What is the Average Cost to Add a Bathroom?

Adding a bathroom seems like a simple project, and this is why so many people are surprised at the average cost to add a bathroom to their home. It doesn’t matter if you’re going to build an extension and add a bathroom or convert an existing space, this can be an expensive project. Converting an existing space is much less expensive than adding a new addition, and it typically starts around $5,000 to convert a space. 

If you’re going the other direction and you want to add a new addition to your home, you can easily pay upwards of $50,000 to complete the project by the time you get through all of the plumbing and building requirements. If you want to create a spa-like bathroom that is around 100-square feet, you have to be prepared to spend around or over $75,000. This means that you have to watch your budget very carefully. However, the bright side is that you can recover up to 70% of this initial investment if you decide to sell your home. 

Factoring in the average cost to add a bathroom to your home allows you to make your life easier. You won’t blow your budget while making your life easier. A second or third bathroom gives everyone in your home options, and it allows more residents to use them at one time. Your average cost to build a bathroom will vary, and you can get them in all sizes and shapes from spa-quality master suites to tiny half baths. 

Since the price varies depending on location, whether or not you want to convert a space or add a new one, type of bathroom, plumbing, electricity, flooring, sink, toilet installation costs, and more. We’re going to go over all of these components and more to give you an excellent idea on the average cost to add a bathroom as it applies to your situation. This way, you can budget for it and boost your home’s functionality and value all in one go. 

1 Bathroom Remodel
Your average cost to add a bathroom will vary, but the least you can expect to spend is around $5,000 to install a small half bath in an existing space. 
Tub by Brian / CC BY 2.0

Adding a New Addition vs Converting an Existing Space Costs

Depending on how you build your new bathroom and the location, the average cost to add a bathroom comes with a huge price range. Converting a space you already have in your own home is the more cost-effective choice, but this may not be feasible for some people. Additionally, every area in your home will have different building costs attached to it, so this is something to consider when you’re trying to figure out the average cost to add a bathroom. 

For example, adding a bathroom into your basement can cost just as much as it would to add a bathroom addition onto your home. Converting an unused bedroom or closet into a bathroom will cost less. If you have a finished interior that you reroute plumbing to and tile, the average cost to add a bathroom to this space is just as much as you’d pay for a full remodel. On average, it’s around $18,000 to tear out the bathroom to the studs and remodel it. 

Adding a whole new addition for your bathroom means you have additional costs to think about like a crawl space or foundation extension, interior finishing, framing, and exterior finishing. On average, your new addition can cost upwards of $250 per square foot for a simple bathroom. For a luxury space, the average cost to add a bathroom jumps to $450 to $600 per square foot. You’ll also have to factor in costs for things like electric, plumbing, and performing routine finish work for your bathroom. This can increase your installation price to around $50,000 and up. 

How Location Influences the Project Price

The location where you want your new bathroom can influence the average cost to add a bathroom. There are several common areas to add a new bathroom in your home. You can add it in a basement as part of the finishing process, in an attic, in a bedroom space or existing closet, or as an extension of your home in conjunction with a new addition or alone. 

Keep in mind that the further your new bathroom is from the existing plumbing, the more this will drive up your average cost to add a bathroom. It’s more intensive and it will take longer to drive your project costs up. You’ll have to run lines to the bathroom from your main plumbing, and it can be harder to access the space. 

Average Cost to Add a Bathroom to an Existing Space

Most homeowners will pay an average of $15,000 to add a bathroom to an existing space once they get all of the plumbing and remodeling finished. This means roughly $125 to $250 per square foot for an average bathroom. Luxury features will cost more. You also have to remember that you’re not adding to your home’s square footage, so you’re losing this space for something else. 

2 Bathroom Demo
You can reduce your labor expenses for this project if you do the demolition yourself. However, it’s a good idea to hire professionals to do the electrical and plumbing.
Bathroom Remodel – Demolition Phase by Bradjward / CC BY-NC 2.0

Average Cost to Add a Bathroom to a Basement

The average cost to add a bathroom to the basement will cost between $8,000 and $15,000 to complete the project. If your space already has a rough drain in place, it can save you between $500 and $1,000. Newer homes usually have these drains that are right near the main drain line, and they’re popular in basement laundry rooms

Additionally, it’s usually more cost-effective to install a bathroom in an unfinished basement versus a finished one because you won’t have to pay for demo work, and you can easily pull from any existing plumbing that runs to your main floors. If you’re going to do a complete remodel of the basement, you’ll spend between $12,000 and $30,000. The bathroom will take up 30% to 50% of the basement finishing costs. 

