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Kohler Home Additions & ADU: The San Francisco Owner’s Guide
If you’re planning a Kohler-finished home addition or ADU in San Francisco, a full project typically runs $53,100 – $153,400 depending on square footage, foundation work, and the level of Kohler fixture and finish specification. We install Kohler fixtures, valves, and trim across additions, garage conversions, and ADU builds throughout the city, and we carry the most common Kohler replacement and rough-in parts on the truck so a failed valve or missing escutcheon doesn’t stall the final inspection. Most owners discover a parts need at the worst possible moment: the plumber sets the valve body, the tile goes up, and then the trim kit arrives with a missing cartridge cap or the wrong shower arm length. That’s the call we answer with the part in hand, not a three-week order window.
Elmstead Remodeling San Francisco is an independent remodeling contractor and is not affiliated with Kohler. We specify and install Kohler product because the valves, cartridges, and trim are serviceable years later, and because the company keeps exploded parts diagrams available for every series we touch.
Which Kohler Models This Applies To
This page covers Kohler rough-in valves, trim kits, cartridges, shower arms, tub spouts, and drain assemblies used in additions and ADUs, not a single model family. The compatibility detail that matters most in San Francisco is the difference between Kohler’s Rite-Temp and Purist/Thermostatic valve platforms. Rite-Temp pressure-balancing valves (K-304, K-8304, and the universal K-8304-K-NA with the slip-fit spud) take a different cartridge and trim set than the Purist thermostatic valves (K-2971, K-2973), and the trim kits do not swap between them. If you’re matching an existing valve, look inside the wall at the brass body, not at the handle style: the model number is stamped on the valve body itself, and that’s the number that determines which cartridge and trim kit fit. For OEM versus aftermarket, we default to genuine Kohler cartridges for anything behind tile. An aftermarket O-ring kit or a generic shower arm is fine for exposed parts, but a cartridge that fails behind a newly tiled ADU shower wall is a $2,000 tile repair to save $40. Not a trade we recommend.
Styles & brands we work with
Signs Your Kohler Home Additions & ADU Is Failing
- Water temperature swings when a toilet flushes or a washing machine cycles. This is the pressure-balancing spool inside the Rite-Temp cartridge sticking, common in older San Francisco homes where sediment from aging supply lines works into the valve body.
- A handle that turns past its stop or spins without changing temperature. The cartridge stem has worn or the limit stop has cracked. Seen often in ADUs with hard water, which describes a lot of the Richmond District and Sunset District supply.
- Drips from the tub spout after the water is off. That’s not necessarily the valve; it’s often the diverter seal in a Kohler spout, but on newer thermostatic systems it can be a cartridge bypass issue. We’ll diagnose it before quoting the repair.
- The trim plate sits off the wall or rattles. Usually a missing backer plate or a flange that wasn’t set to the right depth before tile. Kohler specifies a rough-in depth range for every valve; outside that range, the trim will never sit flush.
- Low flow from the showerhead that a new head doesn’t fix. The flow restrictor or the integrated volume control in the valve is clogged, common in ADUs fed from older galvanized supply lines common in the Mission and Noe Valley.
Replacement Cost & What’s Included
In San Francisco, a straightforward Kohler cartridge replacement on an existing valve runs $295 – $825 including the part, and a full valve-and-trim swap with access repair lands between $1,500 and $3,500 depending on whether we’re opening tile or drywall. For new construction additions and ADUs, Kohler fixtures and rough-in plumbing are part of the overall $53,100 – $153,400 project scope, and we itemize the exact Kohler part numbers on the written price we hand you before any work starts so there’s no “allowance” game at the fixture showroom. That written price includes the Kohler parts, labor, the shoe covers and drop cloths on your floors, and a photo of the clean-up before the crew leaves. The 365-Day Done Right Promise applies to the entire project: if the Kohler valve or trim we installed isn’t done right after the job is complete, we make it right.
See the difference
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After
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AfterDIY or Call Us?
You can safely inspect a few things without shutting off water or opening a wall: check whether the model number on the trim plate matches what you ordered, confirm the shower arm length, and test whether the handle turns smoothly. What we’d rather you not do is open a Kohler pressure-balancing or thermostatic valve body yourself. The cartridge retention nut on Rite-Temp valves is under spring pressure, the supply stops are often frozen in older San Francisco plumbing, and a slip with a pipe wrench on the brass body turns a $300 cartridge job into a full valve replacement behind fresh tile. If you’ve already opened the wall and found a cracked cartridge or a stripped stem, call us at (831) 480-4497 and describe what you’re seeing. We’ll bring the right Kohler part and the right rough-in depth tool to set it correctly the first time.
FAQs
A genuine Kohler Rite-Temp cartridge typically lasts 8 – 15 years in San Francisco, though hard water and older galvanized supply lines in the Sunset, Richmond, and Excelsior can shorten that to 5 – 8 years. Thermostatic Purist cartridges run longer, often 15 – 20 years, because they have fewer moving seals exposed to sediment.
Not reliably. Kohler cartridges are sealed units, and the internal pressure-balancing spool isn’t serviceable without damaging the housing. We replace the cartridge with a genuine Kohler part rather than rebuilding it. Call (831) 480-4497 for an exact quote on your valve series; estimates are free.
Most cartridge replacements take 45 to 90 minutes on site. A full valve and trim swap with tile or drywall access runs half a day to a full day depending on what’s behind the wall. We’ll tell you the schedule before the crew arrives, and we set quiet hours so the work fits your family’s day.
We stock the most common Kohler Rite-Temp cartridges, shower arms, tub spouts, and trim screws on the truck. For less common Purist or thermostatic parts, we source same-week from our local Kohler supply partners in San Francisco so the project isn’t waiting on a cross-country shipment. For Kohler parts on an addition or ADU we’re building, we order the full rough-in set before the rough inspection so the parts are in your house, not on backorder.
Other Brands We Stock
Alongside Kohler, we regularly install and service fixtures and finishes from KraftMaid, Cambria, and Silestone across kitchen and bath additions. If your ADU project mixes Kohler plumbing with Cambria tops and KraftMaid cabinets, we’ll coordinate all of it under one written price.
Written by Graham Stein, Owner, Elmstead Remodeling San Francisco at Elmstead Remodeling San Francisco, serving San Francisco and nearby areas.
