# Partial Repiping in Chicago

> Partial repipe in Chicago: one bathroom, riser, hot side or floor, every transition to old pipe disclosed, and when partial is a poor bet. Ask what fits.

URL: https://chicagolakerepiping.com/partial-repiping/

A partial repipe replaces a defined part of the supply piping, such as one bathroom, one riser, the hot side or one floor, with every joint to the pipe that stays named on the quote.

Last Updated: October 25, 2026

**$150** City of Chicago Express plumbing permit per dwelling unit, plus $150 per unit served when risers are replaced

**Association letter** Required for a Chicago Express permit on condominium property, even inside a single unit

**Full-riser drawing** Riser work under a Chicago Express permit needs a diagram of the whole riser showing size and material

**January 2023** Since then, Illinois law has barred partial replacement of lead service lines

A partial repipe in Chicago replaces a defined part of the water supply piping and leaves the rest in service. [Chicago Lake Repiping](https://chicagolakerepiping.com/) manages partial repipes in houses, two-flats and condo units across Chicago and nearby Cook County suburbs: one bathroom’s branches, one riser, the hot side only, or one floor. Licensed and insured plumbing contractors do the work. A partial job is only as good as its boundary, so this page is mainly about where that boundary goes and what sits on the other side of it.

The words matter here. After a partial repipe, the building still has old pipe, and some of it still feeds the new pipe. A quote, a listing or a conversation with a buyer should never describe it as repiped. The [whole-house repiping](https://chicagolakerepiping.com/whole-house-repiping/) page covers the full version, and the [guide to galvanized pipes in Chicago homes](https://chicagolakerepiping.com/guide/galvanized-pipes-chicago-homes/) explains how steel systems age.

## Where the boundary goes

There are four shapes a partial repipe can take, and each puts its edges in a different place.

**One bathroom.** The branches from the riser or trunk to that room’s sink, toilet and tub or shower are replaced. The boundary is the tee where the branch leaves the riser. This is the shape a remodel produces, because the walls are already open.

**One riser.** A riser is the vertical pipe that feeds fixtures stacked above one another. Replacing one riser means new pipe from its base at the basement main to its top, and its branches where agreed. In a Chicago building, riser work under an Express permit needs a contractor’s drawing of the entire riser showing its size and material, and the permit fee rises by $150 per dwelling unit the riser serves. The [riser replacement](https://chicagolakerepiping.com/riser-replacement/) page covers multi-story stacks.

**Hot side only.** Hot water distribution from the water heater out to the fixtures is replaced, and the cold side stays. Warm water speeds corrosion in steel, so the hot side can narrow first. The cold side keeps its own restrictions. In a [two-flat](https://chicagolakerepiping.com/two-flat-repiping/) with one heater per unit, the hot side of one unit can be done on its own.

**One floor.** The branches and trunk sections on one level are replaced. The risers that pass through that floor to the floors above, and the main below, stay old.

## What happens on the first visit

The visit starts at the meter and the main shutoff in the basement, even when the problem is on the third floor, because a partial repipe only works if the pipe upstream of it can deliver. Static pressure is read at a hose bibb with nothing running, and flow is compared at the lowest and highest fixtures with two taps open. Those numbers show whether the restriction sits in the area being replaced or somewhere between it and the street.

The walk-through then traces the path from the meter to the problem area. Every foot of old pipe on that path still sets the flow the new section can get. It marks where each boundary would fall, what the pipe is at that point, whether a valve could go there, and which walls or ceilings would open to reach it.

## Every boundary is a transition

Each place where new pipe meets old is a joint the quote has to name. Where new copper meets galvanized steel, Chicago’s code, section 18-29-605.21.1, requires a brass converter or a dielectric fitting, because copper and steel touching in water corrode each other at the joint. Where new copper meets sound existing copper, the joint is soldered or pressed like any other; the [copper repiping](https://chicagolakerepiping.com/copper-repiping/) page covers the joining methods. Old steel at a boundary may have to be cut back past a rusted fitting to pipe that can take a sound connection.

Testing changes too. The new section is pressure tested before walls close, on its own. Once it is reconnected, the old pipe on the other side of the boundary feels the cutover: the water goes off, comes back, and loose scale moves. Nearby retained joints are checked for weeps after the water is restored, the new lines are flushed, and the aerators and fixture screens are cleaned. Each transition is a place to look first if a leak shows up later, so its location goes on the quote and on a label at the pipe.

