How Much Does It Cost To Add A Bathroom?

The cost to add a bathroom will largely depend on whether you are adding a bathroom to an existing space or adding an addition.

The average cost of adding a bathroom to an existing space is $15,000, whereas the average cost of adding a new bathroom addition is $30,000.

The total range for adding a bathroom is between $5,000 and $100,000.

You can use our Bathroom Remodel Calculator to estimate the cost of adding a new bathroom.

Because the cost varies so significantly there are many choices you can make to lower or increase your total project cost.

All of the important choices for adding a bathroom are described in detail in the guide below to help you choose the right price point for your bathroom.

Existing Space New Addition
Average Cost $15,000 $30,000
Low Cost $5,000 $15,000
High Cost $35,000 $100,000


Cost of Adding a Second Toilet

Adding an additional toilet costs between $1,500 and $4,000, depending on the toilet type. To install a new toilet, a waste pipe must be installed, which may require cutting or drilling into the floor below. The toilet should tie into an existing stack line and must have a cold water line. Adding a toilet costs $150 to $3,000, plus the cost of the plumbing and toilet. This can be a major project, depending on where you install the toilet.

Talk to local pros to get quotes for your bathroom addition project

Going Upstairs with a Half Bathroom Addition

If your planned half bathroom project is on the second floor of your home, the average cost you should expect is between $8,000 and $35,000. Before you decide to add a half bathroom upstairs, make yourself aware of some of the obstacles you may face.

Plumbing and Electrical

The first consideration is where do you tap into the water lines and the drain lines?  If there is no existing plumbing upstairs, just getting plumbing to the second floor poses problems. Where can your contractor tap into existing lines with the least trouble?  Will you need to pull down ceilings on the first floor or open walls to run the plumbing and electrical?

Just getting water and sewer connections to your second floor may cost as much as the bathroom. In some instances, the construction costs just to run the water and sewer lines can be between $6,000 and $15,000. This cost is above and beyond the cost of adding the half bathroom.

What’s Above the New Bathroom?

You must also consider what is above the new bathroom on the second floor. Remember, adding a bathroom also requires adding a vent to the room for the drain lines. Routing a vent on a home with three stories might present problems.

Two-story homes generally have an attic. The attic space above the half bathroom addition makes installing a vent through the roof relatively easy. However, if there is a third story above the new half bathroom space, finding a way to route the drain vent to the roof can get tricky. You can easily spend $1,000 to $6,000 routing vent pipes for a second-story half bathroom.

A Basement Half Bathroom

Homes with basements are great opportunities for half bathroom additions. Many families bundle the addition of a half bathroom into a basement finishing project. In most instances, you can expect the cost of a basement half bathroom addition to run $8,000 to $15,000. Adding a half bathroom to a basement has both advantages and disadvantages.

The Upside of a Basement Half Bathroom Addition

Generally, plumbing is not as much of an issue in a basement as in other parts of a home. If the basement is unfinished, drains, water lines, and electrical are usually easily accessible. Even if the basement is already finished, making plumbing and electrical connections is easy.

The cost of adding a basement half bathroom where a rough-in drain already exists can save even more money. An existing rough-in floor drain lowers the cost even more. In most instances, if water and sewer connections are already present, a basement half bathroom installation runs between $8,000 and $12,000.

The Problems with Basement Half Bathroom Additions

Adding a half bathroom to a basement is not without its possible problems. If the basement is already finished, expect additional costs for remodeling the space after the half bathroom is complete.

One major problem can be the location and depth of the main sewer line tap. If the main sewer line serving your home is shallower than your basement floor, you may have to install a sewer lift pump. This can add additional costs to your project. Expect the overall cost, in this case, to go over the $15,000 mark.

Do you need a window for a bathroom in a garage?

Bathrooms need a window that provides at least one and a half square feet of flow space. Even if the window in the bathroom is open, steam will still float around inside. Therefore, you can also install an exhaust fan in your garage bathroom to manage ventilation.

Cost Of Drywall For Building A Bathroom

You will likely need to add at least one wall to build your bathroom. The main determinant of the price of drywall is the square footage you add, because all drywall is roughly equal in quality.

Expect to spend $2.75-$4.20 per square foot to install drywall. In a 100 sq.ft. room the total cost to hang drywall is $600 – 800.

Should I Hire a Contractor or Manage the Half Bathroom Project Myself?

Our recommendation for a project as involved as a half bathroom addition is to hire a licensed and bonded contractor to handle the project. A reputable contractor brings several advantages to the project.

  • The contractor is responsible for the project. You don’t need to be on the job site all the time to oversee the work.
  • A licensed and bonded contractor has the necessary insurance to protect you and the other sub-contractors on the job site.
  • Licensed and bonded contractors understand the permitting and inspection process. Usually, good contractors have a working relationship with the building inspectors if problems do arise.
  • Your contractor should give you an estimate for the job before they begin the work. This allows you to budget and plan for the project in advance.

