How much does it cost to put a bathroom in the basement?
How much does it cost to put a bathroom in the basement?
$3,000 – $12,500 cost to convert an existing space
$6,000 – $27,500 cost to build a home addition
Average cost to put a bathroom in the basement
The average cost to add a bathroom to a basement is $200 to $250 per square foot, or $3,000 to $12,500 for 15 to 50 square feet, including new plumbing, electrical, and interior finishes. Extending your basement and adding a bathroom costs $400 to $550 per square foot due to major projects like framing and foundation work.
| Project type | Average cost per square foot |
Average total cost* |
|---|---|---|
| Converting existing space | $200 – $250 | $3,000 – $12,500 |
| Home extension / addition | $400 – $550 | $6,000 – $27,500 |
*For 15 to 50 square feet
Converting existing space
Converting part of your basement into a bathroom costs $200 to $250 per square foot or $3,000 to $12,500 total with professional installation, depending on the size. Areas with easier access to utilities can help cut labor bills. No need for new exterior walls or roofing keeps costs lower.
Conversion projects are less expensive since you're working within the home's current structure, while additions involve foundations, new walls, and more complex permitting.
Home extension / addition
Building an addition for a basement bathroom costs $400 to $550 per square foot or $6,000 to $27,500 total, since this covers new foundations, walls, exterior work, and utility extensions. This is a good fit if your basement does not have enough unfinished area to convert.
Basement bathroom cost by size
The bathroom size impacts significantly impacts the cost. A small 15-square-foot half bathroom costs less than a full primary bathroom with a tub or shower. Converting a storage space or closet can give you 25 to 75 square feet.
| Bathroom size | Square feet | Average conversion cost | Average addition cost |
|---|---|---|---|
| Small half bath | 15 – 20 | $3,000 – $5,000 | $6,000 – $11,000 |
| Small 3/4 bath | 25 – 40 | $5,000 – $10,000 | $10,000 – $22,000 |
| Medium full bath | 40 – 50 | $8,000 – $12,500 | $16,000 – $27,500 |
| Large full bath | 50 – 100 | $10,000 – $25,000 | $20,000 – $55,000 |
| Primary bathroom | 100 – 200 | $20,000 – $50,000 | $40,000 – $80,000 |
For ADA accessibility, the minimum bathroom size is 5' x 5', or 25 square feet.
What affects the cost to add a bathroom to a basement?
Many variables affect the basement bathroom cost. Think about each before starting your project:
Material and fixture quality: Premium tile, lighting, and hardware can add to your budget. Finishing your space with plush rugs or a high-quality accessory set costs more.
Bathroom layout: Larger or irregular bathroom layouts cost more in framing, flooring, and fixtures.
Sewage ejector system: Below-grade basements must pump wastewater up to your home's drain lines. Adding an ejector pump costs an extra $2,000 to $5,500.
Existing plumbing: If pipes and drains are already present, it can reduce costs dramatically.
Waterproofing and radon: Basements need extra water and air protection for occupant safety. Radon testing costs $10 to $400. Basement waterproofing costs $6 to $15 per square foot.
Permitting and code compliance: Permit costs and inspections vary based on region and scope.
Basement bathroom cost by project
The cost to put a bathroom in the basement depends on the fixtures and finishes you choose. Prices can vary significantly based on the quality and style. Standard fixtures like pedestal sinks or ceramic tile flooring cost less. Premium features like natural stone countertops, custom cabinets, or heated floors cost more.
The following table shows the cost to put a bathroom in a basement by project:
| Fixture | Average installation cost |
|---|---|
| Shower installation cost | $1,000 – $15,000 |
| Bathtub installation cost | $1,200 – $6,600 |
| Toilet installation cost | $350 – $800 |
| Sink and faucet installation cost | $580 – $2,000 |
| Countertop and vanity installation cost | $400 – $4,000 |
| Tile flooring cost | $220 – $2,500 |
| Rough-in plumbing cost | $450 – $1,800 |
| Electrical wiring cost | $200 – $850+ |
| Light fixtures installation cost | $100 – $300 each |
| Exhaust fan installation cost | $250 – $950 |
| Mirror installation cost | $140 – $430 |
| Medicine cabinet | $150 – $400 |
Basement bathroom remodel cost
Remodeling an existing bathroom costs $100 to $500 per square foot or $3,500 to $7,500 for a minor renovation. A full remodel, including major layout changes or luxury materials, costs $8,800 to $25,000+.
Remodeling a basement costs $25 to $65 per square foot or $12,500 to $37,500 and often includes bathroom projects as well as adding a home theater, installing a wet bar, or adding an egress window to convert it into a living space.
Looking for inspiration? Explore our Bathroom design ideas to get your creative juices flowing!
Do's and don'ts for adding a basement bathroom
Smart planning can help save you money and maximize the use of your space. Consider these when designing your bathroom:
Layout efficiency: Position the bathroom below or near existing plumbing for lower costs.
Accessibility: Include wide doorways and barrier-free showers for long-term value.
Natural light: If possible, use or install egress windows for safety and ambiance.
Storage: Add shelving or built-ins to maximize limited space for towels and toiletries.
Avoiding costly errors saves time and money. Industry experts avoid issues like:
Skipping permits or inspections: Proceeding without the proper documentation can cause hefty fines or force redo.
Ignoring waterproofing: Not sealing properly leads to mold, mildew, and future repairs.
Inadequate ventilation: Lack of a vent fan or poor airflow causes moisture problems.
Improper plumbing slope or drainage: Poor waste line angles can mean frequent back-ups or clogs.
Not planning lighting: Basements need well-placed, layered lighting for function and safety.
Basement bathroom addition FAQs
Can you add a bathroom to a basement?
Yes, you can add a bathroom to a basement, regardless of whether the basement is finished or unfinished. You just need permits, proper drainage, and a safe ventilation system.
Can you install a basement bathroom without breaking concrete?
Yes, you can install a bathroom in your basement without demolition. Solutions like ejector pumps and macerating toilet systems allow installation without jackhammering your basement slab. These systems pump wastewater upward to the home's main plumbing drainage stack.
How long does it take to add a bathroom to a basement?
Adding a bathroom to a basement takes 2 to 5 weeks, depending on complexity, labor, and permitting timelines.
Does adding a bathroom in the basement add value?
Most experts say adding a basement bathroom can give you a 50% to 75% return on investment in resale value, but exact returns depend on your local market and the quality of the addition. For more information on related projects, check out our guide on home improvements that add value.
Getting estimates from bathroom installers
Follow these tips when navigating the estimation process. They'll help you get comprehensive, accurate quotes from bathroom installation contractors:
Identify if you have existing plumbing rough-ins to share with contractors for better accuracy.
Always get multiple detailed bids outlining all major cost components.
Verify the company's reviews on HomeGuide and Google.
Ask for itemized breakdowns of labor, materials, and permit fees.
Get references from other basement bathroom clients.
Compare inclusions such as fixtures, ventilation, waterproofing, and code updates.
Questions to ask a bathroom installation contractor
Asking these questions can improve the success and value of your bathroom project:
Does your bid include all permits and inspections?
Have you managed basement bathroom projects of similar scope before?
Will you use subcontractors for electrical or plumbing, and are they licensed?
Can you match the color and materials in the rest of my home?
What is the project timeline, including best- and worst-case scenarios?
Will you need to order any materials, or do you have them on hand?
How will you handle surprises with plumbing runs or foundation work?
Do you offer warranties on your labor? If so, what does it include?
Using our proprietary cost database, in-depth research, and collaboration with industry experts, we deliver accurate, up-to-date pricing and insights you can trust, every time.