Why tub-to-shower conversions are the most common San Diego bath project

Most 1960s-1990s San Diego tract homes were built with an alcove tub on the wet wall and a separate showerhead on a riser pipe. Half the homeowners using that bath in 2026 never take a bath. The tub is a tripping hazard, a kid’s bath, a dog wash, and 60 inches of wall that could be a walk-in shower. A tub-to-shower conversion is the most common bath project we see across the county, from 1972 Mira Mesa ranches to 1988 Scripps Ranch two-stories to 1994 Rancho Bernardo single-stories.

A clean conversion solves four problems: it removes the stepping-over tub wall for aging-in-place, it opens the bathroom by 8-15 square feet of usable floor, it gives a true walk-in shower with a low or zero threshold, and it does it for a fraction of the cost of a full bathroom gut. The work is the same trades (demo, plumbing, tile, glass, paint) but a smaller scope, and the project usually lands in the $14,000-$26,000 range for a typical San Diego conversion.

This is a walk through what a conversion actually involves, what stays and what goes, what the project costs, and what to ask the crew before signing.

What stays and what goes in a conversion

What stays: the wet wall framing (usually), the existing shutoff valves, the toilet, the vanity, the mirror, the exhaust fan, most of the electrical, and the bathroom door. About 70% of the bathroom is untouched in a typical conversion.

What goes: the alcove tub, the tile surround on the wet wall, the glass shower door or curtain rod, the waste-and-overflow drain, and the tub spout. The tub filler valve either gets replaced with a shower-only valve or stays capped if the homeowner wants the option to add a tub filler back later.

What sometimes changes: the drain location. If the new shower is a curbless walk-in with a linear drain at the back wall, the original tub drain at the front of the wet zone has to be relocated. The drain move is the most common surprise in a conversion, and it costs $1,200-$2,500 in plumbing.

The right starting point for any conversion is a free in-home consult where a plumber and a tile setter look at the existing wet zone, the framing, the drain, and the subfloor. The tub-to-shower conversion page has the line items for a typical project, and the walk-in shower page has the shower-only line items.

The four project types, ranked

1. Like-for-like conversion: tile surround replaced, tub removed, new shower pan and glass. This is the most common and the most affordable. The wet wall framing stays, the drain stays in the same location, the shower valve is replaced, and a new pan, new tile, and a new glass enclosure go in. A typical San Diego like-for-like conversion runs $9,000-$16,000.

2. Curbless conversion: pan lowered to the subfloor, linear drain at the back wall, zero-threshold entry. This is the accessibility-first conversion and the right answer for aging-in-place. The work is heavier (the subfloor has to be lowered or the floor built up to the pan), the drain has to move, and the glass usually has to be a fixed panel. A curbless conversion runs $13,000-$22,000.

3. Expanded conversion: wet wall pushed out 18-30 inches, larger shower footprint. This is the right answer when the bathroom is large enough to give the shower more floor space. It usually means moving one or two studs, re-routing a vent stack, and retiling the entire wet wall. An expanded conversion runs $15,000-$26,000.

4. Conversion plus full bath refresh: new vanity, new toilet, new flooring, new lighting, new shower. This is the conversion that becomes a full bath remodel in disguise. It is the right answer when the homeowner was going to remodel the bath in the next 3-5 years anyway, and it is more efficient to do it all at once. A conversion plus refresh runs $22,000-$40,000.

For most households, the curbless conversion is the right answer. The low threshold is safer, the open glass makes the bath feel bigger, and the linear drain reads as a design moment. The aging in place bathroom angle is on the walk-in tub page for households that need more accessibility than a curbless shower.

The plumbing decisions that matter

Three plumbing decisions define how a conversion feels and how it lasts.

1. The valve. A pressure-balancing valve is the code-required minimum, and it costs $120-$300 for the rough and the trim. A thermostatic valve is the upgrade that holds temperature steady when someone flushes a toilet or starts the dishwasher, and it costs $350-$900. For a San Diego conversion that may need to serve aging parents, a thermostatic valve is the right call.