Does Adding a Bathroom Add Value?

In most instances, yes, adding another bathroom to your home can add value. Bathroom additions have an average ROI of 54%. This means that whatever you spend on the addition increases your house’s value by roughly 54% of the total cost. This varies by the area and home type. For example, if you have a three or four-bedroom home with one bathroom, adding a second bathroom can make your home much easier to sell and adds more ROI. However, a home that already has two bathrooms with two bedrooms may not get as big of a return.

Should I add a half bath?

Adding a half bathroom into the home’s design can be a great investment. On average, adding a half bath to your home can increase the value 10.5 percent. The addition can also improve your lifestyle, giving your family and guests the extra personal space they need for quick cleanups and toilet breaks.

The Cost of Building a New Space for Your Bathroom Addition

Rebecca Rollins Interiors

Here's the bad news about building an addition for your bathroom: It's expensive. HomeAdvisor estimates that the average cost of a new bathroom addition is $35,000, but that it can cost anywhere from $20,000 to $90,000. But before you give up on your addition entirely, there's good news, too: You won't have to figure out how to awkwardly reconfigure your home around your new bathroom, plus the added square footage gives a major boost to your home's resale value.

If you want to make the most of your bathroom addition, consider using the renovation to add on another space, like a bedroom or multi-purpose room.

Cost To Build A Bathroom

The cost to build a new bathroom addition to your house will cost around $22,000 on average, or $47,000 to $87,000 using high-end materials. Professional plumbers and electricians will chart $85 to $120 per hour and permits for a new home addition cost between $200 and $500.

Cost To Plumb A Bathroom

Cost To Plumb A Bathroom

At $85–$120 per hour for plumbing labor, plumbing your new bathroom can run from $610–$1,180 for labor only using mid-grade items—not high-end components, which cost more to install. You’ll need hot and cold water for both the sink and shower/tub and a water line and sewage pipe for the toilet. If you have a basement or crawlspace, it will cost less than a concrete slab that needs to be cut through.

Electrical Work for a Bathroom Addition

Electricians charge from $85–$120 an hour (labor only) to work on a home addition, depending on where you live. You’ll need new electrical work for

  • outlets,
  • fans, and
  • adequate lighting.

You’ll need to install GFI (ground fault interrupter) outlets because of the proximity to water, and you have to add a vent to the exterior if there is no bathroom window. If you add showers and toilets with tech components, you’ll need to wire the bathroom for those as well.

Permits and Legal Regulations

You’ll need to check in with your local building department to find out about necessary permits. Building codes often include minimum bathroom dimensions; the smallest two-fixture bathroom is 5’ x 4’. Some HOAs have regulations about home additions. If you have a general contractor overseeing this job, he or she will know what you need to proceed legally, but in general, you’ll need permits for:

  • Adding additional space to the home and building new walls
  • Any electrical work – all wiring must be up to code
  • Any other plumbing and waste ducts and pipes brought to a new location

Having permits ensures all work is done to meet the building codes in your county. It will be inspected once completed, so you can rest assured that everything is as it should be. Costs vary depending on where you live, but permits run in the region of $200 to $500.

Parting Words

That was all about how much does it cost to add a half bathroom. Hopefully, our piece was of use to you.

Just draw up a nice budget plan for making your new half bathroom. Don’t forget to use our cost calculator. It’ll help you immensely.

That’s it for today. Good luck with your renovation!

New Half Bathroom Cost Breakdown

Building a half bathroom depends on more than one or two factors. Planning, permits, material cost, installation, labor fees, finishing, there’s a lot to think about. If you wish to build a new bath, you must consider all these factors.

It’s important to make a proper budget before you start with your renovation project. Every renovation project requires cost planning. Just like how you’d plan the cost for building a tiny house in advance. 

If you calculate them all together, you can make a proper budget for yourself. After all, from luxury to mid-range to typical, half-baths need budget planning. For better understanding, we’ve included the cost breakdown of an ideal-sized half bathroom. 

This is the total cost-breakdown for an ideal size or 35 sq. ft. half-bathroom-


To add a new half-bath in your home you’d need proper planning. You can make the Interior design by taking a consultant’s help. This will cost you around $150-$500. After you get the design, you can hire a contractor. 

The contractor’s work includes plumbing, electrical, HVAC, and other labor costs as well. So, if you hire a contractor you won’t have to worry about other works individually. The cost range for hiring a contractor is $300-$400 per day.


To build a new bathroom you’d need a building permit. To get the permit you’d have to contact your local building department. They will tell you all the necessary procedures that you have to follow. For adding a half bathroom, the permit cost will range from $200-$500.

