Bathroom addition might look like a small and simple addition in the house, but it can be so complicated to estimate and manage. Aspects such as plumbing and electrical system upgrades will definitely affect the bathroom addition cost greatly.
Besides, if you plan to add a master bathroom or an extra bathroom, you need to spend money for purchasing fixtures such as toilet, sinks, faucets, bathtub and shower. If you plan to tear out the wall between two rooms to open up the space so that it can be treated as one large room, you should also consider purchasing additional cabinets and vanities.
For these reasons, bathroom addition cost varies depending on your individual needs. The following is a guide on what you can expect to pay if you want an average cost of bathroom addition in your home.
Read also: Bath Fitter Tub To Shower Conversion Cost
Bathroom Addition Ideas
To get ideas about bathroom addition, you can visit some home improvement centers like Home Depot and Lowe’s. They offer plenty of bathroom addition ideas that you can consider before you start the project.
![Average Cost of Bathroom Addition](https://www.bathroomsimple.com/wp-content/uploads/2022/02/Average-Cost-of-Bathroom-Addition.webp)
Bathroom Addition Cost
The average cost of bathroom addition depends on where your house is located, how many bathrooms are in the house now, whether you plan to tear down walls.
Average cost of a small bathroom addition: $10,000 – $25,000 (300-600 square feet)
The size of the existing room and additional features determine the price for adding a new room to the house. A 300 square foot bathroom addition typically costs anywhere from $10,000 to $15,000. The average cost for a 600 square feet bathroom will be around $25,000.
As mentioned earlier, extra features such as jetted tubs and showers that come with multiple shower heads or massages jets will affect the bathtub installation cost . For example, you can find a bathtub for $850 where it can be installed relatively easy, but the price will increase to around $5,000 if you want to install tub models with massage jets.
Master bathroom addition cost: $30,000 – $80,000
The master bathroom is usually larger than an extra bathroom because it requires more space for features such as shower, bathtub, double sinks and more storage space.
Master bathroom addition cost is typically around $30,000 for 500 square feet room if you just want to remodel it with new fixtures. However, bathrooms that are larger than 500 square feet will cost approximately $50,000 to $80,000 on average.
![Master bathroom addition cost](https://www.bathroomsimple.com/wp-content/uploads/2022/02/Master-bathroom-addition-cost.webp)
Bathroom addition cost per square feet: $100 – $150
The average cost for a 300 square foot bathroom is around $10,000 while the same size room with additional 300 square feet will raise it to an average of $15,000. However, if you want the bathtub and shower area larger than the rest of the room or you want to have some additional features, then it will affect the total cost.
For example, if you plan on adding a jetted tub in your 300 square feet bathroom addition, it can increase the total cost by $5,000 for just installing one single feature. You should expect an average of about $100 or more per square foot for a large bathroom.
For bathroom addition garage, the price is in an average range of $5,000-10,000.
If you plan on adding a bathroom in the garage of your house or apartment, you need to consider that it is not very easy to extend plumbing so it can be done by hiring home improvement contractors. A bathroom addition cost for 300 square foot room in the garage is around $5,000 to $10,000.
![Small garage bathroom ideas](https://www.bathroomsimple.com/wp-content/uploads/2022/02/Small-garage-bathroom-ideas.webp)
New construction cost for a bathroom addition: $25,000 – $45,000
The price of new construction for a 300 square feet bathroom is generally around $25,000 to $35,000 with the average room size about 500 square feet.
However if you want to have a larger bathroom or want to add some additional features in the room, then you should expect the cost in an average of $45,000.
Converting closet to bathroom: $20,000 – $30,000
If you do not have enough space in your house for a full bathroom and you want to convert the existing closet into that bathroom instead, then it can be more expensive than building a brand new room. The average cost of converting a closet to a bathroom with 300 square feet is around $20,000.
However, if you want to add some features such as a shower and bathtub, the average cost of converting the closet into a bathroom can increase to $30,000 on average.
Adding additional 3/4 bathroom: $35,000 – $60,000
This type of home improvement project is done by adding a couple of extra sinks and a toilet to the existing bathroom. In order to add an additional 3/4 bathroom to your house, you need to hire home improvement contractors.
If you plan on adding a 3/4 bathroom in your 300 square feet room, it will cost around $35,000. However, feel free to contact local contractors for a customized quote for your project.
Adding a bathroom upstairs: $20,000 – $40,000
It is not an easy project to add an additional bathroom in the second floor of the house. It requires proper planning and there are several factors that can increase or decrease its cost. For example, if you plan on adding only half bath with just a toilet and sink without any other features, then you can expect an average of around $20,000.
However, if you want to have a full bathroom with shower area upstairs instead of the half bath, then it will cost approximately $40,000 on average.
![Add a bathroom upstairs](https://www.bathroomsimple.com/wp-content/uploads/2022/02/Add-a-bathroom-upstairs.webp)
Average basement bathroom addition cost: $45,000 – $55,000
Basement bathroom addition cost is usually around $45,000 for a 400 square feet room. If you add additional 300 square feet to it, then the average basement add bathroom cost will be around $55,000 on average. You should bear in mind that if you want to have a full bathroom with shower area and bathtub instead of just a toilet and sink, then it will cost you more.
If you plan on remodeling your bathroom, make sure to contact local contractors for free quotes. You can also check out some home improvement websites for additional information. Good luck with your project!