Adding a Whole New Bathroom to Your House? Here’s What it’ll Cost

How much does it cost to add a bathroom?

The cost of adding a bathroom to your home will vary based on your existing space, the location of the addition, the overall size of the room, and the quality of the features. Here are a few cost estimates from popular platforms:

HomeGuide

• Converting an existing space: $5,000 to $25,000
• Adding a new bathroom: $20,000 to $75,000
• Adding a small half bath (15 to 20 square feet): $6,000 to $10,000 
• Adding a medium-sized full bath (40 to 50 sq.ft.): $16,000 to $25,000 
• Adding a primary bath (100 to 200 sq.ft.): $40,000 to $100,000
• Methodology: HomeGuide’s estimates are based on insights from its network of over 50,000 local professionals and the millions of home improvement projects it helps homeowners complete each year.

Angi

• Converting an existing space: $200 to $250 per square foot
• Adding a new bathroom: $5,000 to $75,000
• Adding a small half bath (15 to 20 sq.ft.): $8,000 to $12,000 
• Adding a medium-sized full bath (40 to 50 sq.ft.): $18,000 to $28,000
• Adding a primary bath (100 to 200 sq.ft.): $45,000 to $100,000 
• Methodology: Angi bases its estimates on millions of real home improvement projects submitted by homeowners, along with local pricing data, to give you a realistic idea of what a project might cost in your area.

Fixr

• Converting an existing space: $200 to $250 per sq.ft. 
• Adding a new bathroom: $400 to $550 per sq.ft.
• Adding a medium-sized full bath (40 sq.ft.): $16,000 to $22,000
• Adding a primary bath (100 to 200 sq.ft): $40,000 to $110,000

What factors influence the cost of a bathroom addition?

Now that you have a general idea of what a bathroom addition can cost, it’s time to look at what really drives the price. Every home is different, so the final cost depends on factors like your layout, plumbing, materials, and the type of bathroom you’re building. Here are some of the biggest things that can affect your budget.

Proximity to existing plumbing

One of the biggest factors affecting the cost of a bathroom addition is how close the new space is to your home’s existing plumbing. If the bathroom is being built next to or directly above another bathroom, kitchen, or laundry room, contractors can usually tap into the existing water supply and drain lines, keeping labor and material costs lower. 

On the other hand, if the new bathroom is far from existing plumbing, the project becomes more complicated. Contractors may need to run new water lines, extend drain and vent pipes, or even break through concrete slabs to connect to your home’s plumbing system. These extra steps increase both labor and material costs, making the overall project more expensive.

Hiring a plumber can cost anywhere from $99 to $980, but most homeowners spend about $340. Meanwhile, rerouting one plumbing line can cost anywhere from $650 to $1,500, and the costs can go up if you factor in drywall removal, framing work, and other repairs.

“If you want to add a bathroom to the furthest corner of your house, then you can expect to spend 30% of your budget on plumbing and electrical alone,” says Andrew Holmes, Chief Operating Officer (COO) at Blockhouse Residential, an award-winning construction firm in Pittsburgh.

Home’s foundation type

Your home’s foundation also plays a big role in how much a bathroom addition will cost. That’s because the foundation determines how easy (or difficult) it is for contractors to run new plumbing, electrical wiring, and other utilities to the new space.

Homes with a crawl space or unfinished basement are usually less expensive to work on since contractors can access pipes and wiring from below the floor. In contrast, homes built on a concrete slab often require cutting through and repairing the concrete to install or reroute plumbing, which adds both labor and material costs. If your project involves extensive excavation or foundation work, expect the overall price to increase.

Dormer installation

If you’re adding a bathroom to an attic or expanding your upper floor, installing a dormer can make the space much more functional. A dormer extends outward from the roof, creating extra headroom, floor space, and natural light, making it easier to fit a full bathroom where a sloped ceiling would otherwise get in the way.

The tradeoff is cost, which is $15,000 on average. Building a dormer requires structural changes to your roof, along with additional framing, roofing, insulation, windows, and finishing work. Larger or more complex dormers will cost more, but they can turn an otherwise unusable space into a comfortable, code-compliant bathroom.

Pipe installation

Before installing plumbing, you’ll need to run plumbing pipes (water and sewage) to the location of your new bathroom, which can cost between $230 and $5,500 per fixture.

Electrical

The average electrician charges between $50 and $100 an hour, and you’ll need their services to install outlets, lighting, and fans. Additionally, if the electrical outlets are within six feet of a water source, you’ll need to install ground fault circuit interrupter (GFCI) outlets, as required by code. These usually cost between $15 and $50 each. Angi estimates electrical wiring to cost between $2 and $4 per sq.ft.

Drywall

Drywall adds to bathroom addition costs because it requires both materials and skilled labor, especially when using moisture-resistant or mold-resistant boards designed for wet areas. The price can increase further if installers need to cut around plumbing, electrical wiring, or repair uneven framing before finishing the walls. Most homeowners pay between $1.50 and $3.50 per sq.ft. for drywall installation.

Flooring

Flooring installation usually costs around $3,159 on average, but it can swing a lot depending on the material and size of the space, from as low as $200 to as high as $12,000. Here are the cost estimates for popular flooring options:

• Vinyl: $2 to $14 per sq.ft.
• Linoleum: $3 to $12 per sq.ft.
• Laminate: $3 to $13 per sq.ft.
• Tile: $15 to $20 per sq.ft.
• Stone: $6 to $20 per sq.ft.

