How Much Does It Cost to Add a Bathroom to a House?

If you believe that your old bathroom doesn’t work for you anymore, especially if you share it with other people, it is time to think about adding a new bathroom. The only problem is that the cost of adding a bathroom can be expensive. That’s what puts off most homeowners, but they fail to account that they will be rewarded with a higher home resale value and a more functional living space with new bathroom addition.

So, if you’re trying to calculate how much it costs to add a bathroom to a house, you have come to the right place. In general, the average cost of a bathroom addition to your home is around $7,500. If you’re remodeling your existing space, it could cost between $2,500 to $12,500, while building a new addition could be anywhere between $18,000 to $47,000 depending on your preferences. The table below showcases the average cost to add a bathroom to a house.


National Average Cost

How Much Does It Cost to Add a Bathroom to a House?




Minimum Cost




Maximum Cost




Average Range


$4,500 to $12,400

Average Cost to Add a Bathroom to a House

In total, you should be able to add a bathroom to your home for around $2,500 if you choose to remodel the existing space. However, if you plan on a new addition, it could cost you around $22,000. Regardless of where you are adding your bathroom, the cost will depend on whether you’re building onto the house or using the existing space.

Cost to Add Bathroom to Existing Space

On average, a homeowner would spend around $7,600 to turn an existing space into a bathroom between 80 to 100 square feet in size. Whether you’re adding a bathroom in the master bedroom or at the back of the house, additional bathrooms will increase your home’s value and add more convenience to your life. If you’re spending $47,000 on an upscale bathroom remodel, it will increase your home’s value by $30,000, which is why it is worth the investment.

Cost to Add Bathroom to a Basement

You can expect to spend around $15,000 to add a new bathroom to your basement. You should set aside $700 to $1,300 for plumber labor fees and set up a new sewage-ejector system that will move your wastewater out of the basement area. The costs for bathroom fixtures for a basement bathroom will be the same as in other bathrooms in your home.

We are sharing a bathroom addition cost estimator table to give you a decent idea about the overall new bathroom installation costs. These are as follows:





Installed Average


Lowest to Highest




$500 to $1,000

$400 to $3,900




$4 to $7 per square feet

$4 to $9 per square feet




$250 to $400

$270 to $3,200




$180 to $550

$200 to $4,600




$4 to $8 per square feet

$2 to $100 per square feet





$600 to $1,200


Electrical Work



$350 to $700

Cost Factors for Bathroom Addition to a Home

Several variables should be taken into account when adding a new bathroom to your house. These will affect the overall cost of a bathroom addition and are as follows:

  • Location

If your new bathroom is close to existing plumbing in the home, it will cost less because you won’t need to bring waste lines, plumbing, and vents to your new bathroom.

  • Size

The overall size of the bathroom will also affect the cost. Do you have to knock down walls to make room for the bathroom, or will you use a walk-in closet? In general, bathroom additions are made inside the home, so you won’t need to add a roof or build a foundation for it.

  • Scale

The scale of the bathroom should also be taken into account. For instance, do you plan on adding the bathroom to your master bedroom like a luxury en-suite or want a practical bathroom in the house? The scale you decide on for the bathroom will affect the cost.

  • Home’s Age

The age of your home will affect the costs of adding a new bathroom. If the electrical work or plumbing needs to be updated before adding the new bathroom, it will increase your costs.

  • Design

If you’re hiring an architect to design the new bathroom addition for your home, you can expect to pay them around $100 to $250 per hour for designing the bathroom.

  • The Unknown

You may encounter unexpected problems as you begin knocking down walls and looking into crawlspaces, attics, and basements. There could be a water leak or mold in the walls, and you may even find asbestos or a pest infestation problem. Therefore, it’s recommended to keep extra money in your budget so that you can deal with unexpected costs. If everything goes to plan and you don’t come across anything unexpected, you can use the extra money for upgrading your bathroom addition.

Our Final Thoughts

In general, adding a new bathroom to your house can offer you a significant return on investment, which could be around 50% to 60%. That’s why it is considered one of the best home improvement projects as it increases the resale value of your house. You can do a few things to lower the cost of adding a bathroom to your house by:

  • Making it smaller
  • Losing less expensive components
  • Doing some of the work yourself, like the demolition, painting, and buying new fixtures
  • Using your existing plumbing

Even though the cost to add a bathroom to your house can be an expensive proposition, you can reassure yourself that you’ll be getting most of your money back when you sell your home.