## When a partial repipe is a poor bet

The plainest case is new pipe downstream of narrowed steel. Replace a bathroom’s branches in copper while the riser and main feeding them are scaled galvanized, and the shower gets no better, because the restriction sits upstream of everything new. The [low pressure guide](https://chicagolakerepiping.com/guide/low-water-pressure-old-chicago-house/) shows how that gets checked before anyone cuts.

Other cases are quieter. If the old pipe is so fragile that every cut cracks a neighboring joint, the boundary keeps moving and the partial job grows anyway. If the rest of the system is in the same condition and will need the same work soon, each stage repeats the openings, the cutovers, the permit and the disruption. And if the real bottleneck is the buried service line, no interior scope fixes it.

A partial repipe makes sense when the trouble is local and the pipe upstream is sound: a copper house with one bad run, a remodel with the walls already open, an area clearly worse than the rest, or a budget that has to be staged with the next stage planned. The [galvanized pipe replacement](https://chicagolakerepiping.com/galvanized-pipe-replacement/) page covers staging on steel systems.

## Leaking joints and spot repairs

A single leaking joint is a repair question before it is a repiping one. On copper, a failed joint can be cut out and remade. On galvanized, threads are the thinnest steel in the system, and a joint rusted tight can crack the next one when it is turned. Homeowners report that plumbers are reluctant to repair or warranty small fixes on galvanized lines, and that a corroded joint in a ceiling is hard to get taken at all when the plumbers they are referred to only do large jobs. A short partial replacement back to sound pipe, with a transition at each end, is the steadier fix. The [guide to repiping, lining and spot repair](https://chicagolakerepiping.com/guide/repipe-vs-pipe-lining/) compares the options.

## Condo units

Inside a condo unit, a repipe is partial by nature. The branches from the building’s risers to the unit’s fixtures can be replaced; the risers serve other units and are planned with the association. In Chicago, an Express permit for work on condominium property, including work inside an individually owned unit, needs an approval letter signed by someone authorized to act for the association.

The building’s rules shape the job. A riser shutoff can take water from every unit on the stack, so it is scheduled with management. Homeowners report buildings that ask for the plumber’s certificate of insurance and license before any work, and shutoff rooms that management keeps locked. The Express permit also bars new or expanded penetrations through walls and floors that separate units, corridors or stairways, and new pipe passing through existing openings has to be firestopped. Steel stubs under a kitchen or bathroom sink make a small scope of their own: replaced with copper and new shutoffs while the faucet is off, with a listed transition where they meet pipe still in the wall.

## Partial lead service lines are not allowed

The word partial applies only to interior piping. Since January 2023, Illinois law has required full replacement of lead service lines, not partial. If the line from the street is lead, it is replaced end to end as its own project with its own permit; see [lead service line replacement](https://chicagolakerepiping.com/lead-service-line-replacement/).

## Permit and price

Inside Chicago, a partial repipe in kind goes through the Express Permit Program at $150 per dwelling unit, with $150 more per unit when risers are replaced and $75 when a water heater is replaced. A layout change moves the job to plan review, which starts with a $600 non-refundable deposit. There is no published range for partial work. The price follows the fixture count, the number of openings, access through basements, closets and chases, the material and the number of transitions. The [Chicago repipe cost guide](https://chicagolakerepiping.com/guide/repiping-cost-chicago/) shows how partial and whole-house scopes compare, and the [permit guide](https://chicagolakerepiping.com/guide/chicago-repiping-permit/) covers the application.

## What's included

- Replacement of the piping inside the agreed boundary, named on the quote by room, riser, side or floor
- A listed transition at each point where new pipe meets pipe that stays: a brass converter or dielectric fitting for steel, a soldered or pressed joint for copper
- A written note of the old piping that stays in service, and where
- New shutoffs at the boundary where the scope calls for them
- Pressure test of the new section before walls close, and a check of nearby retained joints once water is back on
- A flush after cutover, with aerators and fixture screens cleaned
- The City of Chicago or village permit, with the association letter for condo work in Chicago
- A written list of openings and who closes them

## Four ways to draw a partial repipe boundary

|  | One bathroom | One riser | Hot side only | One floor |
| --- | --- | --- | --- | --- |
| What is replaced | The branches from the riser or trunk to that room's fixtures | The vertical pipe feeding a stack of fixtures, and its branches where agreed | Hot distribution from the water heater out to the fixtures | The branches and trunk sections serving one level |
| Where the transitions sit | At the tee where the branch leaves the riser or trunk | At the base of the riser and at each branch left in place | At the heater outlet and at any hot line left in service | Where the floor's piping meets risers to the floors above and the main below |
| What stays old | Everything upstream, including the main and riser | The main and every other riser | The entire cold side | The main, the risers and the other floors |
| A poor bet when | The riser or main feeding it is narrowed steel | Other risers are in the same condition and the building will open walls again | The cold side is just as restricted | The floors above are fed through the old pipe on this one |
| Chicago permit notes | Express permit, $150 per dwelling unit | Plus $150 per unit served, with a full-riser drawing | Plus $75 if the water heater is also replaced | Express permit for in-kind work; layout changes go to plan review |

