Toto Home Additions & ADU Nationwide

Toto Home Additions & ADU: The San Jose Owner’s Guide

Rowan Construction Group San Jose installs Toto plumbing fixtures in home additions and ADU projects across the city, with typical ADU construction running $106,200-$259,600 and home additions from $53,100-$153,400 depending on square footage and fixture count. We stock Toto toilets, faucets, and shower systems for same-day installation once your addition’s rough plumbing passes inspection. Most San Jose homeowners discover their Toto fixture needs attention during the final walkthrough of an addition or ADU, when a toilet runs continuously, a shower valve delivers inconsistent temperature, or a lavatory faucet’s ceramic disc cartridge begins weeping at the base after the first month of use.

Call (669) 271-8644

Which Toto Models This Applies To

Toto’s residential line breaks into several series you’ll encounter in San Jose additions and ADUs. The Drake II and Ultramax II one-piece toilets dominate our installs for their 1.28 GPF Tornado Flush and Cefiontect glaze, which matters in hard-water areas like the Almaden Valley where mineral buildup is aggressive. The Soiree and Guinevere suites appear in higher-end Willow Glen additions with their skirted bowls and SoftClose seats. For shower valves, the TS220 series thermostatic mixing valves and TBMT series pressure-balancing units are what we rough in most often.

Identifying your Toto part requires the model number stamped on the toilet tank lid’s underside, or the spec sheet left by your original contractor. The flapper for a Drake CST744S is not interchangeable with the Drake II CST454CEFG despite similar names; the fill valve on pre-2015 models uses a different snap ring than current production. We carry both OEM Toto parts and Korky aftermarket equivalents that meet Toto’s spec, the Korky 528MP fill valve being our usual substitution for the TSU99A.X when lead time on OEM stretches past three days. Rowan Construction Group San Jose is an independent contractor, not affiliated with Toto.

Signs Your Toto Home Additions & ADU Is Failing

• Continuous running or phantom flushes. The flapper seal degrades from chlorine and hard water, or the fill valve’s float cup sticks in San Jose’s mineral-heavy supply. The toilet cycles every few minutes, spiking water bills and preventing the bowl from reaching its designed refill level for proper trap seal.
• Temperature swing or pressure drop in shower. The thermostatic cartridge’s wax motor loses calibration, or sediment from East San Jose’s older mains lodges in the pressure-balancing spool. The result is scalding-cold oscillation or a 40% flow reduction when a neighbor flushes.
• Weeping or staining at faucet base or handle. The ceramic disc cartridge’s lubricated seals dry out, or the O-ring gland hardens from heat cycling in south-facing ADU bathrooms. Water tracks along the spout or pools on the vanity, damaging the cabinet substrate below.
• Weak or incomplete flush despite full tank. The rim feed holes clog with calcium, or the flapper chain is kinked from improper adjustment during original install. Toto’s Tornado Flush depends on precise rim jet geometry; partial blockage defeats the siphon initiation.
• Seat loosening or lid cracking. The SoftClose hinge’s hydraulic damper fails, or the plastic bosses in the bowl deck fatigue from overtightening. In ADUs rented to tenants, this is often the first visible wear point from aggressive use.

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Replacement Cost & What’s Included

The range reflects access difficulty, not part quality. A second-story ADU shower with no service panel behind the valve costs more than a first-floor addition with removable drywall. Under Clause 1 of the Haven Standard, the written price you receive before we start includes all parts, labor, and the 365-Day Done Right Promise. No change proceeds without a signed change order, which is why our projects finish within a few percent of the agreed number across 4,000-plus jobs since 2007.

DIY or Call Us?

What you can safely check: verify the water supply angle stop is fully open, clean the aerator screen, or confirm the flapper chain has half-inch slack. These take five minutes and a towel.

Where DIY goes wrong: Toto’s skirted toilets require a proprietary mounting bracket and Unifit adapter that must be precision-aligned before the bowl drops; forcing it cracks the china. Thermostatic cartridges contain a wax motor calibrated to 2-degree accuracy; extracting one without the correct sleeve wrench scores the brass body and voids any remaining warranty. The ceramic disc in a lavatory faucet is spring-loaded under 60 PSI; without a back-up wrench on the valve body, you’ll twist the copper supply line in the wall. We’ve replaced three DIY-ruined Toto valves in San Jose this year alone, all of which cost more than the original service call would have.

Call (669) 271-8644 and we’ll schedule a free estimate. Our technicians arrive uniformed, background-checked, with a documented photo record of what we find and what we do.

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