Cost To Add a Bathroom

How much does it cost to add a bathroom?

Adding another bathroom to your home can make life a lot easier. An additional bathroom provides options to the house’s occupants and can accommodate more residents at one time. New bathrooms come in all shapes and sizes, from tiny half baths to large, spa-quality master bathrooms.

The average homeowner adding a 6×8-foot bathroom in a new space can expect to spend around $47,000 for the complete job.

Conversion of existing space vs new addition to the house

Costs for a bathroom addition range tremendously depending on where the new bathroom is located and how it is built. Converting an existing space within your home can cost less than building a new addition. However, not every area in your home will have the same build costs.

Adding a bathroom to an unfinished basement will cost nearly as much as adding a bathroom addition to the house. Converting an unused bedroom or closet into a bathroom, however, will cost less. A finished interior space that is being tiled and plumbing rerouted will cost the same as a full bathroom remodel, meaning a tear out to the studs and remodel, around $18,000 on average. However, if you build a new addition, you will have additional costs, such as a foundation or crawl space extension, framing, and interior and exterior finishing. New additions cost around $124 per square foot for the addition itself. There are additional costs for adding plumbing, electric, and the finish work for the bathroom, resulting in a final price of around $47,000.


The location for the new bathroom can influence your final cost. Common areas to add a bathroom include existing closet or bedroom space, an attic, a basement as part of the finishing, or an extension to your home either alone or in conjunction with a larger addition, such as a new master bedroom.

The farther the bathroom is from already finished areas of your home, the higher the costs will go, the longer the project will take, and the more intensive the process.

Type of bathroom

The type of bathroom you install also dictates some of the costs of the addition. Adding a small half bathroom, for example, costs less than a full bath:

Bathroom type Description Cost

Half bathroom

Small space

Toilet, sink, and mirror are all that are necessary

May include a cabinet or linen closet for storage

$12,000/12 sq.ft.

¾ bathroom

Medium space

Toilet, sink, mirror, and stall shower

May include cabinets or a closet for storage

Able to fit in smaller spaces than a full bath, but with more utility than a half bath

$35,000/36 sq.ft.

Full bathroom

Medium to large space

Toilet, sink, mirror, and either a tub/shower combination or separate tub and shower

May include various types of cabinetry and shelving for storage as well as a potential linen closet

$47,000/48 sq.ft.

Pipe installation

A large part of the costs of the bathroom addition is for the pipe installation. Bathrooms, by definition, require two or more sources of water to be installed plus waste pipes. Adding plumbing to your bathroom addition will cost around $13,600 for the pipes and fixtures.


If you are converting an already finished space, then the electrical work will be minimal. However, if you are adding a new space to your home, expect there to be more involved wiring, including the possible need for a panel upgrade. Bathrooms need to have at least one GFCI outlet installed as well as a fan and lights. Electricians charge between $65 and $85 per hour, and you can expect anywhere from a few hours to a few days of work, depending on the type of addition.

Shower/tub installation

Unless your addition is a half bathroom, you will need to have a bathtub, shower, or tub/shower combination installed. Most full baths have an alcove tub installed that doubles as a shower. However, it is possible to install a single stall shower, a tub next to a stall shower, or a stand-alone tub. In most cases, an alcove tub installation costs around $2,500, while a shower stall installation ranges anywhere from $930 to $2,000. Adding a shower door costs an additional $800.

Toilet installation

Toilets are an integral part of any bathroom and come in many shapes and sizes. They can be floor-mounted or wall-hung and are available as a single piece or two separate pieces. They also have different float and flush systems and come in varying heights. The average toilet installation is around $350, not including the supplies and plumbing.

Sink/faucet installation

The sink is the next biggest component in the bathroom design. Sinks in the bathroom can be wall-hung, freestanding, part of a console system, or installed on a vanity. The sink installation costs around $400 on average. Faucets have an additional cost of around $200 and come in 4-inch spreads, 8-inch spreads, or single hole styles.

Flooring installation

The bathroom floor can be covered in a variety of materials, but tile is the most common. It is important to choose a bathroom floor that is both slip-resistant and water-resistant. Porcelain is one of the most common choices because it is non-porous. Installation of a bathroom floor costs around $900.

