Bathroom Addition Cost
Adding a bathroom costs $25,000–$75,000 for a full bath, $15,000–$35,000 for a half bath. Costs by type, location, and what drives the price.
How Much Does It Cost to Add a Bathroom?
Adding a bathroom costs $25,000–$75,000 for a full bathroom (tub/shower, toilet, vanity) and $15,000–$35,000 for a half bath (toilet and sink only). The biggest cost variable is location: adding a bathroom adjacent to existing plumbing (back-to-back with an existing bathroom or above a kitchen) saves $5,000–$15,000 in plumbing runs.
Converting existing space (closet, under-stairs, laundry room) into a bathroom costs 30–50% less than building new square footage. A closet-to-half-bath conversion runs $15,000–$25,000. Building a new addition with a bathroom starts at $40,000 and can exceed $100,000 for high-end finishes.
ROI is strong: Adding a full bathroom increases home value by $20,000–$40,000 on average—a 50–80% return on investment. Half baths return 40–60%. Adding a bathroom to a 1-bath home has the highest ROI because it eliminates a major buyer objection.
| Scope | Low End | Average | High End |
|---|---|---|---|
| Half bath (powder room) addition | $15,000 | $22,000 | $35,000 |
| Full bath (convert existing space) | $25,000 | $38,000 | $55,000 |
| Full bath (new addition/extension) | $40,000 | $55,000 | $75,000 |
| Basement bathroom addition | $20,000 | $32,000 | $50,000 |
| Master suite bath addition | $35,000 | $50,000 | $75,000 |
Common questions.
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