Working with a general contractor will help a lot in this case. Contractors are aware of the legal procedures for building permits. Generally, you’d need a permit for the following addition to your home-

  • Building walls or adding space to your home (applies to adding a new bathroom)
  • Adding electrical lines 
  • Adding plumbing lines

Some of the states have different requirements mentioned on the permit. Once the building is completed, it’ll be checked by the local building inspection team. That’s why you must assure that the work is done as it should be. 


Raw materials are a big part of the total cost of building a bathroom. It might even exceed the cost of moving a garage. When talking about a half-bathroom, you wouldn’t need many components like a master bath. But if you have more space, you can always add different materials up to your choice.

It’s important to know the market price of the components that you’re gonna use. That way, your budget plan would be more detailed and precise. We’ve made a list of the cost for materials based on their price range. 

So, get your list ready right now-


Making a half-bathroom doesn’t cost a lot if you compare the average cost. But the cost will definitely get higher if you plan on using luxury materials. A lot of people want to build luxury half-baths even if the space is small. 

This is the price range for luxury bathroom materials-

MaterialsLuxury Price Range 
Bathroom Vanity$3,000-$5,500
Faucets $1,500-$2,500
Door & Windows$1,000-$3,000
Total $21,000-$40,500

Note that not all of the materials are needed to be used for half-bathrooms. Because there’s a space limitation in half baths. Anyhow, the total price ranges from $21,000 – $40,500. With this price range, you can even cover the cost of remodeling a bathroom.


Even mid-range materials can give your bathroom a luxurious look. If your budget is not good enough for luxurious half-baths, choose from here. The total price ranges from $11,000 – $22,600.

MaterialsMid-Range Price
Bathroom Vanity$2,000-$3,500
Door & Windows$500-$2,000
Total $11,000-$22,600


This pricing list is appropriate for a tight budget plan. The total price range is $1,630 – $10,800. Within this price range, you can easily build a good enough half bath. 

Here’s the list for the regular material’s price range-

MaterialsTypical Price Range 
Bathroom Fan$50-$300
Bathroom Vanity$300-$3,000
Faucets $250-$1,000
Door & Windows$200-$1,800
Total $1,630-$10,800


The plumbing cost for a half bathroom ranges between $1,000 to $10,000. The cost range depends on the layout of the bathroom. The distance between the designated place and the existing plumbing line also matters. The cost increases with the distance.

The plumber fee ranges from $85-$120 per hour. The cost range varies depending on the type of plumbing work. For installing high-end and complex plumbing routes the cost is higher.

Electrical work

Doing electrical work for a half bathroom costs about $1,000 to $5,000. You’d need new electrical components to install in your bathroom. 

Here’s a price list of them-

Cost FactorsPrice Range
Electrical panel & wiring installation$600-$1,200
Breaker panel upgrade$500-$1,500
GFCI Outlet $40-$60 (each)
Switch $150-$200 (each)

Apart from these costs, you’d also have to pay the electrician fee. Electricians charge from $85-$120 per hour. 

Fixture & Accessory Installation

Just buying fixtures and accessories isn’t enough. You have to calculate the installation fee as well. The installation cost for luxury items is slightly higher than the regular installation cost. 

The table below shows the installation price range for both regular and luxury materials. Here’s the price range for installing fixtures and bathroom accessories-

FixturesInstallation Cost
Toilet $122-$228
Faucets $150-$300
Vanity $500-$2,000
Cabinets $400-$1,500


Flooring a half bathroom will cost you around $1,500 – $4,500. The price range depends on what material flooring you’re choosing for the bathroom. It’s advisable to use waterproof flooring.

Here are some recommended choices for flooring-

Types Of MaterialPrice Range (per sq. ft.)
Linoleum $5-$10
Luxury Vinyl Plank$5-$10
Ceramic/ Porcelain$5-$15
Stone $5-$12

Tile installers will cost you $5-$10 per sq. ft.


The current code of the building requires installing exhaust fans in every bathroom window. Building a bathroom window can cost you $500 to $900. An exhaust fan costs around $350 to $400 including the installation cost. 

There are many good-quality exhaust fans available in the market. These are our picks based on their longevity and productivity-

Product 1
Product 2

It’s pretty important to add a proper ventilation system to your bathroom. Otherwise, mold and mildew can affect the walls and floor very quickly.

Drywall & Painting

Installing drywall will cost you around $1,000 – $1,500. It cost $2 per sq. ft. to install drywall. You’d also have to count the cost of painting. Painting a half bathroom costs around $150-$500. Wall painters work for $40-$75 per hour.

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. 

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

Request a Free Material Sample Kit:

Kit includes:

  • 4 inch stone resin material samples
  • Both Matte and Glossy finishes
  • Choice of White, Black or Gray
  • Bathtub templates to help you plan your space
  • High resolution product catalog


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