Cost to Basement Bathroom Addition in Boise, ID (2026)
If you’re budgeting a basement bathroom addition in Boise, most projects run $6,630-$18,942, 5% below the $12,500 national average. What moves that number most is usually one thing: Below-Slab vs. Macerating System. On its own it can swing the cost by $2,000 - $8,000, so that’s the decision to slow down on before you sweat the smaller stuff.
Easiest place to save: Start with a half bath (toilet and sink) instead of a full bath - you get 70% of the functionality at 50% of the cost.
$6,630-$18,942 in Boise
5% below the national average · 0.95x cost multiplier
Expect to pay $6,630-$18,942 for a basement bathroom addition in Boise, about 5% below the national benchmark. The Mountain West region's contractor market and material costs account for most of this difference. The detailed breakdown below shows how budget, mid-range, and premium projects compare at Boise prices.
Cost Breakdown in Boise
| Line Item | Low | Mid | High |
|---|---|---|---|
| Cost per bathroom | $4262 | $11839 | $23678 |
| Materials | $2,870 | $6,150 | $14,350 |
| Labor | $3,435 | $6,440 | $10,304 |
| Permits | $615 | $820 | $1,025 |
| Total | $6,920-6% vs. national avg | $13,410-6% vs. national avg | $27,216-5% vs. national avg |
Budget
Half bath (toilet and sink) added to unfinished basement near existing stack. Basic fixtures, standard tile, and minimal framing.
Mid-Range
Full 3-piece bath (toilet, sink, shower) with below-slab ejector or macerating toilet system, mid-range tile, standard vanity, and proper ventilation.
Premium
Full bath with tile shower, premium fixtures, custom vanity, below-slab plumbing with ejector pump, heated floor, and full exhaust ventilation system.
Material Options
Material prices below are national averages; availability in Boise may shift costs slightly.
| Material | Cost/Unit | Best For |
|---|---|---|
| Macerating (Upflush) Toilet System | $700-$1,800 unit only | Budget basement bathroom additions, retrofit situationsNo concrete breaking required, lower upfront cost, relocatable |
| Below-Slab Ejector Pump System | $1,500-$4,000 for pump and pit only | Long-term reliable basement bathrooms, high-use situationsCode-compliant everywhere, gravity-fed to pump, quieter |
| Standard Ceramic Tile | $3-$10/sq ft materials only | Budget to mid-range basement bathroomsAffordable, durable, waterproof, wide selection |
| Luxury Vinyl Tile (LVT) | $3-$8/sq ft materials only | Budget installs, DIY-friendly flooringWarm underfoot, waterproof, easy DIY install |
| Porcelain Tile (Floor and Shower) | $6-$25/sq ft materials only | Premium basement bathrooms, shower surroundsMost durable, low water absorption, premium look |
Other Projects in Boise
Boise Estimate
Typical Range
$6,630-$18,942
vs. National Average
5% below national
Cost Multiplier
0.95x
Cost Per bathroom
$4262-$23678
This 0.95x estimate prices Boise labor from BLS Occupational Employment and Wage Statistics (May 2025) and applies a lighter regional adjustment to materials and permits, which vary less by metro than labor does. Actual bids vary by contractor, project scope, and timing.
See national average costs →