Repipe cost is driven by your home's square footage, number of bathrooms and fixtures, how many stories it has, whether pipes run through a slab, attic, or crawlspace, and drywall repair after. Both PEX and copper are code-approved; PEX installs faster and resists freeze damage, while copper lasts longer and is recyclable.
What actually drives the cost of a repipe?
Cost tracks the amount of pipe, the number of connections, and how hard the pipes are to reach. A small single-story home with one bathroom needs far less pipe and fewer fittings than a two-story home with three full baths, a kitchen, a laundry, and outdoor spigots. More fixtures mean more tie-in points, and each connection adds labor.
Access is the next big lever. When supply lines run through an attic or an open crawlspace, a plumber can often reroute new lines overhead or underneath with limited wall opening. When the original pipe is buried in a slab foundation, the common fix is to abandon the slab lines and run new pipe through the attic and down the walls, which changes the labor mix. Number of stories matters too, since vertical runs between floors take more time and more drops into wall cavities.
The part many homeowners overlook is finish repair. To reach pipes, a crew cuts access holes in drywall, and sometimes tile or stucco. Patching, texturing, and repainting those openings is a separate trade and a real cost. A home with simple painted drywall is cheaper to close up than one with custom tile walls or plaster.
If you want a sense of scale, national home-improvement surveys put a typical whole-house repipe in the low-to-mid four figures up to the low five figures. Treat that only as a rough national estimate, not a quote. Your real number depends on the factors above, and the only honest figure is a written estimate after someone walks your home. In hard-water areas like Phoenix, corrosion and scale build up faster, so an aging system may justify a full repipe sooner than the same pipe would elsewhere.
PEX vs copper: a side-by-side comparison
Both materials are listed in the model plumbing codes and accepted for potable water supply. The table below compares the traits that matter most for a repipe.
| Trait | PEX | Copper |
|---|---|---|
| Flexibility | Bends around corners; fewer fittings | Rigid; needs elbows at every turn |
| Typical install time | About 1 to 2 days for many homes | About 3 to 5 days for many homes |
| Fittings | Crimp, clamp, or expansion fittings | Soldered (sweated) or press joints |
| Freeze behavior | Expands under ice, so it resists bursting | Splits when water freezes and expands |
| Corrosion risk | Not subject to pinhole corrosion | Can develop pinhole leaks over time |
| Lifespan | Several decades when installed to spec | Often 50-plus years |
| Recyclability | Limited; not widely recycled | Fully recyclable scrap metal |
| Material cost | Lower material and labor | Higher material and labor |
The freeze line is worth a closer look. The Department of Energy notes that "southern states" generally start having frozen-pipe problems when the temperature reaches about 20 degrees Fahrenheit, so even Phoenix sees risk during a hard cold snap at hose bibs and attic runs. Because PEX can expand as water turns to ice, it is more forgiving in those conditions, while copper is more likely to split. Neither material should be left to freeze, but PEX buys a margin.
Both are code-approved, so why is PEX now so common?
Acceptance of both materials is settled. Copper has been a standard for generations and remains a code-listed option. PEX is recognized by the Plastics Pipe Institute and accepted in the International Plumbing Code (IPC) and the Uniform Plumbing Code (UPC), the two model codes that Arizona jurisdictions adopt. So a repipe in either material can pass inspection when installed correctly.
PEX took over much of the residential market for practical reasons. It ships in long flexible coils, so a plumber can run a single line from a central manifold to a fixture with few or no joints in the wall. Fewer joints means fewer points that can leak. It installs faster, which lowers labor, and it tolerates the freeze-thaw cycle better. The Plastics Pipe Institute describes PEX as offering "flexibility, durability, and ease of installation," which sums up why it displaced rigid pipe in so many new homes and repipes.
Copper still earns its place. It is recyclable, it handles high heat without question, and many homeowners simply trust a metal pipe they can see. Some also prefer it where pipe will be exposed rather than hidden in walls. The trade-off is cost and the slow risk of pinhole leaks, especially in aggressive water.
There is one health note that applies to neither PEX nor new copper but to what they replace. The EPA states that lead can enter drinking water from "lead solder used to join copper pipes," which was common before the 1986 lead-solder ban, and from older galvanized pipe where "lead particles can attach to the surface." A modern repipe in PEX or lead-free copper removes that legacy concern.
What are the signs you need a repipe?
A repipe is a big job, so it is reserved for whole-system problems, not a single bad fixture. Watch for these patterns:
- Repeat pinhole leaks. One leak is a repair. Several leaks across the house in a year point to pipe at the end of its life.
- Rusty or discolored water, especially at first draw in the morning, which suggests internal corrosion.
- Low pressure everywhere, caused by scale and rust narrowing the pipe walls over time.
- Known problem materials. Gray polybutylene (installed roughly 1978 to mid-1995) and old galvanized steel are widely recommended for replacement regardless of current condition.
The cost of leaks is not small. EPA WaterSense reports that household leaks waste "nearly 1 trillion gallons" of water nationally each year, and the average home loses more than 9,300 gallons annually. A failing system quietly adds to that. For deeper detail on each warning sign, see our pages on the signs of old, failing pipes, whether you should replace polybutylene pipes, and common galvanized pipe problems.
How should you decide between PEX and copper?
Start with the problem you are solving, then match the material to it. If your goal is the lowest cost and fastest job, and your pipe runs are accessible through an attic or crawlspace, PEX is usually the practical pick. It cuts labor days, reduces in-wall joints, and tolerates a cold snap better, which matters for the exterior and attic lines that freeze first in Phoenix.
If you value the longest service life and recyclable material, plan to keep the home for decades, or want exposed pipe in a mechanical room or garage, copper is a sound choice. Be ready for more labor days and a higher material cost, and know that copper can still develop pinhole leaks in aggressive water.
For most homeowners the deciding factors are budget, how long you plan to stay, and how your pipes are routed. Get a written estimate that spells out the material, the number of fixtures, the access method, and the drywall repair plan, because that last line item is where surprises hide. A licensed plumber should walk the home, confirm the existing pipe material, and quote the full scope before any wall is opened. With both PEX and copper accepted by code, you are choosing on cost, longevity, and freeze tolerance, not on whether the work will pass inspection.