How Much Does It Cost to Add a Half Bathroom? – Upgraded Home

How Much Does It Cost to Add a Half Bathroom? – Upgraded Home

Bathroom Addition Cost by Project Range


48 sq.ft. full bathroom conversion in an existing space with no new plumbing lines or modifications

Average Cost

48 sq.ft. full bathroom in a new space addition

High $60,000 100 sq.ft. master bathroom addition in a new space


Areas in your home that you can add a half bathroom

An important consideration when installing a new bathroom is where to place it. The beauty of a half bath is that it is much smaller than a traditional bathroom, giving you a greater deal of flexibility.

Here are some common areas in your home where you can add a half bath. A half bathroom adds a great deal of versatility to your home. Depending on where you install a half bath


A half bath is a great addition to a basement home office or child playroom. A half bath installed in the basement provides a more conveniently located bathroom out of the usual foot traffic. Also, the average cost to add a basement is around $10-15,000.

However, if you add the basement under an existing

However, if you add the basement under an existing bathroom, you can save anywhere between $1-2,000 in plumbing expenses. The only drawback to a basement half bath would be the ventilation and sewage-ejector system of your home.

Ensure that this system is properly routed through your home so that your wastewater can effectively travel up and out of your basement area to the proper channels. 


A closet bath provides a great choice as it remodels a small storage space and repurposes it. This cuts back on installation costs as you are adding to an existing space. Additionally, closets are conveniently placed in many homes, providing a natural recess to install a bath.

Keep in mind that the average cost to install a closet bath is anywhere from $5-15,000. Depending on the size of the existing closet and proper ventilation, it will be necessary, especially given the smaller space. 

Under a Staircase 

Similar to closet space, the storage area under a staircase is another good choice for a half bath as it repurposes an existing space. Many staircases have an empty space that many homes use for storage or a pantry, which makes it a logical area for a small bathroom.

Before installing in this area, ensure that space is around 25 square feet with a minimum height of 5 ft to keep with local building codes.

Additionally, ensure that proper ventilation can reach this bathroom through either a window or fan. The average cost for a stair installation starts around $3,000. 

Convert Laundry Room to a Half Bathroom

A laundry room can also provide a great location for a half bath. Many laundry rooms tend to have a large amount of space available, with existing plumbing already installed.

With plumbing costs lowered and the laundry room’s location typically out of the way of heavy foot traffic in your home, a laundry bathroom is a logical place to install a bathroom. The laundry room bathroom’s average cost would be anywhere from $5-12,000 depending on size and materials.  


A popular location, the long hallway in many homes provides a great deal of space for a bathroom to be installed. Windows can easily be added to this location, providing great ventilation compared to other areas.

The hallway also provides a convenient location that allows guests to enter and exit discreetly when using the bathroom. Depending on the location and materials, a hallway bathroom will run anywhere between $5-15,000.

A half bathroom provides your home with a great value-increasing your home’s price while offering a very versatile bathroom for you and your guests. But before you install one, remember to be cost-effective. Consider your existing water lines, drains, and electrical circuits to determine the best location for this bathroom.

Lastly, remember to strike a balance between luxury and budget so you can find the right look for your bathroom without breaking the bank. 

Can you remodel a bathroom for $5000?

On average, you can start remodeling a bathroom with only $2,500 and go up to $23,000. If your budget is $5,000, you can easily carry out the remodel. But, you may have to settle for necessary materials and even put in some effort yourself to complete the work.

How To Save Money On Adding A Half Bathroom?

As you can see, adding a new bath is not cheap at all. If you’re not careful it can take your bank balance to a poor state. That’s why you’d need to think of ways to reduce the extra cost. But the question is where can I reduce my cost?

Here we’ve gathered some tips for reducing the overall cost of adding a half-bath.


You can reduce a lot of the extra cost if you’ve a DIY mindset. Start with doing the demolition on your own. Clear out the area where you plan to build your bathroom. Don’t wait to pay the labor fee for this. You can do this yourself. 

But make sure you aren’t hurting your home’s structure. Otherwise, it may bring more trouble than ease.

Paint On Your Own

Painting is the easiest and fun job out there. You only need to be a little cautious. Otherwise, the job is super easy. Spending money on hiring a painter is not necessary if you’ve a tight budget. 

Simply take a pair of gloves, your paint, and a paint roller. Now, paint all the walls yourself and show your creativity. Even if you make a few mistakes it can be forgiven.

Tile The Floor/Wall On Your Own

Tiling the bathroom floor or wall isn’t as hard as it seems. All you need is some little guidance for it. You can take suggestions from a professional or someone who’s done it before. 

With a little practice, you can even master this art. Tiling by yourself will save you a lot of money.

So, how is your budget plan going? Hopefully, now you’ve got an idea of the factors you need to count on.

Additional Considerations and Costs

  • Guidelines. Visit NKBA to get the most up-to-date bathroom size guidelines to ensure you have the necessary space for your fixture placements to pass code. This should be done in the project design phase.
  • Inspection. It is common to find things inside attics, crawlspaces, and basements that you were unaware of, such as mold, asbestos 2, or water leaks. You may want to check for these issues before you begin to plan for additional work or remediation.
  • Pets. 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.
  • Universal Design. Consider using Universal Design in your bathroom to accommodate ADA guidelines and make aging in place easier. Doing so may also open your home up to a broader market at resale time.
  • Permit. You must have a permit to add a bathroom to your home, and it must pass code. Each state has plumbing requirements and codes, so check before you begin to see what may be required by law.
  • Added value. Adding a bathroom to your home can increase its value. It can also improve your home’s function and make it easier for multiple residents to get ready for their day at the same time.
  • Space. Make sure you consider the space’s size when adding a new bathroom. Not every space is large enough to fit everything. While small spaces can often become half baths, full bathrooms need considerably more room to be comfortable.

