at least 15 inches from its centerline to the nearest side wall or obstruction, matching the same clearance principle California Plumbing Code sets for toilets, and 30 to 36 inches between the two bowl centerlines is what keeps elbows from colliding. Faucet spouts should clear the bowl rim comfortably, which is a real consideration with vessel sinks and wall-mounted faucets. Mirrors are usually cleanest as two separate units centered over each bowl rather than one continuous mirror, because a continuous mirror puts a light fixture in an awkward position at the center. Sconces at face height flanking each mirror produce far better light for shaving and makeup than a single overhead bar, which casts shadows straight down.
Is converting a single vanity to a double worth it?
It depends on the household and the resale profile. Two adults sharing a primary bathroom on the same morning schedule get real daily value, and in Orange County move-up markets like Tustin, Yorba Linda, Mission Viejo, and Irvine, a single sink in a primary suite reads as dated to buyers. Where it is not worth it is a bathroom under 60 inches of vanity wall, a household where only one person uses the room, or a case where the second sink would come at the cost of the only meaningful counter space. We also flag the honest tradeoff: two bowls means two of everything to clean, less usable counter, and less cabinet interior because two traps intrude into the storage.
Scope
What's Included
Everything below is written into your scope of work before construction starts. Anything outside it requires a signed change order first.
- Wall measurement and spacing plan: Vanity wall measured and bowl centerlines laid out to keep at least 30 inches between sinks and 15 inches to each side obstruction.
- Existing rough-in evaluation: Inspection for a capped second stub, assessment of vent capacity, and determination of where the new drain can tie in.
- Second supply and waste rough: New hot and cold lines plus drain run at correct fall, tied in with proper sanitary fittings and vented to code.
- Wall opening and patch: Drywall opened along the pipe route, then patched, textured to match, and prepared for paint after inspection.
- Cabinet set and secured: Vanity leveled in both directions, shimmed, scribed to the wall, and fastened into framing or added blocking.
- Countertop with dual undermounts: Top templated after cabinet set, fabricated with two sink cutouts, then installed with bowls secured and sealed.
- Two faucet sets and drains: Both faucets mounted, pop-up or grid drains installed, traps connected, and each station individually leak tested.
- Lighting and mirror installation: Sconces or vanity fixtures positioned at face height for each station, plus mirrors hung level and centered on each bowl.
How it works
Our Process
Every project follows the same structured sequence, so you always know what happens next and who to call.
Wall measure and feasibility check
45 minutesWe measure the vanity wall, open an access point where possible to see the existing drain and vent, and confirm whether two sinks fit comfortably.
Layout and cabinet specification
3 to 7 daysBowl centerlines, drawer configuration around two traps, mirror and lighting positions, and countertop dimensions are finalized and approved.
Permit and material ordering
2 to 6 weeksThe plumbing permit is filed with your city while cabinetry, faucets, sinks, and lighting are ordered so nothing delays the rough-in.
Demolition and plumbing rough
2 to 3 daysThe old vanity comes out, the wall is opened along the pipe route, new supply and waste are run at proper fall, and the work is inspected.
Patch, cabinet set, and template
2 days, then 7 to 12 daysDrywall is patched and textured, the cabinet is set and leveled, and the countertop fabricator templates the same week for slab fabrication.
Top, fixtures, and lighting
1 to 2 daysCountertop and undermount bowls are installed, both faucet sets and drains connected and leak tested, then sconces and mirrors are mounted.
Budget
What does it cost?
Real ranges, stated up front. Your written proposal replaces these estimates with fixed numbers for your actual scope.
Typical range
$6,500 to $19,000
per double vanity
Estimate range for Orange County double vanity installations in 2026, including cabinet, stone top, two sinks and faucets, plumbing rough-in, and labor. Homes needing a new drain run and vent work sit toward the upper half.
Typical timeline: 3 to 5 weeks including cabinet and countertop lead time
What moves the price
- Whether a second rough-in already exists: Homes built after roughly 1985 sometimes have a capped second stub, which removes most of the plumbing labor. Older homes require opening the wall and running new drain and supply.
