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Toto Home Additions & ADU: The San Jose Owner’s Guide
If you’re planning a Toto-equipped home addition or ADU in San Jose, you’re looking at a total project range of $53,100 – $153,400 for the addition itself, with ADU construction running $106,200 – $259,600 depending on size, site conditions, and finish level. We install Toto fixtures and plumbing rough-ins as part of these projects every season, and the plumbing component typically accounts for $8,000 – $22,000 of the total. Most San Jose homeowners discover their Toto plumbing components are failing when water pressure drops in the new space, or when a fixture installed years ago starts leaking at the connection points and staining the subfloor.
This page covers what goes wrong, what it costs to fix or build right the first time, and how to know whether you’re dealing with a simple fixture swap or a bigger structural issue. Bradford Remodeling Co San Jose is an independent general contractor, not affiliated with Toto. Straight number, written scope, done when we said done.
Which Toto Models This Applies To
Toto’s product lines break into a few families that matter for additions and ADUs: the Drake and Drake II (1.6 and 1.28 GPF, standard 12-inch rough-in), the Ultramax II (one-piece, skirted, 12-inch rough-in), the Aquia wall-hung (concealed tank, in-wall carrier required), and the Washlet integrated units (electrical outlet needed within 3 feet of the bowl). The rough-in measurement is the compatibility gotcha: most Toto floor-mounts want a 12-inch rough-in from finished wall to center of the flange, but the Aquia and some Carlyle II models require a 10-inch or 14-inch rough-in. If the wall was framed wrong before tile went up, the toilet either won’t seat or sits too far off the wall, and you’ll fight the problem through every repair.
The OEM-vs-aftermarket decision for Toto comes down to this: Toto’s fill valves and flappers are engineered to work with Toto’s flush valve sizing. A universal flapper that works on a Mansfield will not seat correctly on a G-Max or E-Max flush valve, and you’ll get ghost flushing or a running toilet. We stock Toto OEM fill valves, flush valve assemblies, and trip levers on the truck for the common 1.28 GPF Drake and Ultramax models. For anything obscure, we source from Toto’s San Jose distribution network within two business days.
Key Takeaways
- 12-inch rough-in covers most Toto floor-mounts; Aquia and some Carlyle II need 10-inch or 14-inch.
- Universal aftermarket flappers fail on Toto G-Max and E-Max valves. Use OEM for flush components.
- Washlet installations need a dedicated GFCI outlet within 3 feet and accessible from the side.
- Wall-hung Toto units require an in-wall carrier, which adds $500 – $1,200 to rough-in plumbing.
Styles & brands we work with
Signs Your Toto Home Additions & ADU Is Failing
- Running toilet that won’t stop, even after jiggling the handle. The flapper or fill valve seal has worn or mineral deposits are preventing a seal. In San Jose’s hard water, calcium buildup on the flush valve seat is common by year five, and it causes the fill valve to cycle every 20 minutes.
- Water staining the ceiling below a second-story or ADU bathroom. The wax ring or the supply line connection has failed. What starts as a slow seep at the tank-to-bowl connection rots the subfloor silently, and by the time you see the stain, you’re replacing underlayment, not just the part.
- Flush is weak or incomplete, even though the tank fills fully. The rim jets are clogged with mineral scale, or the tank water level is set too low. Toto’s 1.28 GPF engines depend on velocity, not volume. When the jets clog, a flush that once cleared on the first try now leaves solids behind.
- Condensation or sweating on the tank in summer months. The tank-to-bowl gasket is leaking, or the fill valve is overfilling and cold water sits in the tank too long. San Jose’s dry summers don’t usually cause interior sweating unless water is moving where it shouldn’t be.
- Bowl doesn’t refill to the proper level after flushing. The fill valve is set wrong or wearing out. A bowl that runs low starts to smell because the trap seal isn’t maintained, and sewer gas seeps into the room.