Cost Of Adding A Half Bathroom For Different Sizes

The cost of building a new bathroom depends on many factors. But it mostly depends on its size. 

Now, you might not want to add the ideal size half bathroom. Because there are actually lots of size options available. That’s why we’ve also calculated some common half-bathroom sizes per sq. ft. and the cost for adding it. 

See the table below to get a clear idea of it-

Size Average Cost For Existing PlaceAverage Cost For Building In a New Place
18 sq. ft.$3,600-$4,500$7,200-$10,800
21 sq. ft.$4,200-$5,250$8,400-$12,600
25 sq. ft.$5,000-$6,250$10,000-$15,000
28 sq. ft.$5,600-$7,000$11,200-$16,800
32 sq. ft.$6,400-$8,000$12,800-$19,200
35 sq. ft.$7,000-$8,750$14,000-$21,000
40 sq. ft.$8,000-$10,000$16,000-$24,000

Converting a Half Bath to a Full Bath

What if you want to convert that downstairs half bath to a full-sized one? According to HomeAdvisor, this can cost you anywhere between $5,000–$25,000. This range of costs depends on if you're using existing space, if there are difficult installations, and if you use high-end materials.

To save money, consider going for a three-quarter bathroom rather than a full bathroom. A three-quarter bathroom includes a sink, toilet, and a shower, but no bathtub. If you already have a bathtub in another bathroom, a three-quarter bathroom addition is a great money-saving solution.

Must I Get Permits to Add a Half Bathroom to My Home?

In general, yes!  In most cities and towns in the United States, if you make alterations to your home’s structure, plumbing or electrical systems, you must take out a permit. The permit will require the work to be inspected by the building officials to ensure it meets building codes.

You can expect your building permits to cost between $50 and $2,000. These costs depend on the complexity of your project and local ordinances. Before starting any remodeling project in your home, you should consult with the local building inspection office for advice on permits and requirements.

Adding a Bathroom to an Existing Space

A bathroom addition in the existing space will be a lot cheaper than building out a brand new space for a bathroom. HomeAdvisor says that adding a bathroom to the existing space will cost the average homeowner about $15,000. When broken down even further, bathroom additions to an existing space can cost $125 to $250 per square foot.

Want to save even more money with your bathroom addition? Renovate the smarter way: If you convert a space that already has the plumbing you'll need—like your laundry room—you can save money on plumbing and draining costs. Additionally, placing new bathrooms directly above or below existing ones can be cheaper for those same reasons, too.

What is the best way to build a small bathroom?

33 Small Bathroom Ideas to Make Your Bathroom Feel Bigger

  1. Keep Your Colors Light and Bright. © Emily Gilbert Photography.
  2. Or Double Down on Dark Color.
  3. Mirror a Wall.
  4. Or Incorporate Multiple Mirrors.
  5. Opt for a Glass Shower Door.
  6. Or Remove Your Shower Door Completely.
  7. Backlight the Mirror.
  8. Take On Tile.

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.

What are the Benefits of adding a Half Bathroom?

Installing a half bathroom in your home will ultimately increase the value of your home. On average, installing a half bath will add 10% to your home’s value.

This bathroom also provides a convenient and easy to access bathroom for guests and family members. Since it is a half bath, it is much easier to clean and maintain than a larger bathroom as there is only a toilet and a sink. 

How much does it cost to remodel a kidsbathroom?

It costs an average of $5,000 to $11,000 to remodel a tiny full bathroom, or $120 to $275 per square foot. The cost varies based on the materials, finishes, and fixtures that are chosen. When employing low-cost fixtures and finishes, remodeling a children’s bathroom is less expensive.

Frequently Asked Questions

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. 

How much does it cost to plumbing a new bathroom?

Plumbing a new bathroom may cost anywhere from $10,000 to $25,000, depending on whether or not you have to go through a foundation to do it. Many customers prefer to save money by leaving the half bath close to existing plumbing (for example, on a shared wall with another bathroom) or by adding a Saniflo toilet system.

See also:   How To Refinish Interior Wood Doors?

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

Bathroom Addition Cost

The average cost to add a bathroom addition to an existing space is $7,600 with some homeowners paying as little as $2,500. The cost to build a new bathroom addition to your house will cost around $22,000 on average, or $47,000 to $87,000 on the high-end.

Average Cost To Add A Bathroom
National Average Cost $7,600
Minimum Cost $2,500
Maximum Cost $25,000
Average Range $4,500 to $12,400

Convenience and Cost – Balancing the Half Bathroom Addition

The addition of a half bathroom in some homes balances the costs of the addition with the convenience the new bathroom brings. Half bathroom additions typically return ten to fifteen percent of their cost to the value of the home. However, having that half bathroom on the first floor can add a level of livability to your home that more than offsets the cost.

Related Guide

Dennis Howard Dennis is a retired firefighter with an extensive background in construction, home improvement, and remodeling. He worked in the trades part-time while serving as an active firefighter. On his retirement, he started a remodeling and home repair business, which he ran for several years.


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