Bathroom cabinets

If you choose to have a vanity installed or a linen tower instead of a linen closet, you will have additional costs than if you opt for a wall-hung or pedestal sink. Vanity cabinets start at around $200 on average for a very simple 18-inch sink base cabinet and can reach thousands of dollars for custom 72-inch double vanities with drawers and linen towers. The average cost for a bathroom vanity measuring 48 inches is around $2,000.


Several professionals are involved in the installation of a new bathroom addition. You need to hire a carpenter ($70/hour) for the basic framing, a plumber ($45-$65/hour) for the pipes and fixture installation, an electrician ($65-$85/hour), and a tile installer ($4/square foot). You may also need to engage the services of a general contractor ($125/square foot) and a bathroom designer ($50-$200/hour), depending on where the addition is located and how involved the process is.

Enhancement and improvement costs


Mirrors are also an integral part of the bathroom, typically installed above the sink or vanity. They may include magnifying shaving mirrors, lights, or a medicine cabinet and cost around $120 to $150 on average.

Bathroom fan

Bathroom fans are often required by code and help circulate air and lower the amount of humidity in the room. They cost about $350 to $400.

Radiant flooring

Radiant heat flooring can make your bathroom floor more comfortable. It may be installed as pipes or an electric mat and goes beneath your tile floor. Typical costs are around $6,000 to $14,000.

Steam Shower/sauna

Adding steam to your shower is a great alternative to performance showers or tubs and may provide positive health benefits. Converting your shower to steam adds another $6,000 on average.

Towel warmers

Towel warmers help keep towels dry while warming them for your use. They help stop the growth of mold or bacteria on wet towels and make them feel more comfortable as well. Towel warmers have a wide range of costs, with the average being around $2,000.

Whirlpool tub

A jetted or whirlpool tub is a great addition as well, giving you a relaxing massage and warmth. They can be found in sizes that fit an alcove shower or may be stand-alone additions. They start at $2,000 per tub and may climb as high as $20,000.

Additional considerations and costs

  • If you have a basement or crawl space, your bathroom addition will be easier and less costly than if you have a slab foundation 1.
  • Visit NKBA to get the most up-to-date bathroom size guidelines to ensure that you have the space necessary for your fixture placements to pass code.
  • It is common to find things inside attics, crawlspaces, and basements that you were not aware of, such as mold, asbestos 2, or water leaks. You may want to check for these issues before you begin so that you can plan for the additional work or remediation as needed.
  • If you have pets, there are some features you may want to consider adding for their benefit, such as a handheld showerhead ($20$50) or easy-to-clean porcelain tile.
  • Low-flow faucets and fixtures help you save money on water costs each year. Most of these cost the same as their standard competitors, so there are no additional costs.
  • Consider using Universal Design in your bathroom to both accommodate ADA guidelines as well as aging in place and to open your home up to a broader market at resale time.
  • If you do not have enough space for a full bath, consider adding a three-quarters bathroom, which consists of a toilet, sink, and stall shower rather than a half bath, which is only a toilet and sink.
  • You will need to have a permit to add a bathroom to your home, and it must pass code. Each state has its own plumbing requirements and codes, so be sure to check before you begin to see what may be required by law.
  • Adding a bathroom to your home can increase its value. It can also improve the function of your home and make it easier for multiple residents to get ready for their day at the same time.
  • If you have a small bathroom that already exists, you may want to consider remodeling it instead of adding a new bathroom. Remodels can sometimes increase size, which can also raise value and increase functionality.


  • How much does an average bathroom addition cost?

The average bathroom addition costs around $47,000 for a new space bathroom addition.

  • How much does it cost to add a bathroom to a basement?

Bathroom additions in a basement cost around $15,000 to $20,000, depending on the finishing and location.​

  • How much does it cost to put a bathroom in the garage?

If the garage is attached to the home, it will cost between $15,000 and $20,000.

  • Do you need a permit to add a bathroom?

Yes, you need to pull a permit and have the bathroom inspected. Laws vary by state, so check with local authorities.

  • Can you put a toilet anywhere in your house?

Technically yes, but for best results, you need to run a waste pipe and stackline for each toilet location, which can limit your options. ​

  • Do you need planning permission for an outside toilet?

Yes, because toilets need to hook up to either sewer or septic tanks, they require a permit.​

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