Boise, ID

Boise Plumbing Permit Cost

Boise plumbing permits price from the Plumbing Code Fee Schedule:

a new single-family home or duplex pays $130-$325 per dwelling unit by square footage, multi-fixture residential work pays a $32 base plus $12 per fixture, and commercial work pays a $32 base plus 2.28% of project value, stepping to 1.71% and 1.14% on large projects. Sewer and water service lines are $55 each.

Official fee scheduleVerified Sep 2026City of Boise — Planning & Development Services, Building Division

How this fee is calculated

These are the components the schedule defines for this permit, as they applied on 2026-09-28. A component only applies to your project if its conditions match — read that column before assuming a figure. Want a figure for your own project? Estimate this fee with the permit fee calculator.

Fee components for a plumbing permit
Component	Formula	Applies when	Range
NFPA 13D fire sprinkler service with backflow assembly ($12.00)Permit fee	`$12.00 flat fee`	fire sprinkler 13d is true	—
Sewer and water combination ($55.00)Permit fee	`$55.00 flat fee`	sewer water combo is true	—
Commercial plumbing $500,000-$1,000,000 ($11,410.88 + 1.71% over $500,000)Permit fee	`1.71% of project valuation above the first $500,000`	Occupancy is not residential and Project valuation at least $500,000 and Project valuation up to $1,000,000	—
Commercial plumbing over $1,000,000 ($19,969.04 + 1.14% over $1,000,000)Permit fee	`1.14% of project valuation above the first $1,000,000`	Occupancy is not residential and Project valuation over $1,000,000	—
Commercial plumbing under $500,000 (2.28% of value)Permit fee	`2.28% of project valuation`	Occupancy is not residential and Project valuation is provided and Project valuation under $500,000	—
Commercial plumbing base fee ($32.00)Permit fee	`$32.00 flat fee`	Occupancy is not residential and Project valuation is provided	—
Residential multi-fixture plumbing base fee ($32.00)Permit fee	`$32.00 flat fee`	residential fixtures is true and Fixtures at least 1	—
Plumbing fixtures and appliances ($12.00 each)Permit fee	`$12.00 per fixture`	residential fixtures is true and Fixtures at least 1	—
Residential lawn sprinkler supply through the backflow ($44.00)Permit fee	`$44.00 flat fee`	lawn sprinkler is true	—
New residential plumbing, up to 1,500 sq ft ($130 per dwelling unit)Permit fee	`$130.00 per dwelling unit`	new residential plumbing is true and Dwelling units at least 1 and Project area up to 1500	—
New residential plumbing, 1,501-2,500 sq ft ($180 per dwelling unit)Permit fee	`$180.00 per dwelling unit`	new residential plumbing is true and Dwelling units at least 1 and Project area up to 2500 and Project area over 1500	—
New residential plumbing, 2,501-3,500 sq ft ($250 per dwelling unit)Permit fee	`$250.00 per dwelling unit`	new residential plumbing is true and Dwelling units at least 1 and Project area up to 3500 and Project area over 2500	—
New residential plumbing, 3,501-4,500 sq ft ($290 per dwelling unit)Permit fee	`$290.00 per dwelling unit`	new residential plumbing is true and Dwelling units at least 1 and Project area up to 4500 and Project area over 3500	—
New residential plumbing, 4,501 sq ft and over ($325 per dwelling unit)Permit fee	`$325.00 per dwelling unit`	new residential plumbing is true and Dwelling units at least 1 and Project area over 4500	—
New residential plumbing over 4,501 sq ft ($65 per additional 1,000 sq ft or portion)Permit fee	`$65.00 per 1,000 sq ft of project area above 4,501 sq ft, or fraction thereof`	new residential plumbing is true and Project area over 4500	—
Plumbing re-inspection fee ($55.00)Inspection fee	`$55.00 per inspection`	reinspections at least 1	—
Water or waste re-piping ($80.00)Permit fee	`$80.00 flat fee`	repipe is true	—
Re-plumbing entire house or unit ($110.00)Permit fee	`$110.00 flat fee`	replumb house is true	—
Sewer service only ($55.00)Permit fee	`$55.00 flat fee`	sewer service only is true	—
Installation of a single fixture or appliance ($55.00)Permit fee	`$55.00 flat fee`	single fixture is true	—
Single sewer or water line replacement or new installation ($55.00)Permit fee	`$55.00 flat fee`	single line is true	—
Steam shower system including required backflow ($12.00)Permit fee	`$12.00 flat fee`	steam shower is true	—
Water service only ($55.00)Permit fee	`$55.00 flat fee`	water service only is true	—

A real permit fee is these components added together. The department’s final calculation is the one that applies — this is the schedule it will be based on.

