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Basement bathroom prices
| Type | Range | Fixtures |
|---|---|---|
| Half bath | $5,000–$15,000 | Toilet and sink |
| Three-quarter bath | $10,000–$22,000 | Toilet, sink, shower |
| Full bath | $15,000–$35,000 | Toilet, sink, tub or tub-shower |
Fixr, 2026.
HomeGuide prices conversions of existing basement space at $200–$250 per square foot, or $3,000–$12,500 for 15 to 50 sq ft. HomeGuide also gives a 5′ × 5′ (25 sq ft) footprint as the minimum for an ADA-accessible bathroom. Fixr's basement-specific range, $10,000–$60,000, is wider because breaking the slab and adding a pump are common below grade.
| Bathroom size | At $200 per sq ft | At $250 per sq ft |
|---|---|---|
| 25 sq ft | $5,000 | $6,250 |
| 35 sq ft | $7,000 | $8,750 |
| 40 sq ft | $8,000 | $10,000 |
| 50 sq ft | $10,000 | $12,500 |
| 60 sq ft | $12,000 | $15,000 |
Why basement bathrooms cost more
- Drain elevation. If the fixtures sit below the sewer line, waste must be pumped up through an ejector pit or an upflush unit.
- Breaking concrete. Running new drains under the slab means cutting and repouring concrete. Builder rough-ins avoid this.
- Ventilation. Bathrooms need an exhaust fan ducted outside, which can be a long run in a basement.
- Ceiling height. IRC R305 requires 6′ 8″ in bathrooms, and 6′ 8″ above a 30″ × 30″ area at the showerhead.
Getting comparable bids
- Write a one-page scope: rooms, bathroom fixtures, number of egress windows, ceiling type and flooring.
- Ask each contractor to price the permit, the water fix and any electrical panel work as separate lines.
- Ask whether quotes include design, dumpster and final cleaning.
- Compare per-square-foot totals only after removing the bathroom and egress lines, which do not scale with area.
- Check the license, insurance and recent permits of each contractor with your building department.
The usual order of work
| Phase | Who | Notes |
|---|---|---|
| 1. Water and radon | Waterproofer, mitigator | Test radon and fix leaks before anything is covered |
| 2. Permit and plan | Owner, designer | Rooms, egress windows, bathroom location |
| 3. Egress and drains | Excavator, plumber | Cut windows and break slab for drains while the space is open |
| 4. Framing and insulation | Carpenter | Foam on the concrete, treated bottom plates, fire blocking |
| 5. Rough electrical, plumbing, HVAC | Licensed trades | Inspections before walls close |
| 6. Drywall and ceiling | Drywall crew | Leave access panels for valves and cleanouts |
| 7. Flooring, trim, paint, fixtures | Finish trades or owner | Final inspection |
Bathroom and egress costs land early, in phase 3, which is why they surprise people who budget only by the square foot.
Common questions
How much does a basement bathroom cost?
Half baths run $5,000–$15,000 and full baths $15,000–$35,000 according to Fixr. A basement location adds risk of pumps and slab cutting.
Can you add a bathroom without breaking concrete?
Yes, with an upflush or macerating toilet that pumps waste up, or where the builder left rough-in drains in the slab.
Related calculators
Sources
- https://www.fixr.com/costs/bathroom-addition
- https://homeguide.com/costs/cost-to-put-bathroom-in-basement
- https://www.cityofboise.org/media/3924/434-irc-code-section-r305-ceiling-height.pdf