How Much Does It Cost to Add a Bathroom in 2025?

This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.

Budgeting is crucial when you plan a bathroom addition. On average, the cost to add a bathroom falls between $5,000 and $75,000, with most homeowners spending an average of $35,000. Expect a cost of $375 per square foot, depending on size, materials, and labor. A bathroom pro can give you an accurate estimate and handle the code work.

Bathroom Addition Cost Factors

Many factors impact your bathroom addition costs, including whether you’re adding onto your home or converting an existing room into a bathroom, as well as permits and labor rates for plumbing and electrical pros. Here are the cost breakdowns for these factors.

Build Type

Plan on spending $375 per square foot on the cost to add a bathroom, but the price changes if you convert an existing room instead of building a brand-new bump-out. Here’s the cost-per-square-foot breakdown for these two different types of builds.

Fixture Installation

Bathroom fixtures run a wide range of costs depending on the quality you choose. These are the average cost ranges of bathroom fixtures.

Permits

Building permits cost $50 to $2,000, depending on location and project scope. You’ll likely need one for electrical, framing, drywall, plumbing, and some finishes. Since requirements vary by area, it's important to check with your local code enforcement office. Permits are necessary if you're planning to:

• Alter the existing floor plan

• Make structural changes, such as adding doors or windows

• Install new ductwork or modify existing systems

• Relocate or install new electrical or plumbing fixtures

Labor

Labor makes up an average of 55% of the total budget. A plumber charges $45 to $200 per hour, depending on location, experience, and license level. Plumbing a new bathroom can cost $1,000 to $10,000, and prices climb the farther the space sits from existing lines. The farther away it is and the more complex it is, the more you’ll pay. It’s best to place your new bathroom near existing plumbing. Otherwise, the cost of running new lines to your bathroom can dominate your budget.

Bathroom plumbing rough-in costs $3,000 to $20,000, depending on the number of fixtures you want. Sometimes, that price includes final hookups as well as the rough-in, but it will require a second trip. After the rough-in, the plumber returns once floors, walls, and cabinets are in place to set fixtures and make final connections.

Cost by Bathroom Type

The type and size of bathroom you install will determine the final cost of your bathroom addition. Keep costs down by putting it near existing plumbing. Here are the costs associated with different bathroom types.

Master Bathroom

Adding a primary bathroom costs $22,000 to $90,000, depending on the fixtures and features you choose. Luxury additions add to the cost. For example, whirlpool tub installations run an average of $10,000.

Half Bath or Powder Room

Adding a half bathroom, also known as a powder room, costs between $4,000 and $12,000. This is a great option to enhance guests' convenience and reduce traffic in your main bathrooms without taking up much space.

Three-Quarter to Full Bath

A full bathroom costs between $10,000 and $50,000, and a three‐quarter bathroom costs between $6,000 and $22,000.

Cost to Add a Bathroom in an Existing Space

Transforming an existing space into a bathroom costs between $5,000 and $35,000, with most homeowners spending an average of $15,000. The final price depends on factors like the room's location, the finish quality you desire, and how close it is to existing plumbing.

Upstairs

Adding a bathroom upstairs can cost between $8,000 and $35,000. A key factor is whether there's existing plumbing on the second floor. If you're placing a bathroom where no plumbing currently exists, you'll need to install new lines, which can increase the cost.

Laundry Room

Turning your laundry room into a bathroom costs between $5,000 and $19,000. Since the plumbing is already in place, you can save a significant amount on installation costs. With only minor modifications needed, adding a half bath or powder room could be an affordable way to enhance your home's convenience.

Attic

Converting attic space into a bathroom costs $8,000 to $35,000, depending on the level of finishing required. Unfinished attics will cost more due to the need for installing insulation and drywall.

Garage

Installing a bathroom in your garage costs between $8,000 and $25,000. Garages offer flexibility in spacing and design, and because they often have easy access to electrical and plumbing connections, you can keep costs down. 

If the bathroom is primarily for utility purposes, standard finishes may suffice, making this an economical option. Walls that border a garage often bear loads, meaning you’ll need to install a header beam to carry the load when putting a door in.

Bedroom

Turning a bedroom into a bathroom costs anywhere from $15,000 to $50,000 on average. However, if you’re creating a master suite, you might pay $90,000 or more, depending on a few factors, including:

• Size of the space: More space means more flooring, tile, amenities, and remodeling expenses.

• Quality of finishes: Finishes greatly impact budgets. You can choose anything from builder-grade basics to high-end works of art.

• Distance from plumbing: The farther you are, the longer it will take to run lines.

Closet

Converting a closet into a bathroom can cost between $5,000 and $10,000, depending on the closet's size and its proximity to existing plumbing. Due to limited space, closet conversions focus on essential features, making them a practical option without the need for elaborate fixtures.

Existing Bathroom Split

Turning one bathroom into two costs $10,000 to $30,000 on average, which can be a good investment if you're creating a master suite or increasing the number of bathrooms to match the number of bedrooms.

DIY vs. Hiring a Bathroom Remodeler

Even if you’re handy, it’s wise to bring in a local bathroom remodeler for an addition of this size. A bathroom requires expertise in plumbing and electrical work, as well as installing fixtures, and a remodeling pro can manage these components to ensure that your new bathroom addition is built safely and to code.

Hire a trusted bathroom-remodeling pro to keep the work safe and code-compliant.

Does Adding a Bathroom Increase Home Value?

An extra bathroom boosts day-to-day convenience and can raise your home’s resale value. Homeowners often see a 55% return on investment (ROI) for a bathroom addition when selling their home. Beyond the financial return, an extra bathroom improves daily convenience and can lead to energy and water savings with modern, efficient fixtures.

How HomeAdvisor Gets Its Cost Data

No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. After a project is complete, we survey real customers about the costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.