A worked example

Follow the arithmetic by hand. Every line is produced by the engine from the rules above, so the total cannot drift away from the schedule behind it.

A remodel adding a bathroom in an existing Boise home: a $32-base multi-fixture permit covering 6 fixtures (toilet, sink, tub/shower, floor drain, dishwasher, water heater).

Inputs used for this example
Input	Value
Fixtures	6
Occupancy class	Residential
Type of work	Alteration
Residential fixtures	Yes

Example total

$104.00

An estimate, not an official fee. It is calculated from the published fee schedule as it applied on 2026-09-28. The permit office’s own calculation is the one that applies, and your project may fall under rules this schedule does not describe.

Fee schedule as of 2026-09-28Rules applied 2Rules considered 23

Fee components
Component	How it is calculated	Amount
Residential multi-fixture plumbing base fee ($32.00)Permit feePlumbing section B(2)(a): a $32.00 base permit fee shall be charged for residential projects with three or more dwelling units and any residential addition, alteration, repair, and/or fixture replacement, plus the Table B(2) fixture fees. Show the working Flat fee $32.00	`$32.00 flat fee`	$32.00
Plumbing fixtures and appliances ($12.00 each)Permit feePlumbing Table B(2): each fixture or appliance in the scope of work — $12.00 each (water closets, sinks, bathtubs/showers, bidets, clothes washers, dishwashers, floor drains, garbage disposals, laundry trays, water heaters, water softeners, sewage pumps, pressure relief valves, mobile home connections, sewer plugs and turnarounds, and similar). Show the working Number of fixtures 6 Rate per unit $12.00 Component total $72.00	`$12.00 per fixture`	$72.00
Total		$104.00

Fees that do not apply here

Listed so you can see what was considered and left out, rather than wondering whether something is missing. A rule can also be left out because it is not published for this permit at all, and that is stated where it matters.

NFPA 13D fire sprinkler service with backflow assembly ($12.00) — This fee does not apply to the inputs provided.
Sewer and water combination ($55.00) — This fee does not apply to the inputs provided.
Commercial plumbing $500,000-$1,000,000 ($11,410.88 + 1.71% over $500,000) — This fee does not apply to the inputs provided.
Commercial plumbing over $1,000,000 ($19,969.04 + 1.14% over $1,000,000) — This fee does not apply to the inputs provided.
Commercial plumbing under $500,000 (2.28% of value) — This fee does not apply to the inputs provided.
Commercial plumbing base fee ($32.00) — This fee does not apply to the inputs provided.
Residential lawn sprinkler supply through the backflow ($44.00) — This fee does not apply to the inputs provided.
New residential plumbing, up to 1,500 sq ft ($130 per dwelling unit) — This fee does not apply to the inputs provided.
New residential plumbing, 1,501-2,500 sq ft ($180 per dwelling unit) — This fee does not apply to the inputs provided.
New residential plumbing, 2,501-3,500 sq ft ($250 per dwelling unit) — This fee does not apply to the inputs provided.
New residential plumbing, 3,501-4,500 sq ft ($290 per dwelling unit) — This fee does not apply to the inputs provided.
New residential plumbing, 4,501 sq ft and over ($325 per dwelling unit) — This fee does not apply to the inputs provided.
New residential plumbing over 4,501 sq ft ($65 per additional 1,000 sq ft or portion) — This fee does not apply to the inputs provided.
Water or waste re-piping ($80.00) — This fee does not apply to the inputs provided.
Re-plumbing entire house or unit ($110.00) — This fee does not apply to the inputs provided.
Sewer service only ($55.00) — This fee does not apply to the inputs provided.
Installation of a single fixture or appliance ($55.00) — This fee does not apply to the inputs provided.
Single sewer or water line replacement or new installation ($55.00) — This fee does not apply to the inputs provided.
Steam shower system including required backflow ($12.00) — This fee does not apply to the inputs provided.
Water service only ($55.00) — This fee does not apply to the inputs provided.
Plumbing re-inspection fee ($55.00) — This fee does not apply to the inputs provided.

Assumptions

Calculated from 2 fee rules in effect on 2026-09-28.
Amounts are rounded to the nearest cent, once, at the end of each component.