The plumbing costs for a basement bathroom addition will cost between $1,500 and $4000, and the price will fluctuate depending on the number of fixtures you want. This price can include a rough in and the final hookups. A plumber will have to come and install the rough in before waiting on the floors, cabinets, and walls. Then, they’ll come back and install the fixtures and connect them. Other costs include the hourly rates of your plumber that can run between $45 and $200, faucet installation costs, and drain line replacement costs that can cost between $225 and $1,200. 

Cost to Transform a Bedroom into a Bathroom

The average cost to add a bathroom in this space will range between $15,000 to $50,000. If you want to create a master suite, the sots can easily jump up to $90,000. The size of the space is one large factor, and more space means installing more flooring, amenities, tile, and stacking up the remodeling expenses. 

The finish quality also counts, and finishes can easily blow your budget. You can have high-end pieces or choose to save money by installing builder-grade basics. The distance from the plumbing and drains also factors in. The farther your new bathroom is from the drains or plumbing, the more it’ll cost to run lines, and the more you’ll pay out in labor costs.  

Cost to Add an Attic Bathroom

If you want to convert your attic space to a bathroom, you can expect to spend between $8,000 and $35,000. The level of finishing that exists in the attic will be the biggest factor in figuring out your average cost to add a bathroom to this space. If you have a finished attic that you want to enclose and install fixtures and plumbing, it’ll cost between $8,000 and $15,000 to complete. 

For anyone who has an unfinished attic or who wants to install higher-end features, the average cost to add a bathroom has a cost range of $15,000 to $35,000 and up. This budget will include the bath itself as well as the insulation. The budget should also include modest finishing of the rest of the space, paint, and drywall. 

Cost to Add a Bathroom to a Closet

Depending on the size of the existing closet and how far it is away from the available drains and plumbing, the average cost to add a bathroom to an existing closet ranges from $5,000 to $20,000. A half bath is your most cost-effective choice, and the price will go up if you want a quarter or full bath installed. A lot of closet to bathroom conversions are more basic, and they usually don’t contain things like tiled showers, expensive vanities, or cabinetry. Since this is a smaller area, your space is at a premium. 

3 Small Bathroom
Since space is such a premium in smaller bathrooms, you have to get creative to ensure everything fits and flows nicely without cluttering up your space.
Fixtures Closeup by Paul Schultz / CC BY 2.0

Cost to Add a Bathroom to Your Garage

Building a garage allows you to add a bathroom, but you can also renovate an existing garage to add anything from a small bathroom to a master suite. Generally speaking, the average cost to add a bathroom to a garage will cost between $8,000 and $25,000. Garages usually have more options for design and space, depending on where your plumbing and electricity comes from. Many times, electric and plumbing opens into the garage, and you can save money by adding a builder grade room instead of something luxurious. 

If you plan to take your garage and expand a bedroom into a larger master suite, the spending range goes up. It starts at $15,000 and goes up to $50,000. Any wall that borders a garage is a load-bearing wall, and this means that it’s required for you to install a header beam that will help carry the load when you put a door in. There is also a broad range of finishing costs available. 

Cost to Add a Half Bath

Maybe you only need a half bath added to your existing space. If so, the average cost to add a bathroom ranges between $5,000 to $15,000. If you have to add space to create your half bath, the price goes up to $10,000 and $30,000. A half bath is a toilet and a sink without a tub or shower. It’ll add half of the value to your home’s price than a full bath, but it’s essential for homes that have a single bathroom. 

Cost to Switch a Laundry Room to a Bathroom

The average cost to add a bathroom starts at $5,000, but it can go up to around $12,000 easily. However, using an existing laundry room can work to save you money on plumbing because it’s already in this space. There are drains for the washer to drain the water away when you finish with your laundry. This means that this space only requires minor modifications. If you decide to do a half bath or a budget bath with a powder room, it could only cost around $5,000. 

