# Repiping Doubles and Duplexes in Columbus

> Repiping Columbus doubles and 2 to 3 unit houses: tracing which half each line feeds, shared or separate mains, the party wall, both households on water.

URL: https://slaterepipingcolumbus.com/double-repiping/

Repipes for Columbus doubles, duplexes and two and three unit houses, with each household's lines traced, the shared main sorted out and the water kept on for both sides.

Last Updated: October 29, 2026

Repipes for Columbus doubles, duplexes and two and three unit houses, with each household's lines traced, the shared main sorted out and the water kept on for both sides.

Last Updated: October 29, 2026

**21.4%** Homes in the 43202 ZIP in buildings of two to four units, against 12.6% for Columbus as a whole

**1,165** Duplex-style dwelling records in the 43206 ZIP on the County Auditor's files, the most of any ZIP checked

**$275** City of Columbus plumbing permit for a 1, 2 or 3 family building, two inspections included

The double is a Columbus fixture: two households side by side under one roof, sharing a party wall and, quite often, more plumbing than either of them knows. [Slate Repiping Columbus](https://slaterepipingcolumbus.com/) offers repiping for doubles, duplexes and two and three unit houses across Columbus and nearby Franklin County communities. The work is carried out by licensed and insured plumbing contractors under the plumbing permit for the building.

These buildings are concentrated in the older neighborhoods. Roughly one in five homes in the 43201, 43202, 43205 and 43206 ZIPs sits in a building of two to four units, by Census Bureau count, against 12.6% for the city. The County Auditor’s files list more than a thousand duplex-style dwellings each in 43201, 43202 and 43206. Most were built when [galvanized pipe](https://slaterepipingcolumbus.com/galvanized-pipe-replacement/) was standard, so a double repipe is usually an [old house repipe](https://slaterepipingcolumbus.com/old-house-repiping/) with a second household added. Buildings of four or more units belong on the [commercial and multi-unit repiping](https://slaterepipingcolumbus.com/commercial-repiping/) page instead.

In practice that means doubles in [German Village](https://slaterepipingcolumbus.com/service-areas/german-village/) and Schumacher Place, in south [Clintonville](https://slaterepipingcolumbus.com/service-areas/clintonville/) and Old North Columbus, around Olde Towne East, and on parts of the [Hilltop](https://slaterepipingcolumbus.com/service-areas/hilltop/). The pipe in each is similar to a single-family house of the same age. What changes is that two kitchens, two or more bathrooms and two laundries hang off a system that may have been laid out for one family and split later, and that two households live with the schedule.

## Which half does each line feed?

The first visit in a double is mostly tracing. Some doubles have two service lines, two meters and two mains, so each half is its own system. Others have one service line and one meter, with a main that branches to both sides. Many fall in between: two meters, but a cold line that crosses the party wall to feed a fixture on the other side, or a laundry tied into the neighbor’s main during a long-ago repair.

The walk-through starts at each meter, follows each main and marks which fixtures it reaches, then checks the result by shutting a valve and seeing what goes dry. It also records each unit’s water heater, because two heaters on one main share the same flow, and measures pressure and flow at the top fixtures of each side.

## One main or two

Where each half has its own meter and main, each can be repiped as its own system, now or later. Where the halves share one main, the new main is sized for both units’ fixtures, and a shutoff is added for each side so one household’s leak does not shut off the other. Ohio’s rule calling for a shutoff for each unit is written for buildings larger than three units, but in a double it is still one of the most useful things a repipe can add.

The buried service line is a separate question. Inside Columbus, the City’s lead and galvanized line program replaces service lines street by street, and only the owner listed with the Franklin County Auditor can sign the work agreement for the building. Where one service line feeds both halves, both sides depend on it. The [Columbus lead service line program guide](https://slaterepipingcolumbus.com/guide/columbus-lead-service-line-program/) explains how that work and an interior repipe can be scheduled around each other.

## Crossing the party wall

The party wall between the halves of a Columbus double may be brick or framing. Old lines sometimes pass through it, and any new pipe that crosses it has to restore the fire separation around the penetration. Where practical, the new layout keeps each unit’s pipe on its own side, so a future repair to one half does not mean opening the other.

When only one half is repiped, any old line that crosses into it from the other side is either replaced or capped. Otherwise the new side can keep drawing water through old galvanized pipe, and the owner pays for a repipe that still delivers rusty water to one fixture.

## Keeping both households on water

A double repipe is planned so that neither household goes a night without water. New lines are run while the old ones still serve both sides. Each unit is then cut over on its own, usually one fixture group at a time, and a shared main is switched once at a set time. Both households get the schedule in writing beforehand: which days, roughly how long the water is off and which rooms have open walls. The [guide to how long a repipe takes](https://slaterepipingcolumbus.com/guide/how-long-does-repiping-take/) covers typical timing.

Access is the other part. In a double, the upstairs bath on one side may only be reachable from a closet on the other, or the basement may be split by a wall with one door. The scope says which rooms in each unit need to be cleared and when.

## Three-unit houses and stacked flats

A three-unit house, whether a converted single-family or a building with a flat on each floor, falls under the same 1, 2 or 3 family code and permit as a double. The plumbing is usually stacked: risers carry water from the basement main up through each unit to the one above. Replacing a riser affects every unit it passes through, so stacked flats are often repiped together, with one floor’s walls opened at a time.

## Permit, testing and price

Under the Residential Code of Ohio, the Ohio Plumbing Code governs 1, 2 and 3 family dwellings, so a double or triplex takes the City of Columbus residential plumbing permit: $275 with two inspections. The City issues homeowner permits only for single-family homes the owner occupies, so a double needs a State-licensed, City-registered contractor even when the owner lives in one half. In suburbs that contract with Franklin County Public Health, the city issues the permit and the County reviews the plan, with a fixture count that has to match. The [Columbus repiping permit guide](https://slaterepipingcolumbus.com/guide/repiping-permit-columbus/) covers the details.

