How Old Is the Plumbing? Housing Age in Phoenix and the Valley, by City and Neighborhood
The year a Valley home was built is the best single clue to what is inside its walls and under its slab. This page shows when the homes in 16 cities and towns and 20 Phoenix ZIP codes were built, grouped by the pipe materials that were common in each period, using the latest U.S. Census data available as of September 2026, which covers 2020 to 2024.
42%
of Phoenix's 653,065 homes were built before 1980, which is 271,459 homes
Sun City
has the oldest housing of any city here, with 89% built before 1980
85007
(Downtown west and Encanto south) has the most homes from before 1960 of any Phoenix ZIP code shown, at 50%
405,793
homes across these cities date from 1980 to 1999, the period that includes the polybutylene years
What each period usually means for plumbing
Before 1960.
Galvanized steel water lines and cast iron drains. Galvanized pipe rusts shut from the inside, which shows up as low pressure and brown water. Some sewer lines from this period are Orangeburg, a tar and fiber pipe that flattens with age.
1960 to 1979.
Copper water lines, very often run under the concrete slab. This is the slab leak period. Drains are cast iron or early ABS plastic.
1980 to 1999.
A mix of copper and plastic. Polybutylene was installed from about 1978 to 1995 and is the material most likely to fail without warning. Not every home from these years has it.
2000 and later.
PEX and copper supply lines with ABS or PVC drains. The pipe is usually sound. Hard water damage to water heaters, valves and fixtures is the main issue.
Share of homes built before 1980
Larger and darker circles mean older housing. Click any circle for the full breakdown.
Every city and neighborhood, latest Census data as of 2026
Sort any column by clicking its heading. The bar shows all four periods at once, oldest on the left.
Source: U.S. Census Bureau, American Community Survey 2020 to 2024 five year estimates, table B25034, Year Structure Built, retrieved September 20, 2026 through Census Reporter. Every row was checked by adding the ten Census year groups and confirming they equal the published total. Counts are housing units of every type, including apartments and condos. These are survey estimates with a margin of error, which is larger for small places such as Carefree, Cave Creek and Litchfield Park. Sun City, Sun City West and Anthem are census designated places. Phoenix neighborhood rows are ZIP code tabulation areas. Map positions are approximate centers, not Census boundaries. Pipe material periods describe common Arizona building practice and are not part of the Census data.
What to do with this if you own one of these homes
If your home dates from before 1980 and still has its original water lines, the question is when, not whether, they will need attention. A pressure test and a look at the exposed pipe tells us most of what we need to know. If you have had one slab leak, a second is likely, and rerouting the lines overhead through the attic usually costs less over time than chasing leaks under the floor one at a time.
If your home dates from 1980 to 1999, check for gray polybutylene pipe at the water heater and under the sinks. If it is there, plan the repipe on your schedule instead of the pipe's. If you are buying a home from any of these periods, a sewer camera inspection before closing is inexpensive next to the cost of replacing a collapsed line afterward.
Questions about this data
No. The Census records when homes were built, not what they were plumbed with. The bands on this page line up with the years each pipe material was common in the Valley, so they show likelihood, not certainty. Many older homes have already been repiped, and some newer homes were built with materials that later failed. The only way to know is to look: at the water heater connections, under sinks, at the main shutoff and in the attic.
The Census reports homes by decade, so any finer cut would be an estimate. Copper run under the slab was the norm from about 1960 through the late 1970s. Polybutylene was installed from about 1978 to 1995, which falls mostly inside the 1980 to 1999 band but also touches the end of the 1970s. We chose to show the real Census counts and explain the overlap instead of printing estimated numbers.
Not necessarily. Polybutylene was one of several materials used in those years, alongside copper and later CPVC and PEX. It is gray, flexible, usually stamped PB2110, and most often visible at the water heater, under sinks and where the main line enters the home. If you find it, plan a repipe before it fails, because the fittings and the pipe wall both degrade from the inside where you cannot see it.
The Census does not publish figures for Phoenix urban villages or named neighborhoods. ZIP code tabulation areas are the closest published geography, so each Phoenix row is one ZIP code labeled with the neighborhood it is best known for. ZIP code lines do not match village lines exactly.
Most Valley homes sit on a concrete slab with no basement or crawl space. From about 1960 into the late 1970s, copper water lines were routinely run under or through that slab. Decades of hard water, soil movement and contact with concrete wear the copper thin until it leaks where nobody can see it. Warm spots on the floor, the sound of running water with everything off, and a water bill that climbs for no reason are the usual signs.
It is the newest available as of September 2026. The Census Bureau releases these five year estimates once a year, each December. The set used here covers surveys taken from 2020 through 2024. The next release is due in December 2026, and because housing age changes slowly, the shares will move only slightly.
Yes. It is drawn from public Census data. You are welcome to cite it or link to this page, and a CSV download is provided below the table.
For information purposes only. This page is a general guide compiled from public sources as of September 2026. It is not professional, legal, financial or engineering advice, and it is not a quote or a guarantee. Census data shows when homes were built, not what pipe is inside any particular home. Only an inspection can tell you that. Figures, rules and programs change, and your own home, bill or project may differ. Confirm anything important with the source linked on this page or with the agency or utility concerned before you act on it. American Discount Plumbing accepts no liability for decisions made using this page.
Not sure what your home is plumbed with?
American Discount Plumbing has worked on Valley homes from every one of these periods since 2000. Owner Pavel Farcas looks at the job himself and tells you what he finds, whether that is a full repipe or nothing at all. Licensed, bonded and insured, AZ ROC #150707.
Related: slab leak repair, leak detection, sewer line replacement, what a leak costs per month in each city, water hardness by city.