Section B(2)(a): base permit $32.00. Table B(2): 6 fixtures × $12.00 = $72.00. Total: $104.00.

What is different in Boise

Plumbing permits are issued by Planning & Development Services; boilers, gas piping, hydronic heating and solar thermal ride on the mechanical permit instead. The new-home ladder covers everything in the unit; additions and remodels price per fixture at $12 each from a $32 base. Table B(1.a) add-ons — lawn sprinkler supply $44, NFPA 13D sprinkler service $12, steam shower $12 — join the base permit when the same contractor does the work.

What this figure does not include

Impact fees, utility connections and other departments’ permits are the usual omissions, and in some jurisdictions they are larger than the permit fee itself.

Not included in these figures

This estimate covers the plumbing permit only. It excludes:

Boilers, gas piping, hydronic and solar thermal work, which permits under the mechanical schedule.
Sewer, water and storm main extensions and connection fees from the utilities.
Commercial plan review and multi-discipline reviews.
Reinspections ($55) and after-hours inspection charges.
The special investigation fee for unpermitted work.

Common questions

How much is a plumbing permit for a new house in Boise?

$130 per dwelling unit up to 1,500 sq ft, $180 for 1,501-2,500, $250 for 2,501-3,500, $290 for 3,501-4,500, and $325 plus $65 per additional 1,000 sq ft or portion over 4,501 sq ft.

Boise City Plumbing Code Fee Schedule, Table B(1)

How are plumbing fixtures charged in Boise?

For residential projects with three or more units and any addition, alteration, repair or fixture replacement: a $32 base permit plus $12 per fixture or appliance — water closets, sinks, tubs and showers, water heaters, dishwashers, floor drains, disposals, wash basins, softeners and similar.

Boise City Plumbing Code Fee Schedule, B(2)(a-b) and Table B(2)

What does a water heater replacement permit cost in Boise?

A single fixture or appliance installation prices $55 under Table B(3); if the replacement is part of a multi-fixture permit the fixture charge is $12 with the $32 base. Residential tank-style water-heater replacement permits in Casper-style schedules do not apply here — Boise prices from its own tables.

Boise City Plumbing Code Fee Schedule, Table B(3)

How is commercial plumbing priced in Boise?

A $32 base plus a percentage of the project value (selling price of the completed installation): 2.28% under $500,000; $11,410.88 plus 1.71% of the value over $500,000 up to $1,000,000; $19,969.04 plus 1.14% of the value over $1,000,000.

Boise City Plumbing Code Fee Schedule, C(1)(a-b) and Table C(1)

What do sewer and water service line permits cost?

$55 each, or $55 for a sewer-and-water combination when only one inspection is required and the same contractor or homeowner performs the work (Table B(1.a) and the Table B(2) service rows).

Boise City Plumbing Code Fee Schedule, Table B(1.a)

How much is a lawn sprinkler permit in Boise?

Lawn sprinkler supply through the backflow is $44 within the base single-family permit (Table B(1.a)), and the per-fixture residential rate for sprinkler work under a multi-fixture permit is $12 per head or zone device with the $32 base.

Boise City Plumbing Code Fee Schedule, Table B(1.a)

What is re-plumbing an entire house in Boise?

$110 under Table B(3); water or waste re-piping alone is $80, and single fixture or single-line work is $55 each.

Boise City Plumbing Code Fee Schedule, Table B(3)

Do backflow devices cost extra in Boise?

A backflow assembly with an NFPA 13D fire sprinkler service is $12 within the base permit, and each backflow preventer in a multi-fixture scope prices at the $12 fixture rate with the $32 base.

Boise City Plumbing Code Fee Schedule, Table B(1.a) and Table B(2)

Source and verification

The documents behind every figure on this page, with the dates that make them checkable.

Fee schedule (PDF)CityPrimary source
Boise City Plumbing Code Fee Schedule (current edition, 10-1-2021)
City of Boise, Planning & Development Services · Document dated October 1, 2021 · Effective October 1, 2021 · Retrieved September 26, 2026
Tables B(1) (new SFD/duplex per dwelling unit $130-$325 + $65 per 1,000 over 4,501), B(1.a) (add-ons: 13D sprinkler $12, lawn sprinkler $44, sewer/water service $55), B(2) ($32 base + $12 per fixture), B(3) (misc $55-$110), C(1) (commercial $32 base + 2.28% / $11,410.88 + 1.71% / $19,969.04 + 1.14%).

Verification

Last verified against the official source in Sep 2026.