Each unit’s new piping is pressure tested and flushed before its walls close, and every shutoff is labeled with the unit it serves. There is no published Columbus price range for a double. It is driven by the fixture count of both units, how much of the main is shared, the climb to upper floors and the patching; the [repipe cost guide](https://slaterepipingcolumbus.com/guide/repiping-cost/) explains each driver, and the [whole-house repiping](https://slaterepipingcolumbus.com/whole-house-repiping/) page describes what each unit’s system includes.

## What's included

- A map of which meter, main and branch serves each unit
- A shutoff for each unit where the lines allow one
- New hot and cold supply in PEX or copper for the units in the scope
- Lines that cross the party wall rerouted or replaced so each unit's pipe stays on its own side where practical
- A shutoff schedule given to both households before work starts
- Reconnection of each unit's water heater, fixtures and laundry
- Pressure test and flush for each unit, labeled shutoffs, permit and inspections

## Repiping both halves of a double together or one at a time

|  | One half now | Both halves together |
| --- | --- | --- |
| Permit | A permit for the work done now, another later | One job under the 1, 2 or 3 family permit |
| Shared main | Has to be split or left feeding both sides | Replaced once, with a shutoff for each side |
| Lines across the party wall | Old pipe may keep feeding the new side | Sorted out once |
| Water off | Only the half being worked on, plus the shared main at cutover | Both households, staged so neither is without water overnight |
| Where it fits | Separate meters and mains, or one side clearly worse | Shared main, crossing lines, or both sides on the same old pipe |

## Related resources

- Learn [How does repiping a house work?](https://slaterepipingcolumbus.com/guide/repiping-guide/)The whole picture in one place: what the water supply system is, why galvanized and older copper give out, how a repipe is scoped, permitted, installed and tested in Columbus, and what to ask before agreeing to one.
- Learn [Do you need a permit to repipe a house in Columbus?](https://slaterepipingcolumbus.com/guide/repiping-permit-columbus/)Which office issues the permit for your address, who is allowed to pull it, what it costs, what changed with county plan review in February 2026, and what happens when a repipe is done without one.
- Learn [How does the Columbus lead service line replacement program work?](https://slaterepipingcolumbus.com/guide/columbus-lead-service-line-program/)What the City replaces, when it reaches a street, who has to sign, how to check an address on the map, and how to time an interior repipe so the house is opened once.
- Learn [How long does it take to repipe a house?](https://slaterepipingcolumbus.com/guide/how-long-does-repiping-take/)A repipe is measured in days, not weeks, but the number depends on the house. Here is what stretches or shortens the schedule, how the water stays on in stages, and where the inspection and the patching fit.
- Cost Guide [How much does it cost to repipe a house in Columbus?](https://slaterepipingcolumbus.com/guide/repiping-cost/)Typical Columbus-area ranges for a whole-house repipe in PEX or copper, what sits inside the price, the permit fees by office, and why two quotes for the same house can differ.

## How a repipe runs

1. First call Describe the houseIts age, the pipe you can see in the basement, the leaks so far and which floors lose pressure.
2. Walk through Map and scopeMains, branches, shutoffs and fixtures traced from the meter; material, openings and permit agreed in writing.
3. Pipe day Replace and reconnectWater shut off in stages, new lines run, fixtures and the water heater reconnected.
4. Sign off Test, inspect, patchPressure test and flush, permit inspections, then the openings are closed.

## What this work looks like

Two water meters side by side on a white basement wall, each with a new shutoff valve after it, in a Columbus house

Red PEX pipe passing through a hole in an old brick basement wall, sealed with red fire-stop sealant, in a Columbus house

Two water heaters side by side against a white basement wall, each with its own supply lines, in a Columbus house

Shutoff valve and brass transition fitting where new red PEX meets older copper in a basement ceiling, blue tape on the joist, in a Columbus house

## Double and duplex repiping questions

### Which plumbing permit does a Columbus double fall under?

A double, duplex or three-unit house is a 1, 2 or 3 family dwelling, so inside Columbus it takes the City's residential plumbing permit, $275 with two inspections. A building of four or more units moves to the multi-family and commercial permit, which is $550 with one inspection or $700 with two.

### Can the owner of a double pull the plumbing permit for a repipe?

Not inside Columbus. The City issues homeowner plumbing permits only for an existing single-family home the owner lives in. A double needs a permit pulled by a plumbing contractor licensed by the State of Ohio and registered with the City, even if the owner lives in one half.

### Do both households lose water at the same time during a double repipe?

Only briefly, if the work is staged. New lines are run while the old ones still serve both units, and each unit is switched over on its own. Where the halves share a main, that main has to be cut over once, and the schedule should tell both households when.

### Should each half of a double have its own water shutoff?

It is worth having. Without separate shutoffs, a leak in one unit means turning off water to both. Where each half already has its own meter and main, a shutoff is added at each; where the halves share a main, a repipe is the time to split it so each side can be isolated.

## Related services

### Whole-house repiping

Every hot and cold supply line from the main shutoff to the fixtures, replaced in PEX or copper, pressure tested and inspected under a City or suburban plumbing permit.

### Old house repiping

Repiping planned for prewar houses: routes through basements, closets and chases, openings in plaster kept few and listed, and the old valves and fittings brought up to date.

### Commercial and multi-unit repiping

Water supply replacement in buildings of four or more units and small commercial spaces, with risers, unit shutoffs, plan review and the schedule for the people inside planned together.