Mountain View, CA

How Much Does It Cost To Add A Bathroom?

$2,500 – $12,500 Remodel Exisiting Space
$18,000 – $47,000 Build A New Addition

The average cost to add a bathroom addition to an existing space is $7,600. Adding a simple bathroom costs as low as $2,500 by remodeling existing space or $22,000+ for a new home addition. The cost depends on if you are using existing space within the home or building onto the house. Get free estimates from bathroom addition contractors near you.

Bathroom Addition Cost

The average cost to add a bathroom addition to an existing space is $7,600 with some homeowners paying as little as $2,500. The cost to build a new bathroom addition to your house will cost around $22,000 on average, or $47,000 to $87,000 on the high-end.

Average Cost To Add A Bathroom
National Average Cost $7,600
Minimum Cost $2,500
Maximum Cost $25,000
Average Range $4,500 to $12,400

Cost To Add A Bathroom Chart Infographic

Table Of Contents

  1. Bathroom Addition Cost
  2. Average Cost To Add A Bathroom
  3. New Bathroom Installation Costs
  4. Cost To Build A Bathroom
  5. Half Bath or Full Bath?
  6. Hiring Your Bathroom Addition Contractor
  7. Home Addition Contractors

Average Cost To Add A Bathroom

Overall you should be able to add a simple bathroom for as low as $2,500 by remodeling existing space or about $22,000 for a new addition. No matter where in the home you are adding a bathroom, the cost will mainly depend on whether you are using existing space within the home or building onto the house. [1]

Cost To Add Bathroom To Existing Space

The average homeowner spends about $7,600 for turning existing space into an 80–100 square foot bathroom. [2] Whether you’re adding a bathroom in the back of the house to use as a mudroom, or in the master bedroom to use as an en-suite bathroom, additional bathrooms add to your home’s value and increase convenience. If you spend $47,400 on an upscale bathroom remodel, it will increase add value to your home by about $28,700. [3]

Cost To Add Bathroom To A Basement

Adding a new basement bathroom costs up to $15,200 for a 6x8 powder room with 8-foot high ceilings. Plumbing labor fees add $720 to $1,350 for setting up a new sewage-ejector system that moves your waste water up and out of the basement area. Most costs for other bathroom fixtures in a basement are about the same as in other bathrooms.

Bathroom Addition Cost Estimator

New Bathroom Installation Costs
Fixture Installed Average Lowest to Highest
Shower/Tub $500–$1,000 $400–$3,900
Tile $4–$7/SF $4–$9/SF
Toilet $250–$400 $270–$3,200
Sink/Vanity $180–$550 $200–$4,600
Flooring $4–$8/SF $2–$100/SF
Plumbing $800 $600–$1,200
Electrical Work $500 $350–$700

New Bathroom Addition With Interior Tile Floor and Vanity Cabinet and Shower

Bathroom Addition Cost Factors

Many variables affect how much your bathroom addition will cost such as:

  • Location – If the new bathroom is near existing plumbing, it will cost less than if you need to bring plumbing, vents, and waste lines to the new bathroom.
  • Size – Will you need to knock out walls to make room for the new bathroom or will it go into an unused walk-in closet? Most bathroom additions are inside the home, meaning you won’t have to build out a foundation or add a roof to it.
  • Scale – Will this be a practical bathroom or a luxe addition to the master bedroom?
  • Age of your home – Will the plumbing or electrical work need to be updated before the addition can proceed?
  • DesignArchitect hourly rates are $100 to $250 per hour to design the bathroom.
  • The unknown – Once you begin opening walls and looking into attics, crawlspaces, or basements, you may find some unexpected problems. There could be mold in the walls or a water leak. You might find evidence of pests or asbestos. It’s a good idea to put some extra money in your budget for the unexpected. If you don’t see anything surprising, you can use the extra money to upgrade one of the aspects of your bathroom addition.

New Bathroom Installation Costs

New bathroom installation costs $7,600 on average with most homeowners spending between $4,500 and $12,400 when adding a bathroom to an existing space. Your final cost will depend on if it's a half or full-bath and the quality of materials used.

High-End Bathroom Addition Built With Luxury Appliances, Custom Vanity, Tub, And Walk-in Shower

Shower or Tub Installation Cost

When remodeling your bathroom, a shower/tub combo can be installed for $800–$2,900. Other installations can be figured from the plumber’s hourly rate of $140.

Are you installing a shower, tub, or shower/tub combination? Many larger bathrooms have a separate shower and tub, while bathrooms that are short on space will combine the two into one area. If you're set on installing a bathtub, bear in mind that a full cast iron or steel tub will add 400 lbs. to the floor load, and your home’s floor joists are unlikely designed to handle the pressure.