See the difference
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After
Before
After
Before
AfterReplacement Cost & What’s Included
For Toto plumbing component repair or replacement within a home addition or ADU in San Jose, expect installed pricing in these ranges:
- Toto fill valve replacement: $180 – $320 installed, OEM part included
- Toto flush valve and flapper assembly: $240 – $410 installed
- Complete toilet swap (new Toto fixture, wax ring, supply line, haul-away): $590 – $1,180 installed, fixture cost separate based on model
- Full bathroom rough-in plumbing for an ADU (drain, vent, supply lines, toilet flange, shower valve): $4,700 – $9,400
- Whole-home addition plumbing rough-in (bath plus kitchen): $8,000 – $22,000
The range depends on access: a toilet swap in a first-floor bathroom with a clean shut-off valve is at the low end. A replacement that requires opening a wall to correct a wrong rough-in, or rebuilding a rotted subfloor before setting the flange, moves toward the high end. Every price is written before work starts. No numbers that move at the door. Our 365-Day Done Right Promise covers the workmanship and the parts we install for a full year: if a fill valve we put in fails inside that window, we come back and correct it at no charge.
DIY or Call Us?
You can safely check a few things: confirm the tank water level is at the marked line inside the tank, verify the shut-off valve at the wall turns freely (if it doesn’t, leave it alone until you call us), and check that the flapper chain has about a half inch of slack. When the chain is too tight, the flapper won’t seat, and the toilet runs. That’s the cause of a lot of “leaky toilet” calls in San Jose homes, and the fix takes ten seconds.
What goes wrong when homeowners try the full replacement themselves: the supply line nut cross-threads under the tank, the closet bolts get over-torqued and crack the porcelain base, or the flange turns out to be broken under the old wax ring and now you have a leak you can’t see. When the flange is cracked, you’re not replacing a part. You’re pulling the toilet, cutting out the old flange, and resetting everything on a solid substrate. That’s a job for a crew that’s done a few hundred of them. Call (669) 272-2637 if you’re past the chain adjustment.
FAQs
A Toto porcelain fixture itself commonly lasts 20 – 30 years or more, but the internal components – fill valve, flapper, flush valve seal – typically wear out in 5 – 8 years under San Jose’s hard water conditions. The porcelain rarely fails; the moving parts do. The good news is those parts are replaceable, and after a $240 – $410 service call, the fixture runs like new. If you’re hearing a persistent hiss or the toilet cycles at night, the fill valve is on its way out. Call (669) 272-2637 and we’ll give you a written price before we touch anything.
Fill valves, flappers, and trip levers are replacement parts, not repair candidates. The seals wear, and there’s no reliable way to rebuild a worn flapper material. What can be repaired on a Toto is the flush valve seat: mineral scale can be cleaned off the G-Max seat to restore a proper seal, and that’s a $180 – $320 service rather than a full flush valve replacement. Flush valves aren’t worth repairing. We replace them with OEM parts and the cost difference is small relative to the labor. The honest answer: repair what’s cleanable, replace what’s worn. Reach us at (669) 272-2637 for a straight assessment.
A fill valve or flapper replacement runs 45 minutes to an hour, including testing the flush cycle and checking for leaks at the supply connection. A complete toilet swap takes 1.5 – 2 hours when the flange is in good condition. If the flange is cracked or the subfloor is soft, that’s a half-day job that involves pulling the fixture, cutting out the bad section, and setting a new flange on solid wood. A full ADU bathroom rough-in with Toto fixtures runs 2 – 3 days for the plumbing phase. We’ll give you the timeline in writing before work starts.
We stock Toto OEM fill valves, flush valve assemblies, flappers, and trip levers for the Drake, Drake II, Ultramax, and Ultramax II models, which cover the majority of Toto units installed in San Jose homes over the past 15 years. We also carry wax rings, supply lines, and closet bolt sets for standard 12-inch rough-ins. Wall-hung Aquia replacement parts and Washlet components come by special order, usually within two business days from Toto’s Bay Area distribution. When you call (669) 272-2637, we’ll confirm the model over the phone and tell you whether the part is on the truck before we roll.
If you’re planning a Toto-equipped addition or ADU in San Jose, or you have a Toto fixture failing in an existing space, call (669) 272-2637 for a free estimate. We’ll give you a written price, a written scope, and a written one-year guarantee. That’s The Garrison Standard, and it’s the only way Curtis Lane and the Bradford Remodeling Co San Jose crew work.
Written by Curtis Lane, Owner, Bradford Remodeling Co at Bradford Remodeling Co San Jose, serving San Jose and nearby areas.