Cost to Install an Upstairs Bathroom

Maybe you have an old bedroom upstairs that used to belong to your kids that you don’t need anymore, you could consider remodeling it to turn it into a bathroom. The average cost to add a bathroom in this space has a broad price range that starts at $8,000 and goes up to $35,000. One of the biggest costs you want to consider is if the upstairs area has any plumbing running to it. You’ll have to run a host of new lines if you’re going to install the bathroom upstairs where there are no drains. 

Cost to Convert One Bathroom to Two Bathrooms

Switching an existing bathroom into dual spaces can range between $10,000 and $30,000. If you want to upgrade the features in your bathroom while you’re at it and install finishes, the cost can start to rise. This is especially true if you plan on upgrading in both rooms instead of reusing what you have. 

There are a few instances where it’s a good idea to spend a little more and bring the average cost to add a bathroom up. One instance is when you’re trying to create a new area for a master suite with a bathroom. If you want to increase the number of bathrooms to match your bedrooms before you sell, this can increase your home’s overall value. 

Bathroom Type and Pricing

The average cost to add a bathroom will fluctuate depending on the type of bathroom you want to install. For example, choosing to add a small half bath will cost around 50% less than it would if you wanted to install a full bathroom, unless you went for luxury. 

  • Half Bath – The average cost to add a bathroom of this type is around $12,000 for 12-square feet. You only need a sink, toilet, and a mirror. It can include a linen closet or cabinet for storage, but you have a very small space to work with. 
  • Three-Quarters Bath – The average cost to add a bathroom that is around 36-square feet is $35,000. You get slightly more space, and it usually has enough room to accommodate a stall shower, mirror, sink, and a toilet. You could also have a closet or cabinet for storage space. 
  • Full Bath – For 48-square feet, the cost to add a bathroom in this style is right around $41,000. You’ll add a mirror, sink, toilet, and a separate shower and tub or a tub/shower combination. It has space for several cabinets or storage shelves, and you can put in a linen closet without making it cramped. 

4 Bathroom Type
There are three main bathroom types you can choose from, and your budget will play a large role in the one you end up with because the prices are broad.
570 Wake Robin Bathroom Upstairs by John Coley / CC BY 2.0

Important Factors That Influence Your Total Project Price

There are several things you want to consider when you’re trying to figure out the average cost to add a bathroom. Depending on which ones you want to include in your project, they can play a significant role in how well you stay in your budget. 


If you choose to install a linen tower or a vanity instead of a linen closet, you’re going to incur additional costs. You could save money by having a pedestal or wall-hung sink. On average, vanity cabinets will start around $200 for an 18-inch sink base cabinet that is very basic and simple. The cabinetry can go up to thousands of dollars if you want a 72-inch double vanity with linen towers and drawers. For a bathroom vanity that measures 48-inches, you’ll pay around $2,000. 


If you plan to convert an existing area in your home, this will save you in electrical costs. Adding a new addition to your home means that there is much more electrical work, including wiring the space and upgrading your existing electrical panel. You’ll need at least one GFCI outlet in your bathroom, and you’ll also have lights and an exhaust fan. Most electricians will charge you between $65 and $85 per hour, and it can take anywhere from a few hours to a few days to get your electricity wired and running. 

Faucet and Sink Installation

The next biggest part of your bathroom design is the sink. You can choose from wall-hung designs, as part of a console system, freestanding, or install it into a vanity. On average, you’ll spend around $400 for your sink installation. For the faucet, this will add to your average cost to add a bathroom by around $200. Faucets come in single hole styles and four or eight-inch spreads. 


You can cover your bathroom floor in a huge range of materials, but most bathrooms use tile. Tile is water-resistant, and it can also be slip-resistant. Porcelain is extremely common in bathrooms of all sizes because it’s non-porous, and this means that it won’t absorb water as you step in and out of the shower or bath. The cost to install your bathroom flooring is usually around $900. 


Since you have to bring in several different contractors to install your bathroom, labor costs are a big component of the average cost to add a bathroom. For basic framing, you’ll want to find a carpenter, and they charge around $70 per hour. A plumber will charge between $45 and $65 to install your new fixtures and pipes. An electrician will wire your space for $65 to $85 per hour, and a tile installer for your flooring runs around $4.00 per square foot. 

If you need a general contractor to help you with a whole new build, they charge around $125 a square foot for their time. A bathroom designer to ensure the space comes together well is between $50 and $200 per hour. These are average price ranges, and they can fluctuate depending on how involved your build is and the location in your home. 

