Written by

Tom Grupa

April 5, 2023

Bathroom Addition Cost

The average cost to add a bathroom 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

The cost to add a bathroom can be as low as $2,500 when remodeling an existing space to a simple bathroom or about $22,000 for a new addition. No matter where in the home you are adding a bathroom, the cost mainly depends on whether you are using existing space within the home or building onto the house.

Cost To Add Bathroom To Existing Space

The average homeowner spends about $7,600 for turning existing space into an 80- to 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 your home's value by about $28,700. [3]

Cost To Add Bathroom To A Basement

Adding a new basement bathroom costs up to $15,200 for a 6' x 8' 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 wastewater 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

Bathroom Addition Cost Factors

Factors that affect the cost include:

• 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?

  • The cost to rewire a house is $5 to $17 per square foot.

  • The cost to install new plumbing pipes is $450 to $1,800 per fixture.

• Design – Architect 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 $4,500 to $12,400 when adding a bathroom to an existing space. The final cost depends on if it's a half or full-bath and the quality of materials used.

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 $45 to $150.

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."

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, and safety railing).

• A 41” corner unit steam shower costs $5,230.

• A simple, one-piece tub/shower unit costs about $430.

• A 36” x 60” whirlpool tub costs $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 approximately $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.

Bathroom Tile Installation Cost

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

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

Tile installation runs from $3.50 to $7.00 per square foot when you supply the tile. Various tile choices include terracotta, stone—marble, granite, and limestone—glass, metal, slate, and porcelain.

Toilet Installation Cost

Every bathroom needs a toilet and sink. On average, a standard toilet installation costs $250 to $750 for materials and labor. The labor alone costs $120 to $230.

• Today, toilets are using less water than ever before. Some toilets use as 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.

• Some new toilets are state-of-the-art and use remote controls to open/lower the lid, turn on ambient lighting, and adjust the water flow in the bidet.

Sink Installation Cost

The cost of sink installation varies by the type of sink but generally runs from $230 to $650 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 to $2,080.

• Pedestal sink – a free-standing sink with no counter, and all plumbing is hidden inside the base. Costs from $60 to $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 to $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 to $2,690.

• Wall-mounted sink – this sink is attached directly to the wall and has no counter or vanity and costs from $42 to $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 to $790.

Bathroom Vanity Installation Cost

Installation of bathroom vanities starts at $45 per 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 to $2,200.

• 30” – Holds one sink and costs from $140 to $2,750.

• 36” – From $180 to $3,900

• 48” – From $330 to $,3900.

• 60” – At this size, you can put two sinks in the top. From $410 to $4,170.

• 72” – From $1,030 to $4,370.

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 large 160 SF bathroom.

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 to $10 a square foot

• Ceramic tile – available in a staggering array of colors and textures. Purchase for

  $1 to $3 a square foot and have it installed for $5 to $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 to $8 per square foot.

• 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 to $12 per square foot tile for this option.

• Heated flooring – Radiant floor heating costs $1,500 to $6,400 depending on the size of your bathroom.

Install Bathroom Backsplash

The cost to install a tile backsplash in your bathroom is $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 is $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.

Cost To Plumb A Bathroom

At $85 to $120 per hour for plumbing labor, plumbing your new bathroom can run from $610 to $1,180 for labor alone 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 $50 to $130 an hour (labor only) to work on a home addition, depending on where you live.

• A new GFCI outlet costs $150 to $350 installed and is required in bathrooms due to the proximity to water.

• The cost to install a bathroom exhaust fan is $250 to $950 for the fan and labor to vent to the exterior if the new bathroom does not have a window.

• The cost to install a new light fixture is $70 to $250, depending on the type.

Permits and Legal Regulations

Costs vary depending on where you live, but permits cost $200 to $500 on average. Check 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.

Half Bath or Full Bath

Converting a half bath to a full bath can increase your home’s value by up to 20%. 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.

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.

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% 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, get at least three estimates to compare, and make sure they fit the following list:

• Licensed, bonded, insured, and in business for 5+ years.

• Have great reviews on HomeGuide and Google.

• Member of professional organizations

• Provide 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.

Questions to ask contractors

• How long have you been in business?

• Are you licensed, bonded, and insured?

• What is and is not included in the estimate?

• What additional costs should I expect?

• How long will the installation take?

• Is a warranty included, and if so, what does it cover?

• What do you charge for repairs?