There’s a lot to love about a new bathroom addition, especially when it’s part of a full master suite. You get to enjoy the upgraded finishes, the better layout, and the comfort of a space that finally fits the way you live. But with every addition comes a long list of decisions, and cost is always near the top.
At Koch Construction, we’ve worked on plenty of these projects. While every home is different, the core of the process stays the same. You’re adding space, improving the way your home functions, and building something that’s meant to last.
A Closer Look at a Master Suite Addition
In one recent project, we completed a full master suite addition for a homeowner looking to create a space that felt custom-built from the start. The work included a new bedroom, a walk-in closet, and a bathroom filled with thoughtful, high-end details.
The bathroom featured:
- A ceramic tile walk-in shower, built with long-term durability in mind
- Heated tile floors for added comfort in the colder months
- A freestanding soaking tub that gave the room a true focal point
- A custom vanity with quartz countertops, designed to fit the space and tie everything together
These are the elements that make a new space feel personal, but they’re only part of the overall cost.
What Really Adds to the Price of a Bathroom Addition
Most people tend to focus on the finishes (tile, tubs, vanities), but much of the cost comes from the work that happens behind the walls and under the floors. That’s where planning and experience matter most.
Here’s what typically drives up the cost of bathroom additions:
- Framing and tying in the structure to the existing home
- Connecting plumbing, electrical, and HVAC systems
- Meeting modern energy and building codes
- Insulating to meet performance requirements
- Coordinating inspections, permits, and site access
These steps aren’t as visible as the tile or the tub, but they’re what make the finished space work as a true part of the home. When this part of the job is done well, the rest of the work fits better and lasts longer.
Typical Price Range for a Bathroom Addition
If you’re looking to add a full bathroom as part of a master suite or other addition, you can expect the total cost to fall between $200,000 and $250,000 or more. The final number depends on several factors such as square footage, the complexity of the design, site conditions, and the materials selected.
We’ve found that once clients understand what goes into a project of this scale, they have a much clearer picture of the cost and the value behind it.
Common Questions About Adding a Bathroom
We get a lot of questions from homeowners trying to figure out where to start. Here are a few we hear most often:
Can you add a bathroom to an existing house?
Yes. In most cases, we can add a bathroom to your home, either by building an addition or converting an underused space. We’ll look at your layout, utility access, and structure to determine the best approach.
Is adding a bathroom a good investment?
For many homeowners, it is. A new bathroom can make a house more functional and more attractive to future buyers. It’s especially valuable in homes that currently have only one or one and a half baths.
What adds more value? A bedroom or a bathroom?
It depends on the home, but a bathroom addition often brings more everyday usability. If your house already has enough sleeping space, a second or third bathroom tends to have a bigger impact on convenience and resale appeal.
How long does it take to build a bathroom addition?
Timelines vary depending on weather, permitting, material availability, and the size of the addition. Most bathroom additions take two to three months from the start of construction to completion. Planning and design can take a few weeks before that.
Where is the easiest place to add a bathroom?
The easiest place to add a bathroom is near existing plumbing, such as next to a laundry room or above a basement utility area. However, if you’re building an addition, the layout is more flexible, and we’ll design it to fit your home’s structure and flow.
If you’re thinking about the cost to add a bathroom to your home, we’re happy to help you take the next step. We’ll walk through your goals, talk about what’s possible, and help you figure out the best approach for your home and your budget.
At Koch Construction, our goal is to build additions that feel like they’ve always been there. With the right plan and the right crew, we can make your home work better, without making it feel like a patchwork of past projects.