Plumbing and Pipes

General plumbing and pipe installation can also drive your average cost to add a bathroom to the upper limits of your budget. Generally, any bathroom will need two or more water sources, and you’ll also need waste pipes installed. For all of the plumbing, fixtures, and pipes, you’ll spend around $13,500. 

5 Plumber
Hiring professionals and labor costs are going to make up a large portion of the average cost to add a bathroom, especially if you have a more elaborate project planned out.
Plumber by Ben Baligad / CC BY 2.0

Shower and Tub

Unless you’re planning on putting in a half bath, you’ll need a shower, tub, or a tub/shower combination installed. Almost all full baths come with an alcove tub installed that will allow it to double as a shower. You can also install a single shower stall, a stand-alone tub, or a tub right next to your shower stall. The average cost to add an alcove tub to your space is right around $2,500. A shower installation ranges from $950 to $2,000. If you want a shower door, you’ll add $800 to the average cost to add a bathroom budget. 


Toilets are a very important part of any bathroom project, and they come in a lot of sizes and shapes. You can choose wall-hung or floor-mounted designs, and they come in two pieces or as a single piece. Toilets have different flush and float systems that come in different heights. If you don’t include plumbing or supplies, the average cost to install a toilet is around $350. 

Additional Bathroom Features and Prices

There are features that can improve your bathroom’s aesthetic and function, but they can increase your average cost to add a bathroom. So, it’s a good idea to wait on these pieces if you’re not sure you have the budget for them. 

    • Fan – Local codes usually require you to have a fan to help lower the humidity levels and circulate the air. They cost between $350 and $400 for the parts and labor. 
  • Mirror – Mirrors are another important aspect of your bathroom, especially if you install them above your vanity or sink. You could get mirrors with medicine cabinets, lights, or magnifying shaving mirrors that range between $120 and $150. 
  •  Radiant Flooring Radiant flooring is heated flooring that can make the bathroom comfortable. You can install them as an electric floor mat or as pipes, and the costs range between $6,000 and $14,000. 
  • Sauna or Steam Shower – Steam showers are excellent options instead of a performance shower or tub. Converting your traditional shower to a steam shower or sauna costs around $6,000.

Permit Costs

Generally speaking, permits can add between $50 and $2,000 to your average cost to add a bathroom, depending on the scope of your project and your location. You’ll need permits for framing, electrical, plumbing, drywall, and some finishes. You’ll want to check with your local code enforcement office before you start. If you plan on altering your existing floor plan, install new or reroute ductwork, make structural changes like adding windows or doors, or install or relocate plumbing or electrical fixtures, you’ll need permits. 

Where to Find Bathroom Remodelers and Contractors 

If you are looking for a professional bathroom contractor near you, here is a resource we recommend:

Frequently Asked Questions

6 Questions 1
Taking on a bathroom remodel or installation uses a lot of different trades and features that can all add up quickly. Getting a solid estimate beforehand will help you stay in your budget.
P1020251.JPG by Brad Cerenzia / CC BY 2.0

1. What is the most cost-effective way to add a bathroom to your home?

The most cost-effective way to control your average cost to add a bathroom is to put it in an existing space. It’ll already have electrical, plumbing, and HVAC installed. The laundry room and basement are the two cheapest areas in your home. 

2. Can a toilet go anywhere in your home?

Technically, you can put a toilet anywhere in your home. However, you’ll have to run a waste pipe from it, and you’ll need a stackline for every toilet at a minimum. This can limit your options. 

3. Is it possible to add a bathroom to a house with a concrete slab foundation?

Yes, you can add a bathroom to your home if it has a concrete slab foundation. However, this can cost more because your contractor will have to think outside of the box to run new sewer and water lines. This can also make the install go on longer. 

4. What is the average cost to add a bathroom if it’s a master suite with a bedroom?

If you want to add a full master suite onto your existing home, this can be an expensive project. You’ll pay between $21,500 and $65,000 to complete it, and this is the national average. 

Bottom Line

The average cost to add a bathroom to your home varies depending on a large variety of factors. While it’s cheaper to add a bathroom to your existing space, this may not be feasible with smaller houses. Now that you know everything that goes into figuring out the average cost to add a bathroom, you can apply it to your situation and see if this project is in your budget. If it is, this can boost your home’s value and help you get a nice return on your investment when you sell. 

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