- Venting solution required: If the existing vent cannot serve a second fixture within code distance, the project needs a new vent run to the roof or an approved air admittance valve, each with different cost and inspection implications.
- Cabinet width and drawer configuration: A 72 inch cabinet with a center drawer bank costs meaningfully more than a 60 inch cabinet with doors, and drawers must be notched around two traps rather than one.
- Countertop size and material: Wider tops with two undermount cutouts use more slab, and stone with two polished cutouts and a mitered edge carries higher fabrication labor than a single-bowl top.
- Wall repair and finish matching: Opening drywall along the pipe route means patching, matching existing texture such as knockdown or orange peel, and repainting the full wall for a seamless result.
- Lighting reconfiguration: Moving from one overhead fixture to sconces at each station requires new switch legs and boxes at face height, which means opening the wall above the counter as well.
Compare
Compare your options
Side by side, so you can weigh cost against how long it lasts and how much upkeep it needs.
| Option | Cost | Durability | Maintenance | Best for |
|---|---|---|---|---|
| Undermount porcelain bowls | $140 to $400 each | Very high, glazed surface resists staining | Low, wipe-down cleaning with no rim to trap grime | Nearly all double vanities, and the easiest configuration to keep clean |
| Integrated quartz bowls | Adds $600 to $1,600 to the top | Very high, no seam between bowl and counter | Very low, nothing to reseal or recaulk | Contemporary primary bathrooms wanting a completely seamless surface |
| Vessel sinks | $200 to $900 each | Good, though exposed edges are vulnerable to chipping | Higher, the base ring collects water and film | Design-led bathrooms where the sink is meant to be a visible object |
| Cultured marble double top | $45 to $80 per sq ft installed | Moderate, integral bowls eliminate seams | Low, buffing removes light scratches | Secondary bathrooms and budget-conscious primary suites |
Answers
Frequently asked questions
How wide does a vanity need to be for two sinks?
Sixty inches is the workable minimum and it feels tight, leaving about 18 inches between the bowls. Seventy-two inches is the comfortable standard, giving each bowl clearance and roughly 30 inches of shared counter. Below 60 inches, a single sink with generous counter space serves most households better.
How much does it cost to add a second sink in Orange County?
Double vanity installation in Orange County generally runs $6,500 to $19,000 in 2026 including cabinet, stone top, two sinks and faucets, plumbing rough-in, and labor. Homes with an existing capped second rough-in sit at the low end; those needing new drain and vent work sit higher.
Do two sinks need separate drain lines?
Each sink needs its own trap and trap arm, but the two can commonly share a vent and tie into the same branch drain when the fixtures are within the distance code allows. The tie-in must maintain 1/4 inch per foot of fall and use proper sanitary fittings rather than straight tees.
How far apart should double vanity sinks be?
Plan 30 to 36 inches between bowl centerlines so two people are not colliding, with at least 15 inches from each bowl centerline to the nearest side wall or obstruction. On a 72 inch vanity, centering each bowl about 18 inches from its end achieves both comfortably.
Does a double vanity add value to an Orange County home?
In move-up markets such as Tustin, Yorba Linda, Mission Viejo, and Irvine, a single sink in a primary suite reads as dated to buyers, so a double vanity removes an objection. In smaller homes and secondary bathrooms the value is more neutral, and counter space may matter more.
Will adding a second sink reduce my storage?
Yes, somewhat. Two traps intrude into the cabinet interior instead of one, which eliminates some of the space directly beneath each bowl. Good custom cabinetry recovers much of it with U-shaped drawers that wrap the plumbing, and a center drawer bank between the bowls adds storage a single vanity does not have.
One large mirror or two separate mirrors?
Two separate mirrors centered over each bowl is usually the better choice, because it allows sconces at face height flanking each station. Face-height side lighting eliminates the downward shadows a single overhead bar creates, which is exactly the light you need for shaving and makeup.
Next step
Get a written quote for double vanity installation
Book a free consultation. We walk the space, talk through what you want, and send a written scope with real numbers. No pressure and no obligation.
Licensed and insured. Written scope before work begins. Weekly progress updates with photos.
What happens next: we reply the same business day, schedule a walkthrough, then send your written proposal.