"When adding a tub, reinforce the floor joists and add cross-bridging between joists. You may also need to double the studs. Even a shower stall can stress floor joists that weren’t designed to support bathroom fixtures." [4]

Lowe’s pricing is as follows:

  • Showers can be as small as 32 x 32 and cost as little as $290 (includes walls, base, showerhead, shower valve, shower curtain, curtain rod, safety railing).
  • You can get a 41” corner unit steam shower for $5,230.
  • A simple, one-piece tub/shower unit costs about $430.
  • A 36” x 60” whirlpool tub is about $1,440.
  • A modern, freestanding tub that is 34” x 63” and holds 53 gallons of water is $799.
  • You can also go the custom-built way and get a shower as large as a small room with multiple shower heads and other luxe amenities.
  • For seniors or those with limited mobility, a walk-in tub costs $3,000 to $10,000 installed.

A tub can be set and fastened in place for approx. $90 in labor costs before attaching to a water supply and drainage system, while setting and fastening a whirlpool tub will cost about $145. A simple removal of the tub will cost about $30, but add on the cost of dump fees and repairs to the wall and floor.

Planning To Build A New Bathroom Addition Drawing and Rendering

Bathroom Tile Installation Cost

Tile is an excellent choice for countertops, walls, and the floor because of its water resistance and affordability. The average cost to install tile flooring is $10 to $15 per square foot.

The average cost to install tile a shower or bathroom walls ranges from $7 to $25 per square foot. The price to tile a walk-in shower with 84 SF of walls ranges from $546 to $2,100 depending on what type of material you select.

Tile installation runs from $3.50–$7/SF when you supply the tile. Various tile choices include terracotta, stone—marble, granite, and limestone—glass, metal, slate, and porcelain.

Beautiful Bathroom Addition With Whirlpool Bathtub and Walk-in Shower

Toilet Installation Cost

Every bathroom needs a toilet and sink. On average, a standard toilet installation costs between $122 and $228, with most homeowners spending around $150 to $180. Add the price of the toilet, which averages $99 to $199 for a total toilet replacement cost of $221 to $427.

Today, toilets are using less water than ever before. Some toilets use a little as 1.2 gallons per flush (GPF), as opposed to the old toilets which could use up to 7 GPF. The difference can represent significant savings on your water bill. Secondly, there are new toilets that are state of the art and use remote controls to open/lower the lid, turn on ambient lighting, and adjust water flow in the bidet.

Building A New Bathroom With Lavender Walls In Old Style Half Bathroom With White Ceramic Sink and Toilet

Sink Installation Cost

The cost of sink installation varies by the type of sink but generally runs from $230 to $450 to install it and attach the faucet to the water lines. There are several types of sinks designed for bathrooms including:

  • Undermount sink – this sink is installed under the counter easily and looks clean and modern. Costs from $40–$2,080. [6]
  • Pedestal sink – a free-standing sink with no counter, and all plumbing is hidden inside the base. Costs from $60–$300. Some pedestal sinks are one piece, while others allow you to pick the sink and base separately.
  • Drop-in sink – drops into a space cut into the counter. It looks clean and sleek, with a cost from $35–$1,950.
  • Vessel sink – sits on top of the counter. It looks like a bowl and is attached by the drain and costs from $80–$2,690.
  • Wall-mounted sink – this sink is attached directly to the wall and has no counter or vanity and costs from $42–$1,560.
  • Corner sink – A corner sink attaches directly to the wall and is perfect for a small bathroom or powder room. One costs $120–$790. [7]

Bathroom Vanity Installation Cost

Installation of bathroom vanities starts at $45 an hour for labor only. There will be an additional cost for the sink installation and new plumbing. For this kind of work, plumbers charge approximately $122 an hour.

Vanities are the main piece of furniture in the bathroom. They can range from a few shelves to a very nice-looking piece of furniture, complete with drawers. They come in widths varying from 24”–72”. Their primary purpose is to provide storage for bathroom articles and provide a place for the sink. Today, vanities are made from cabinets, sometimes matching the cabinets in your kitchen or custom designed to look like expensive furniture.

  • 24” – Designed for small spaces and to hold one sink. From $70–$2,200. [8]
  • 30” – Holds one sink and costs from $140–$2,750.
  • 36” – From $180–$3,900
  • 48” – From $330–$,3900.
  • 60” – At this size, you can put two sinks in the top. From $410–$4,170.
  • 72” – From $1,030–$4,370.

Newly Added Bathroom With A White Vanity Cabinet And Grey Counter Top

Bathroom Flooring Installation

The average cost to tile a bathroom floor is $300 to $600 for a small 40 SF area, $563 to $1,125 for an average 75 SF bathroom, and $1,200 to $2,400 for a massive 160 SF bathroom.

Bathroom Tile Installation Cost
Tile Type Small (40 SF) Average (75 SF) Large (160 SF) Huge (210+ SF)
Ceramic $300 $563 $1,200 $1,575
Porcelain $480 $900 $1,920 $2,520
Natural Stone $540 $1,013 $2,160 $2,835

The best solutions for flooring are those that are waterproof, such as tile. They are easy to clean and stand up to the strong cleaners you want to use in a bathroom. You also want to make sure the bathroom floor is not slippery when wet. Textured tiles and area rugs can help with this.

