Half Bath to Full Bath Conversion Cost in New Berlin, WI
Adding a shower to a half bath costs $8,044 on average, according to This Old House, with $2,778 of that going to labor. A simple job that sets a prefabricated shower stall close to the existing plumbing costs less. A job that borrows space from a closet, reroutes pipes or adds custom tile costs more.
Published 2026-11-05 · 8 min read · 1,702 words
In New Berlin, the age of the house shapes the job. Census figures show 53% of the city's 17,577 homes were built before 1980, and about a third were built in the 1960s and 1970s. This Old House notes that converting an older half bath can require extra demolition or upgrades to bring everything up to code. This guide covers the costs, the space a shower needs under Wisconsin's plumbing code, and the permits the City of New Berlin requires.
Half Bath to Full Bath Cost by Component
This Old House breaks its $8,044 average into the main pieces of the job.
| Component | Average material | Average labor | Average total |
|---|---|---|---|
| Plumbing installation | $2,804 | $2,741 | $5,545 |
| Backsplash | $951 | $1,095 | $2,046 |
| Shower door | $1,462 | $138 | $1,600 |
| Shower liner | $1,304 | $237 | $1,541 |
| Shower pan | $959 | $193 | $1,151 |
| Tile floor | $83 | $517 | $600 |
| Shower base | $338 | $165 | $503 |
| Electrical work | $202 | $254 | $456 |
| Shower drain | $41 | $105 | $146 |
| Shower head | $69 | $33 | $102 |
These are averages for each piece, not a list to add up. A project uses a shower base or a tiled pan, and a liner or tiled walls, not all of them. The plumbing line is the one that moves most, because it depends on how far the new shower sits from the existing drain and water lines.
Line Item Costs for a Prefabricated Shower
Homewyse's national figures show what the core pieces of a simple conversion cost when they are priced one by one.
| Line item | Homewyse national cost (May 2026) |
|---|---|
| Fiberglass shower stall, set at existing rough-ins | $1,457 to $1,715 |
| Pressure-balanced shower faucet and head | $639 to $1,020 |
| Shower drain connected to the main drain | $412 to $497 |
| New water line with shutoff, up to 30 feet | $689 to $843 |
| Bathroom exhaust fan, wired and vented | $343 to $889 |
| Glass shower door | $916 to $1,297 |
| Move an existing plumbing line | $935 to $1,138 per run |
Remodel - T&JThe stall, faucet, drain, water line and fan add up to about $3,500 to $5,000. That covers the shower itself, not the framing, wall finishes, flooring, electrical work or permits around it, which is why finished projects land closer to the This Old House average.
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Wisconsin's plumbing code requires a shower drain of at least 2 inches in diameter, while a sink drain only has to be 1 1/4 inches. A new shower usually needs its own larger drain line rather than a tie-in to the sink's.
Will a Shower Fit in Your Half Bath?
- Room size. This Old House says you generally need at least 30 square feet to fit a shower comfortably. Many powder rooms are smaller, so the extra space often comes from a closet, a hallway or the room next door.
- The shower itself. Wisconsin's plumbing code requires a shower to have at least 900 square inches of floor and room for a 30 inch circle, or room for a 25 inch circle with at least 1,300 square inches. That space has to hold up to 70 inches above the drain.
- The toilet. The code also requires at least 15 inches from the center of the toilet to any side wall, vanity or other obstruction, and 24 inches of clear space in front of it.
- Smart layouts. Corner and neo-angle stalls, sliding doors, wall-mounted sinks and recessed shelves save floor space in a tight room.
Plumbing, Waterproofing and the Exhaust Fan
- Water lines. A shower needs hot and cold supply lines. Tying them into the nearby sink or toilet lines keeps labor and cost down.
- Drain and vent. The new drain must slope properly to the house sewer line and be vented so sewer gas stays out of the room.
- Waterproofing. A tiled, site-built shower floor needs a waterproof safing layer under the whole floor, carried at least 6 inches above the curb, with the corners protected to a height of 6 feet. A one-piece fiberglass stall avoids most of that work.
