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Home & Garden Remodeling & Interior Cost guide

How Much Does It Cost to Add a Bathroom? (Price Guide)

Updated  3 sources

Typical cost to add a bathroom

$21,000 – $49,000

Adding a bathroom usually costs $21,000 – $49,000, depending on size, location in the house, and finish level.

Putting a new bathroom into a house is mostly a plumbing project. Fixtures and tile are visible, but the larger expense is usually running water supply, drains, and a vent where none existed. That is why the location of the new bathroom changes the price as much as its size.

Below, costs are split three ways: by bathroom type, by where the bathroom goes, and by project size. Each answers a different planning question.

Cost to Add a Bathroom by Type

A half bath holds a toilet and sink. A three-quarter bath adds a shower, and a full bath adds a tub. The more fixtures, the more plumbing and finishing work.

Cost to add a bathroom by type

Item Typical range Relative price range
Half bathroom / powder room $5,000 – $15,000
Three-quarter bathroom $10,000 – $22,000
Full bathroom $15,000 – $35,000
Primary bathroom $25,000 – $100,000

Source: Fixr: Bathroom addition cost

Where Is the Bathroom Going?

Putting a bathroom near existing pipes is the cheapest route. Moving farther from the main drain and supply lines adds labor and may mean cutting into floors or ceilings.

Cost to add a bathroom by location

Item Typical range Relative price range
Closet conversion $5,000 – $15,000
Attic $8,000 – $35,000
Basement $10,000 – $50,000
New addition $20,000 – $50,000

Sources: Fixr: Bathroom addition cost; Block Renovation: Cost to add a bathroom

A few practical notes on each location:

  • Closet conversion: Small and efficient when a closet backs onto a bathroom or kitchen wall. A shower or tub rarely fits.
  • Attic: Needs adequate ceiling height and floor support, and the drain has to reach the stack below.
  • Basement: Below the main sewer line, a drain may need a pump, which adds equipment and a place for something to fail. Moisture control also matters.
  • New addition: Gives the most layout freedom but needs foundation, framing, and roofing along with the plumbing.

Cost per Square Foot

Converting space you already have is cheaper than building new, because the walls, floor, and roof are already there.

Cost per square foot

Item Typical range Relative price range
Converting existing space $200 – $250/sq ft
Building a new addition $400 – $550/sq ft

Source: Fixr: Bathroom addition cost

Average Project Price by Bathroom Size

Larger rooms mean more tile, more fixtures, and more labor, though the price rises more slowly than the square footage because the plumbing is the fixed core of the job.

Average project price by bathroom size

Item Price
Half bathroom (25 sq ft) $18,000
Full bathroom (50 sq ft) $21,000
Primary bathroom (100 sq ft) $28,000

Source: This Old House: Cost to add a bathroom

What Changes the Cost of a New Bathroom

  • Distance to existing plumbing: Shorter runs cost less.
  • Fixture quality: A basic toilet and vanity cost far less than a freestanding tub or custom shower.
  • Tile and finish choices: Floor and wall materials can double the finishing budget.
  • Ventilation and electrical: A new exhaust fan, lighting, and outlets that meet code are part of the job.
  • Structural changes: Cutting a floor joist or moving a wall adds engineering and carpentry.
  • Labor rates: Plumbers and tile setters price differently by region.

Why Estimates Vary

The three guides compared below do not use the same assumptions. Some blend all bathroom types into one average, others lean toward smaller conversions, and a few include the cost of framing a new space. Compare the type, size, and location, not just the headline number.

Estimates by source

Item Typical range Average Relative price range
This Old House $21,000 – $49,000—
Fixr $10,000 – $35,000$20,000
Block Renovation $5,000 – $35,000—

Sources: This Old House: Cost to add a bathroom; Fixr: Bathroom addition cost; Block Renovation: Cost to add a bathroom

Hiring and Permits

Adding a bathroom nearly always requires a plumbing permit, and often electrical and building permits as well. Your local building department can tell you which apply. Hire a licensed plumber for the supply, drain, and vent work. Mistakes inside walls are expensive to uncover later, and unpermitted plumbing can complicate a future sale or insurance claim.

When you compare bids, ask whether tile, fixtures, and the exhaust fan are included or treated as allowances you choose later. Ask also who handles drywall and paint after the plumber finishes, since patching can end up as a separate line.

Does a New Bathroom Pay Off?

A second or third bathroom is useful in a house with several bedrooms, and buyers tend to look for it. Whether you recover the cost depends on your market and on the quality of the work. A real estate agent in your area can tell you how much value a bathroom adds locally.

Frequently asked questions

How much does it cost to add a bathroom?

Most guides give $21,000 – $49,000, per This Old House.

How much does a half bath cost to add?

A half bathroom or powder room runs $5,000 – $15,000. It is the least expensive type because it skips the shower or tub.

What is the cheapest place to add a bathroom?

A closet conversion is listed at $5,000 – $15,000, lower than an attic or basement. Proximity to existing plumbing makes the biggest difference.

How much does it cost to add a bathroom per square foot?

Converting existing space runs $200 – $250/sq ft. Building a new addition is $400 – $550/sq ft.

How much does a full bathroom cost to add?

A full bathroom is listed at $15,000 – $35,000. A 50 sq ft bathroom averages $21,000 in one guide.