  • Vinyl floor – comes in a myriad of colors and patterns and is available at your local home improvement store. It comes in 12’ wide rolls as well as 12” square tiles. It generally runs about $3–$10 a square foot
  • Ceramic tile – also available in a staggering array of colors and textures. Purchase for $1–$3 a square foot and have it installed for $5–$10 a square foot
  • Porcelain tile – a slight upgrade from ceramic, it’s harder than ceramic and less porous. It’s a good choice for a bathroom and costs $3–$8 per square foot tile.
  • Stone – An excellent choice for bathrooms, but they can cost a little more. Look into granite, marble, limestone, or slate tile for bathroom floors. Expect to pay from $5–$12 per square foot tile for this option.

Radiant floor heating can add up to $2,000 to your installation costs, or $10 to $20 per square foot depending on the size of your bathroom.

Install Bathroom Backsplash

The cost to install a tile backsplash in your bathroom will range from $23 to $35 per square foot, depending on the materials you select. Your rate depends on the amount of square footage to be tiled and the type of tile being used. A backsplash is a protection of the wall behind the sink, protecting it from water “splashed back” while using the sink. It works well as a tile accent for a more expensive tile.

Cost To Build A Bathroom

The cost to build a new bathroom addition to your house will cost around $22,000 on average, or $47,000 to $87,000 using high-end materials. Professional plumbers and electricians will chart $85 to $120 per hour and permits for a new home addition cost between $200 and $500.

Classy Half Bathroom Addition With Small Oval Window and Beige Tile Floor

Cost To Plumb A Bathroom

At $85–$120 per hour for plumbing labor, plumbing your new bathroom can run from $610–$1,180 for labor only using mid-grade items—not high-end components, which cost more to install. You’ll need hot and cold water for both the sink and shower/tub and a water line and sewage pipe for the toilet. If you have a basement or crawlspace, it will cost less than a concrete slab that needs to be cut through.

Electrical Work for a Bathroom Addition

Electricians charge from $85–$120 an hour (labor only) to work on a home addition, depending on where you live. You’ll need new electrical work for

  • outlets,
  • fans, and
  • adequate lighting.

You’ll need to install GFI (ground fault interrupter) outlets because of the proximity to water, and you have to add a vent to the exterior if there is no bathroom window. If you add showers and toilets with tech components, you’ll need to wire the bathroom for those as well.

Permits and Legal Regulations

You’ll need to check in with your local building department to find out about necessary permits. Building codes often include minimum bathroom dimensions; the smallest two-fixture bathroom is 5’ x 4’. Some HOAs have regulations about home additions. If you have a general contractor overseeing this job, he or she will know what you need to proceed legally, but in general, you’ll need permits for:

  • Adding additional space to the home and building new walls
  • Any electrical work – all wiring must be up to code
  • Any other plumbing and waste ducts and pipes brought to a new location

Having permits ensures all work is done to meet the building codes in your county. It will be inspected once completed, so you can rest assured that everything is as it should be. Costs vary depending on where you live, but permits run in the region of $200 to $500.

Half Bath or Full Bath?

A full bath has a sink, toilet, and shower or tub. Full bathrooms are typically added to the master bedroom or are on another floor beside the main floor. Converting a half bath to a full bath can increase your home’s value by up to 20%.

A half bath only has a sink and toilet. Extra bathrooms are usually found near the front of the home as a place for guests to use the facilities without tromping through your house. Small bathrooms can also be useful in the laundry room, mudroom, or garage/workshop. If you're working with a small space, consider a three-quarters bath, which is a half bathroom with only a shower.

Add A Half Bath With White Pedestal Sink Mirror And Toilet

A half bath should be three to four feet wide, and six to eight feet long, or around 18 to 30 square feet. According to the National Association of Home Builders, adding a half-bathroom can add 10 percent to your home's value. The decision to add a full or half bath will come down to a few factors:

  • What is its purpose?
  • Where will it be?

Hiring Your Bathroom Addition Contractor

On average, a bathroom addition has a return on investment (ROI) of 50% to 60% which is one of the most significant home improvements you can make to increase your resale value. To get the best contractor for your job, make sure they fit the following list:

  • Licensed, bonded and insured
  • Great online reviews
  • Detailed estimates from 3–5 different companies, which includes all cleanup.
  • Member of professional organizations
  • Start and end dates

How To Save

A few things you can do to lower the total cost of the bathroom you want to add are:

  • Make it smaller.
  • Buy less expensive components. Prioritize your want list.
  • Do some of the more accessible work yourself—demolition, picking up the new fixtures, painting.
  • Use the existing plumbing.

Get free estimates on HomeGuide from trusted bathroom addition pros:

Get free estimates


[1] https://www.saniflodepot.com/pages/how-much-cost-to-add-bathroom

[2] https://bathrooms.promatcher.com/cost/

[3] https://www.remodeling.hw.net/cost-vs-value/2019/

[4] National Estimator 2018

[5] National Estimator

[6] Prices from Lowe’s

[7] Prices from Home Depot

[8] Prices from Lowe’s

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