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Toto Home Additions & ADU: The Miami Owner’s Guide
A Toto home addition or ADU in Miami typically runs $53,100 to $153,400, depending on square footage, foundation work, and whether you’re adding a full bath with Toto fixtures. We install and build additions that are Toto-ready from the rough-in stage through finish, so your Toto toilet, bidet seat, or tub integrates cleanly the first time. Most homeowners call us after discovering their existing Toto fixture no longer fits a new floor plan, or after a handyman “made it work” and left a slight leak behind the wall that nobody noticed for six months.
Which Toto Models This Applies To
We work with the full Toto residential lineup across Miami additions and ADUs, including the Drake, Drake II, Ultramax II, Nexus, Aquia, Legato, and the Washlet-integrated models like the Neorest. The compatibility gotcha most homeowners miss: Toto’s rough-in measurement isn’t always the standard 12 inches. Several Toto skirted models, including the Aquia and Nexus lines, use Toto’s UniFit adapter system, which gives you 10-inch, 12-inch, or 14-inch rough-in flexibility. That’s an advantage, but only if your plumber knows it exists before the drain pipe goes in. We stock the common UniFit adapters on the truck and plan drain placement around the exact model you choose, not the other way around.
OEM versus aftermarket matters more with Toto than with most brands. Toto’s fill valves, flappers, and flush towers are engineered to work with Toto’s 1.6 GPF or 1.28 GPF systems, and generic aftermarket flappers often seal poorly in Toto’s flush tower design, causing a slow, constant leak. We use OEM Toto parts for anything that touches water flow or the flush mechanism. For trim pieces and seat hardware, quality aftermarket equivalents work fine and cost 30 to 50 percent less, and we’ll tell you which is which before you spend a dollar.
Styles & brands we work with
Signs Your Toto Home Additions & ADU Is Failing
- Toilet rocks slightly when you sit down. This usually means the flange is cracked, the bolts loosened, or the floor underneath has softened from a slow leak. In Miami’s humidity, subfloor rot around a toilet can travel farther than you’d expect before it shows on the surface.
- Bidet seat trips the GFCI when heated water kicks on. The Washlet’s inline water heater draws real current, and an aging GFCI outlet or a slight internal short in the seat’s heating element will trip it. We check the outlet, the seat, and the dedicated circuit before throwing parts at it.
- Water runs for a few seconds every half hour, but no one flushed. This is almost always a worn flapper or, on Toto’s dual-flush tower models, a degrading flush tower gasket. It’s a silent water bill problem, and in Miami, where water rates run higher than the national average, it adds up fast.
- You smell sewer gas near a seldom-used guest bath in your addition. Toto’s water spot design keeps water in the bowl, but if the wax ring or UniFit adapter seal has failed, sewer gas seeps around the base. This is also a slow leak risk if the bowl doesn’t completely seal on the flange.
- New tile floor makes the old toilet sit too high. After a floor tile installation, the flange sits below the finished floor height, and a single wax ring no longer seals. We see this constantly in Miami ADUs where someone tiled over the original floor and reused the old wax. The fix is a flange extension or a double-thick wax, but guessing wrong means pulling the toilet twice.
See the difference
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After
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AfterReplacement Cost & What’s Included
A Toto-ready home addition in Miami runs $53,100 to $153,400, and the Toto-specific plumbing and fixture work inside that project adds roughly $2,400 to $8,900 depending on fixture count and whether you’re adding a Washlet with a dedicated circuit. For a standalone Toto bathroom addition within an existing ADU, budget $10,600 to $33,040. Every job gets a written price before we start. That number includes the permit, the rough-in, the Toto fixtures, the finish trim, and the final inspection. What it does not include is change orders you didn’t ask for.
Our parts-and-labor pricing on Toto replacements is straightforward: a Toto fill valve replacement runs $160 to $285 installed, a flush tower assembly replacement runs $180 to $320, a wax ring or UniFit re-seal runs $195 to $365, and a Washlet seat replacement, depending on model, runs $640 to $2,900 installed. We’ll tell you the exact line-item cost before any wrench turns.
DIY or Call Us?
You can safely check a few things yourself: confirm the model number stamped inside the tank lid, verify the rough-in measurement from the wall to the center of the drain bolts, and check whether your GFCI outlet is tripped on a Washlet. That’s useful information to have when you call. But if a Toto toilet has been rocking, or the floor feels soft around the base, or you’re adding a fixture to a new addition, call us. A mis-seated toilet in a new Miami ADU is a fast way to rot a subfloor and void your building permit’s plumbing inspection. Our technicians are background-checked, uniformed, and you’ll get the name and photo of who’s coming before they arrive. Call (850) 780-8123 and we’ll schedule the visit.
FAQs
A properly installed Toto toilet lasts 20 to 30 years in Miami, but the internal parts, especially the flapper or flush tower gasket, typically need replacement every 3 to 5 years because mineral content in South Florida water hardens the rubber sooner. A replacement flush tower gasket runs $180 to $320 installed. Call (850) 780-8123 for an exact quote.
Fill valves, flappers, and flush tower gaskets are repairable with OEM Toto parts, and in most cases that’s the right call. If the bowl itself is cracked or the finish is worn through, replacement is cheaper than repair. We’ll show you the failure and give you both prices before you decide.
A standard Toto toilet or bidet seat replacement takes 1 to 2 hours on site once the rough-in is confirmed. Full Toto-ready plumbing in a new ADU bathroom takes 2 to 4 days depending on drain location and whether a dedicated circuit is needed for a Washlet.
We stock common Toto OEM parts on our trucks across Miami, including UniFit adapters, fill valves, flush tower gaskets, and standard wax rings. Niche parts for Neorest or specialty Washlet models come from Toto suppliers within 2 to 3 business days. We also stock parts for KraftMaid cabinetry, Cambria surfaces, and Silestone counters so your addition gets finished without three different vendors. Call (850) 780-8123 to confirm availability for your model.
Tell me what you need done. I’ll tell you what it costs and when it’s finished, and I’ll mean both.
Mason Remodeling Co Miami is an independent service provider and is not affiliated with Toto. Toto, Washlet, Neorest, and UniFit are trademarks of their respective owners.
Written by Isaac Pruett, Owner, Mason Remodeling Co Miami at Mason Remodeling Co Miami, serving Miami and nearby areas.
