Peoria Tub-to-Shower Conversions by the Numbers

Last reviewed 2026-07-25. Journalists, researchers, and community groups are welcome to cite any figure on this page with attribution and a link.

Everything on this page is a published figure with a link to the document it came from. No estimates, no averages of our own making, nothing carried in from another market. The four topics are the ones that actually govern a tub-to-shower conversion in Peoria and the West Valley communities around it: what Arizona requires of whoever is paid to do the work, which contractor classifications cover it, what the water is doing to the surfaces, and what dimensions the federal accessibility standards specify.

Two cautions before the tables. Hardness ranges move within a year and across a service area, so treat the figure for your district as a range rather than a constant, and read the report covering your own address. And the accessibility dimensions here come from the ADA Standards, which are written for facilities covered by the Americans with Disabilities Act rather than for private single-family houses. There is no ADA permit for a home and no certification that attaches to one. The dimensions are useful as a reference, nothing more.

What Arizona requires before anyone can be paid for this work

Arizona Revised Statutes 32-1121 lists who is exempt from contractor licensing, and the exemption homeowners hear about most is narrower than its reputation. Paragraph (A)(14) exempts a person other than a licensed contractor on one undertaking or project by one or more contracts for which the aggregate contract price, including labor, materials and all other items, is less than $1,000. The statute then adds that the work or operations exempt under this paragraph shall be of a casual or minor nature. A bathroom whose plumbing is being altered is rarely either of those things.

Three carve-outs in the same paragraph do most of the work. The exemption does not apply in any case in which the performance of the work requires a local building permit. It does not apply where the work is part of a larger operation, including a project divided into contracts of less than $1,000 for the purpose of evasion. And it does not apply to a person who advertises without including the words not a licensed contractor. Taken together, those three sentences pull most shower conversions out of the exemption in most jurisdictions around Peoria.

Which Registrar of Contractors classifications cover a shower conversion

The Arizona Registrar of Contractors publishes its license classifications with the scope of each one, and more than one can legitimately cover a tub-to-shower conversion depending on the work and the price. Two of the residential remodeling classifications carry published dollar ceilings on project size, which is unusual and worth knowing when quotes come in at different numbers. The plumbing and general remodeling classifications carry no published ceiling. The useful step for a homeowner is not memorizing the list, it is confirming that the classification held actually covers the scope being quoted.

Published water hardness, district by district

These are the 2024 figures from each utility's own water quality report, with the public water system ID where the report carries one. They are printed as ranges because they are ranges: a district can draw on several wells with different chemistry, and the figure at one address is not the figure at another. Hardness is not a regulated contaminant, so it appears in these reports among the unregulated substances utilities monitor and publish rather than among the ones carrying enforceable limits.

The dimensions in the ADA Standards, and where they apply

The ADA Standards govern facilities covered by the Americans with Disabilities Act. A private single-family house is not one of them, so nothing in this table is a code requirement for your bathroom and no home shower can be certified against it. What the figures are good for is a reference. They are the dimensions the U.S. Access Board publishes in its guide to bathing rooms, and they describe compartments, thresholds and grab bars sized around real equipment and real reach. Your local building code, not the ADA, is what a permit inspection is measured against.

Who lives in the houses these bathrooms are in

Population below is the 2020 Census count. The age and tenure shares are the figures the Census Bureau publishes on each place's QuickFacts profile. The spread is the point. Two of these places are age-restricted communities where residents 65 and over run past seven in ten, one is a city where more than a quarter of residents are under 18, and the core city sits between them with a 2025 population estimate of 200,881 against 190,985 in 2020. A request from Sun City West and a request from El Mirage are usually coming from very different households.

Sources & Methodology

Every figure above was taken from the primary sources below (accessed 2026-07-25). Where a number is derived (arithmetic on published figures) or covers a broader period or area, the text says so.

1. Arizona Revised Statutes 32-1121, exemptions from contractor licensing — The $1,000 aggregate contract price threshold, the casual or minor nature test, and the three exceptions covering local building permits, larger operations and advertising.
2. Arizona Registrar of Contractors license classifications — Published scope and dollar limits for R-62 Minor Home Improvements, R-61 Carpentry Remodeling and Repairs, B-3 General Remodeling and Repair, and R-37 Plumbing Including Solar.
3. EPCOR Water Arizona - Sun City 2024 water quality report — System AZ0407099, hardness of 7 to 12 grains per gallon, total dissolved solids 221 to 359 ppm, nearly 24,000 connections, and West Salt River Valley Sub-Basin groundwater serving Sun City and Youngtown.
4. EPCOR Water Arizona - Sun City West 2024 water quality report — System AZ0407150, hardness of 4 to 12 grains per gallon, total dissolved solids 340 to 356 ppm, and roughly 15,600 connections.
5. EPCOR Water Arizona - Agua Fria 2024 water quality report — System AZ0407695, hardness of 2 to 17 grains per gallon and total dissolved solids of 190 to 638 ppm across parts of multiple West Valley cities and towns.
6. EPCOR Water Arizona - Northeast Agua Fria 2024 water quality report — System AZ0407531, hardness of 12 to 15 grains per gallon and total dissolved solids of 374 to 461 ppm.
7. City of El Mirage 2024 water quality report — Nine city wells, hardness varying by well across a range of 4 to 9 grains averaging 7, and the statement that 7.5 grains is recommended for water softeners.
8. U.S. Access Board - Chapter 6: Bathing Rooms, Guide to the ADA Standards — Transfer and roll-in compartment sizes, the half-inch threshold maximum and 1:2 bevel, and grab bar height, diameter and wall clearance.
9. U.S. Census Bureau QuickFacts - Sun City CDP, Arizona — 2020 population of 39,931, 74.7 percent aged 65 and over, 1.3 percent under 18, and an owner-occupied housing rate of 84.2 percent.
10. U.S. Census Bureau QuickFacts - Sun City West CDP, Arizona — 2020 population of 25,806, 85.0 percent aged 65 and over, 0.3 percent under 18, and an owner-occupied housing rate of 88.1 percent.
11. U.S. Census Bureau QuickFacts - Peoria city, Arizona — 2020 population of 190,985, a 2025 estimate of 200,881, 19.6 percent aged 65 and over and an owner-occupied housing rate of 76.0 percent.
12. U.S. Census Bureau QuickFacts - El Mirage city, Arizona — 2020 population of 35,805, 10.1 percent aged 65 and over, 27.7 percent under 18, and an owner-occupied housing rate of 69.7 percent.
13. U.S. Census Bureau QuickFacts - Youngtown town, Arizona — 2020 population of 7,056, a 2025 estimate of 7,039, 18.1 percent aged 65 and over and an owner-occupied housing rate of 64.1 percent.
14. U.S. Geological Survey - Hardness of Water — The definition of hardness, the soft to very hard classification bands in milligrams per liter, soap scum formation and calcium carbonate scale in heated systems.
15. Maricopa County - Ordinances, Regulations and Codes — The August 17, 2022 adoption of the 2018 International Building, Residential, Plumbing, Mechanical, Fuel Gas and Existing Building Codes and the 2017 National Electrical Code.
16. Town of Youngtown - Construction Codes and Licensing — The 2021 I-Code adoptions, the 2020 National Electrical Code, and the requirement that contractors hold both an Arizona ROC license and a Town of Youngtown business license.