2. The drain location. A standard 60-inch alcove tub has a left or right drain at the front of the tub. A conversion that keeps the same drain location is the cheapest path. A curbless conversion with a linear drain at the back wall has to move the drain 30-40 inches. The drain move is a $1,200-$2,500 line item in the plumbing scope.

3. The showerhead height and trim. A standard 72-inch showerhead is the code minimum. Most San Diego conversions end up at 78-80 inches for the showerhead, with a hand shower on a 30-inch slide bar for shorter household members. The slide bar is $80-$200 over a fixed showerhead, and it is worth the upgrade for any household with kids, a partner of different height, or mobility concerns.

The bathroom plumbing page has the rough-in and repipe line items, including drain moves and valve upgrades.

Tile and glass choices for a conversion

Tile. Most San Diego conversions retile the wet wall and the new shower floor. Porcelain wall tile in 12x24 or 16x32 inches is the standard and runs $8-$22 per square foot installed. Porcelain mosaic floor tile in 2x2 inches follows the slope of the pan without diagonal cuts and runs $12-$30 per square foot installed. Marble and natural stone are the wrong answer for the shower floor in a conversion, for the same reasons as a full shower remodel.

Glass. A semi-frameless sliding door runs $900-$1,800 and is the most common conversion enclosure. A heavy glass frameless enclosure runs $1,800-$4,500 and is the right call for a curbless conversion with a fixed panel. A fixed panel with no door runs $1,200-$2,800 and is the most accessible option for aging-in-place households.

The frameless glass shower line items are on the shower remodel page.

The cost breakdown for a typical San Diego conversion

A typical 60-inch alcove tub conversion in a San Diego tract home runs $14,000-$22,000. The line items look like this:

  • Design consult and layout: $500-$1,500
  • Demo of the tub, surround, and glass: $900-$2,000
  • Plumbing rough-in and valve: $1,800-$3,500
  • Drain move (if applicable): $1,200-$2,500
  • Schluter foam pan and curb: $400-$900
  • Waterproof membrane: $400-$900
  • Shower wall tile (porcelain, 50-80 sq ft): $1,200-$3,000
  • Shower floor tile (mosaic, 10-15 sq ft): $350-$700
  • Frameless or semi-frameless glass: $900-$3,000
  • Showerhead, hand shower, and trim: $250-$700
  • Paint, trim, and accessories: $400-$900
  • Permits: $300-$800

For most projects, the tile and the glass are the line items that move the budget. A 60-square-foot wet wall in mid-range porcelain with a semi-frameless glass enclosure lands in the mid-range. A 90-square-foot expanded conversion in bookmatched marble with a heavy glass enclosure climbs to the high end.

How to read a conversion quote

Three things separate a clean conversion quote from a corner-cut one:

  • Is the plumbing line a real line item with a valve specification, a drain move, and a fixture count? Or is it a single line that says “plumbing” with one number?
  • Is the waterproofing method called out? Schluter Kerdi, vinyl pan liner, or “redguard and tile.” The first two are code-compliant. The third is a corner cut.
  • Is the glass enclosure line showing panel thickness, hardware finish, and door type? Or is it “shower door” with one number?

If the quote lumps everything under “tub to shower” with one big number, demand a scope-of-work attachment before signing.

What to ask a conversion contractor

Three questions separate a tub-to-shower specialist from a generalist:

  • Have you done conversions in pre-1990 San Diego tract homes? The framing, the cast iron drain, and the subfloor in a 1972 Mira Mesa ranch are different from a 2005 Carlsbad new-build. The right crew has seen both.
  • Will you lower the subfloor for a curbless pan, or build up to a low-threshold pan? Both work; the choice depends on the floor framing and the homeowners’ preference. The honest answer depends on the home.
  • What is your lead time on a custom frameless glass enclosure? A 3-6 week lead time is normal. A 1-week promise is a red flag.

A good crew will not flinch at any of these questions. For the full bath scope that often pairs with a conversion, the full bathroom remodel page has the line items.

Call (858) 925-5546 to set up a free in-home consult. We measure the existing wet zone, check the framing and the drain, and tell you whether a like-for-like, a curbless, or an expanded conversion is the right call, and what the project actually costs.