Toto Home Additions & ADU Nationwide

Toto Home Additions & ADU: The Boca Raton Owner’s Guide

Rowan Construction Group Boca Raton installs Toto fixtures and rough-in components in home additions and ADUs across Palm Beach County, with typical projects running $45,000-$130,000 for additions and $90,000-$220,000 for detached ADUs. Every quote is written, itemized, and signed before framing begins. Most Boca Raton homeowners discover their Toto plumbing rough-in or fixture placement needs correction when the addition slab is already poured or when the ADU’s compact footprint forces a layout rethink that the original Toto spec doesn’t accommodate.

Call (754) 254-8065

Which Toto Models This Applies To

Toto’s residential lines most commonly specified in Boca Raton additions and ADUs include the Drake II, Ultramax II, and Washlet-compatible Connect+ systems. The critical compatibility point is the rough-in measurement: 10-inch, 12-inch, or 14-inch from finished wall to center of flange. We’ve found that ADU plans drawn for standard 12-inch rough-ins often conflict with Toto’s skirted designs, which require additional clearance for the UniFit adapter. The model number is stamped on the tank interior or the underside of the bowl rim, prefixed with CST, MS, or MW.

For OEM versus aftermarket: Toto’s proprietary flush valves and fill valves (THU500S, THU331S) perform measurably better in Boca Raton’s hard water than generic equivalents, which tend to scale shut within 18 months. We source Toto direct or through Ferguson Boca Raton. For flange spacers, wax rings, and supply stops, we use Sioux Chief or Oatey brass, which meet the same pressure spec at lower cost. We don’t install unbranded valves in Toto tanks; the flush performance degrades enough that callbacks exceed the part savings.

Signs Your Toto Home Additions & ADU Is Failing

• Weak or incomplete flush in the new addition bathroom. The Toto’s 1.28 GPF flush valve may be undersized for the branch line length in a rear addition, or the vent stack wasn’t extended per Florida Plumbing Code. We measure actual flow rate at the rim and compare it to the fixture’s MAP score.
• Constant hissing or water cycling at the Toto fill valve. The Korky or Toto OEM fill valve is failing to seat fully, usually from sediment in Boca Raton’s municipal supply or from over-tightening during the original install. Left unaddressed, it adds $8-$15 monthly to the water bill.
• Rocking or seal failure between bowl and flange. In ADU slabs poured during humid summer months, the concrete cures unevenly and the flange sits high. The Toto’s skirted base has no access to shim; the fix is a flange extension or a re-pour of the closet bend area.
• Washlet seat connection loose or non-functional in the ADU. The Connect+ D-shape seat requires a dedicated 15-amp GFCI within 3 feet, which many ADU electrical plans omit. The symptom is a dead remote or intermittent heating; the cause is usually circuit loading, not the seat itself.
• Slow drain despite clear trap and line. Toto’s glazed trapway (SanaGloss or CeFiONtect) resists buildup, but the 3-inch waste opening meets a 2-inch ADU branch in some older Boca Raton neighborhoods. The restriction is in the transition fitting, not the fixture.

Before

After

Replacement Cost & What’s Included

The range depends on slab type (post-tension requires X-ray locating at $180-$320), access (crawl space versus finished ceiling below), and whether the original plumber left service loops. Our price includes the Toto OEM part or equivalent, brass supply stops, new wax ring or fluidmaster seal, water test, and photo documentation. Under Clause 1 of The Haven Standard, the number on the quote is the number on the invoice unless you sign a change order. The 365-Day Done Right Promise covers all installation labor.

DIY or Call Us?

What you can safely check: the supply stop rotation (turn off, turn on, listen for grinding), the tank-to-bowl bolt tightness (hand-tight plus quarter turn, no more), and the flush handle chain slack (half-inch of play). These are diagnostic, not fixes, but they’ll tell you whether the problem is in the fixture or the infrastructure.

Where DIY goes wrong: resetting a Toto on an uneven flange without a torque wrench cracks the vitreous china, and we’ve replaced three bowls in Boca Raton’s Hidden Lakes and Old Floresta neighborhoods in the past two years from exactly that. Post-tension slab drilling without locating cables risks structural failure and personal injury. The flange height relative to finished floor must be within 1/4 inch; too high and the seal leaks, too low and the bowl rocks until it cracks. We pull permits through Boca Raton Building Services and pass inspection the first time, which protects your resale disclosure.

Call (754) 254-8065 to schedule your free estimate. We’ll bring the Toto spec sheets, measure your rough-in, and put the number in writing before anyone picks up a tool.

FAQs

What to Expect When You Call

Grant Rowan and our team answer with a live person, 24/7. We’ll ask for your Toto model number, the rough-in measurement if you have it, and whether this is a new addition, an ADU, or a correction to existing work. You’ll receive a written, line-item quote before we schedule, a documented photo record during the visit, and a signed completion checklist before we leave. Measure twice, document everything, then build. That’s how we’ve kept 4,000-plus projects within a few percent of the agreed price since 2007.

Rowan Construction Group Boca Raton is an independent contractor and is not affiliated with Toto USA. We also stock and install KraftMaid cabinetry, Cambria countertops, and Silestone surfaces for full addition and ADU builds.

Written by Grant Rowan, Owner, Rowan Construction Group Boca Raton at Rowan Construction Group Boca Raton, serving Boca Raton and nearby areas.