Bathtub and shower installation

Bathtubs and showers are usually one of the biggest cost drivers in a bathroom addition because they involve both the fixture itself and complex plumbing work. Prices can vary a lot depending on the size, style, and materials, with luxury or custom-built units pushing costs much higher than basic models. 

Installation can also get more expensive if plumbing lines need to be rerouted or if the space requires extra waterproofing and structural adjustments. But on average, installing a bathtub costs $2,100, while a shower costs $8,202.

Toilet installation

A professional toilet installation will cost between $224 and $533, and toilets range widely between $100 and $3,000. Although toilets are more affordable compared to other bathroom fixtures, exact costs still vary depending on the model and features like water efficiency or smart functions. 

Labor costs may also increase if new plumbing connections or floor modifications are needed. Higher-end toilets also raise the total cost, especially when paired with upgraded finishes or specialized systems.

Additional fixtures

Based on your bathroom design, you might want to add a vanity with cabinets, which can cost from $300 to $4,00 for purchase and installation. 

Lighting

The cost to install lighting is included in electrical costs, but you’ll need to purchase the actual fixture, which can cost around $40 to $500.

Add-ons

Any specialty add-ons mean an additional line item in the price. That includes:

• Heated bathroom floors: $8 to $20 per sq.ft.
• Specialty tub or jacuzzi: $2,000 – $35,000
• Smartroom automation: $200 to $1,525

Architect fees

If you plan to use an architect for your new bathroom, employing one can cost anywhere between $2,190 and $11,550. If you go at it on your own, you’ll need to apply for permits yourself, which cost between $500 and $2,500, depending on where you live.

»Learn more: A bathroom addition can get expensive fast, and square footage plays a big role in that. Use the Square Footage Calculator to figure out your space upfront so you can plan smarter and stay within budget.

Bathroom addition: A real-life example

We reached out to Holmes to get the scoop on a recent real-life bathroom addition. Holmes specializes in ground-up new construction and rehauling existing construction. He provided an example quote for a recent bathroom addition under an existing room. Here’s a breakdown of the major costs and labor, including time and materials:

In this project, and in Holmes’ experience working with clients adding bathrooms, many of them aren’t aware of how much installing plumbing, electric, and HVAC will drive up their budget.

How much value does adding a bathroom add to your home?

How much value a new full bathroom adds to your home when you sell depends on how many bathrooms you already had.

“If you’re talking about a one, one and a half, going to a two bath, there’s going to be huge value in that. But if you’re going from a two-bed, two-bathroom, to a three-bathroom, there’s going to be less value,” says Steven Mueller, a top Charlotte, North Carolina, real estate agent who recently added a bathroom addition to his own home.

In Mueller’s opinion, adding a full bathroom to a one-bathroom home can add between $20,000 and $25,000 in value. That’s partly because a home with two full bathrooms enters a new pool of buyers. He explains it like so: “I know the same people that will buy a one-bath home will buy a one-and-a-half bath, but buyers who want a two bath, they won’t look at a one-and-a-half bath.”

As for adding a full bath to homes that have two or more baths? “It depends on the quality,” Mueller says, “but the appraisal adjustment is between $7,500 [and] $10,000.”

In terms of return on investment (ROI), a full bathroom remodel, which can cost close to $27,000, can net sellers a 74% ROI. Meanwhile, according to the Journal of Light Construction, a midrange bathroom addition costs about $60,645 and typically recoups around 53% of that investment at resale.

How to save money on your bathroom addition

Now that we have a complete breakdown of dollars and cents, let’s review ways you can save on a bathroom addition and appeal to buyers with your selections to maximize your investment:

• Place the bathroom strategically. As previously mentioned, the closer a new bathroom is to existing plumbing, the less you’ll have to pay to extend water, sewage, and electrical lines. Building a new bathroom a floor above an existing one or close to the kitchen can reduce costs.
• Buy a “used” tub and other secondhand fixtures. You might not be able to save on electrical or plumbing labor, but you can purchase used fixtures and refurbish them to reduce costs. If you have the time to spare and don’t mind browsing a little for a gem, you can end up with some great deals. The Habitat for Humanity ReStore, Craigslist, and local surplus construction warehouses often have new or “like new” fixtures, including tubs, sinks and lighting.
• Opt for luxury wood vinyl. Moisture-friendly luxury vinyl plank can be more affordable than other flooring alternatives. These flooring options come in a variety of colors and finishes suited to any bathroom, and buyers are responding to them with more interest than ever.
• Go for a tile shower over a bathtub. If you’re torn between a tiled, open shower or a bathtub, go for the shower, Anderson says. “Bathtubs are not trending right now. Buyers like open little walk-in showers without doors,” she says.

Is it worth it to add a bathroom?

Adding a new bathroom won’t come cheap, but is the value added at resale enough to make the project worth it? It’s a big project, so it’s important to weigh both the upfront cost and the potential boost in resale value before moving forward.

“I always ask my clients, if you’re going to do an improvement like that, how long are you going to stay in the property?” Anderson says. “If it’s five years or more, it could be worth the investment. But if you don’t think you’re going to stay in the property [for] one or two years, then really reconsider. You’re not going to receive that return back.”

In the end, a bathroom addition can make sense if you plan to stay in your home long enough to enjoy it and benefit from the added value. But if your timeline is shorter, you may not fully recoup the cost when you sell. 

Before committing to any renovation, use HomeLight’s Home Value Estimator to understand your current home value and make a more informed decision about whether the upgrade is worth it.