What Does It Cost to Add a Half-Bath?

Other than remodeling your kitchen, did you know that remodeling your bathroom and adding a half-bath are two of the most popular home improvement projects? And beyond being popular choices, they’re also wise investments. On average, homeowners see a 60 percent ROI when it’s time to sell their house.

Naturally, your space considerations and budget will affect the overall cost of how much to add a half bath in your house. But since there are certain common factors that have an impact on half-bath additions, it’s good to know where you can either wisely save money or make more of an investment to satisfy your tastes and keep value in your property.

Here are some of the issues to consider when asking yourself, “How much does a half-bath addition cost?”


Other than plumbing issues, which we’ll discuss next, there are two main things to consider when deciding where to locate a half-bath. Space and privacy must be taken into account. Most half-baths require a minimum of three to four feet in width and six to eight feet in length. Additionally, it’s advisable to have the doorway open away from a direct line of sight to your living or dining areas so your guests can enjoy privacy when entering and exiting.

If you have a separate hallway with sufficient space under a stairwell, you may already have the right location for a half-bath that doesn’t require extensive construction to complete.


One of the biggest costs associated with a half-bath addition is the expense of adding the necessary plumbing. If your house has a basement or is supported by piers, then running additional plumbing under the floor isn’t too much of an issue. If, however, your house has a slab foundation, there will be more work required to install the new plumbing line, such as the use of jackhammers and patch tools.

Remember that installing your half-bath close to existing plumbing will always help keep costs down.


Since you want your guests to feel comfortable in your new half-bath, you’ll need to include a sink, mirror and toilet as the bare minimum. If you have the room for a vanity or storage cabinet, it’s always a nice touch. Just don’t make the space feel too cramped. However, if space isn’t a problem, homeowners with an eye on their home’s resale value might consider making the half-bath into a three-quarters-bath by adding a shower.


According to building codes, you’ll have to ensure that your half-bath has proper ventilation. In most cases, this means installing either an operating exhaust vent or a window.


To protect against electric shock due to outlets in close proximity to water sources such as sinks, showers and toilets, you’ll need to install ground fault circuit interrupters, or GFI circuits, and outlets.

If you consider these factors carefully, you’ll be ready to do the math and find out what it costs to add a half-bath to your house. Of course, for a free, no-obligation estimate for your bathroom redesign, simply contact us today.


Angies 2018
Angies List 2020
Angies 2021
Angies List 2022
Home Advisor
Elite Service
10 Years Home Advisor
Nari Member
Master Elite
A Rating