- Exhaust fan. Wisconsin's Uniform Dwelling Code requires any room with a toilet, tub or shower to have exhaust ventilation of 50 cubic feet per minute when it runs intermittently, or 20 when it runs continuously. This Old House adds that the fan should vent outside, not into an attic. Our bathroom exhaust fan cost guide covers the options.
- Electrical. Outlets need ground-fault protection, and a light over the shower should be rated for damp locations.
If the half bath is in the basement, the new shower drain may sit below the sewer line, which can mean cutting the concrete floor or adding a pump. Our basement bathroom addition cost guide covers that case.
Permits for a Half Bath Conversion in New Berlin
- Plumbing permit. The City of New Berlin's permit table lists plumbing fixtures, including tubs, toilets, showers and sinks, as needing a plumbing permit.
- Building and electrical permits. The same table lists interior additions and alterations as needing building and electrical permits, with a plumbing permit depending on the work.
- Where to apply. Permits are handled by the Department of Community Development on the second floor of City Hall at 3805 S. Casper Drive, and a building permit review can take up to 10 business days.
Our guide to bathroom plumbing permits in Wisconsin explains who can do the plumbing and what the inspections cover.
Is Adding a Shower to a Half Bath Worth It?
This Old House says the upgrade can return up to 35% of its cost in resale value, and that it makes the most sense in a home with only one shower, a growing family, frequent guests or plans to age in place. The case rests mostly on everyday use. A second shower cuts the morning wait for a busy household, and the work typically takes 1 to 3 weeks.
Questions to Ask Before You Compare Bids
Is there room for a 30 inch circle in the shower
and 24 inches of clear space in front of the toilet?
Will the shower get its own 2 inch drain,
and how will it be vented?
Prefabricated stall or tiled shower,
and how will it be waterproofed?
Is an exhaust fan that vents outside included?
Which permits will you pull,
and are the fees in the price?
What happens if the old pipes behind the wall need replacing?
Getting a Half Bath Conversion Estimate
A free in-home consultation measures the room, finds the nearest drain and water lines, and prices the conversion in writing. If you are weighing a conversion against a new bathroom elsewhere, our guide to the cost to add a bathroom compares the options, and our New Berlin bathroom remodel cost guide shows full remodel budgets.
T&J is a father-and-son team that has worked in Wisconsin since 1989. John is your single point of contact from the first call through the final walkthrough, Telli is on site running the work, and T&J gives a written 2-year warranty. Homeowners in New Berlin and across Waukesha County can see our bathroom remodeling in New Berlin page and our bathroom remodeling services, or request a free in-home estimate.
Frequently asked questions
How much does it cost to turn a half bath into a full bath in New Berlin?
This Old House puts the average cost of adding a shower to a half bath at $8,044, with $2,778 in labor. Homewyse's line items for a simple prefabricated shower add up to about $3,500 to $5,000 before walls, flooring, electrical work and permits.
How much space do you need to add a shower to a half bath?
This Old House says about 30 square feet. Wisconsin's plumbing code requires the shower itself to have at least 900 square inches of floor and room for a 30 inch circle, plus 24 inches of clear space in front of the toilet.
Do I need a permit to convert a half bath to a full bath in New Berlin?
Yes. The City of New Berlin requires a plumbing permit for new fixtures such as showers, and building and electrical permits for interior alterations.
Can you add a shower to any half bath?
Not always. The room needs enough space, a drain that can slope to the sewer line, hot and cold water, and ventilation. A half bath below the sewer line may also need a pump.
Does adding a shower to a half bath increase home value?
It can. This Old House says the project can return up to 35% of its cost in resale value, and it helps most in a home with only one shower.
Does a bathroom with a shower need an exhaust fan in Wisconsin?
Yes. Wisconsin's Uniform Dwelling Code requires exhaust ventilation of 50 cubic feet per minute running intermittently, or 20 running continuously, in any room with a toilet, tub or shower.
How long does it take to convert a half bath to a full bath?
This Old House says the project typically takes 1 to 3 weeks, depending on the plumbing and how much the layout changes.
Pricing is based on our own recent projects. Written by John (PM, 14 yrs) and reviewed by Telli, who has been remodeling in Wisconsin since 1989. Published 2026-11-05.
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