## Related resources

- Decision Guide [Should you repipe, line your pipes or repair one spot?](https://chicagolakerepiping.com/guide/repipe-vs-pipe-lining/)Three ways to deal with failing water supply pipe, what each one actually changes inside the wall, where each runs out, and what to confirm before signing for any of them.
- Learn [Galvanized pipes in Chicago homes: what to do about them](https://chicagolakerepiping.com/guide/galvanized-pipes-chicago-homes/)How to tell whether a Chicago bungalow, two-flat or greystone home still has galvanized steel supply pipe, what its symptoms do and do not prove, and how Chicago's code, permits and lead rules shape the fix.
- Learn [Why is the water pressure low in my old Chicago house?](https://chicagolakerepiping.com/guide/low-water-pressure-old-chicago-house/)Weak water flow upstairs has more than one possible cause, and a repipe only fixes one of them. Here is the order to rule them out, from the street to the shower head.
- Learn [Do you need a permit to repipe a house in Chicago?](https://chicagolakerepiping.com/guide/chicago-repiping-permit/)What the Department of Buildings' Express permit covers when repiping a Chicago building, what pushes a job into plan review, the documents a riser or condo job needs, and what the suburbs do differently.
- Cost Guide [How much does it cost to repipe a house in Chicago?](https://chicagolakerepiping.com/guide/repiping-cost-chicago/)Typical ranges for a single-family house and a two-flat, what sits inside the price, the City's permit fees, and why two quotes for the same house can differ.

## How a repipe runs

1. First call What you are seeing, the building type, how many units and fixtures, and any inspection, sale or City notice.
2. Walk-through from the meter The service line material, the main shutoff, the pipe on each floor, and where walls, floors and ceilings can open.
3. Permit and repipe The permit filed for the address, new lines run and connected, then pressure tested and flushed before anything is closed.
4. Inspection and closing up The City or village inspection, labeled shutoffs, and the openings closed as the quote describes.

## What this work looks like

A brass union joining new copper to old galvanized pipe under the joists, with a blank tag on the copper

New copper hot and cold lines rising to a brass tub-and-shower valve inside an opening cut in a plaster wall

New copper running beside older galvanized supply pipe along the joists of a brick basement

Chrome shutoff valves on new copper stubs with braided supply hoses to the faucet inside a kitchen sink cabinet

## Partial repiping questions

### Why won't plumbers fix one corroded joint on galvanized pipe?

Homeowners report plumbers who decline small galvanized repairs or will not warranty them, and others who only take large jobs. The reason is mechanical: threads are the thinnest steel in the system, and turning one rusted joint can crack the next. A short partial replacement back to sound pipe, with a listed transition at each end, is the steadier fix.

### Can I replace the galvanized under my condo sink when I change the valves and faucet?

Yes, and it is the sensible time. The steel stubs from the wall to the valves can be replaced with copper and new shutoffs while the faucet is off. The pipe inside the wall may still be steel, so the transition at the wall needs a brass or dielectric fitting, and the building's shutoff has to be arranged first.

### Can I replace only the hot water lines?

Yes. Hot lines can corrode faster than cold ones because warm water speeds the reaction, so a hot-side-only repipe can be a sound first stage. The cold side stays old, with its own restrictions, and the quote should say so. Cold-side-only work is possible too, for example where the hot side was replaced years ago.

### What does a condo building ask for before plumbing work inside a unit?

In Chicago, the City's Express permit for condominium property needs an approval letter signed by someone authorized to act for the association. Homeowners report buildings that also ask for the plumber's certificate of insurance and license before any work, and riser shutoffs that management controls. Ask the association for its requirements before scheduling.

### Can a lead service line be partly replaced?

No. Since January 2023, Illinois law has required full replacement of lead service lines, not partial. A partial repipe is a choice for interior piping only. If the service line is lead, it is replaced end to end as a separate project with its own permit, and the interior work is planned around it.

## Related services

### Whole-house repiping

Whole-house repiping replaces every hot and cold supply line from the main shutoff to the fixtures in the material the local code lists, then pressure tests it before the walls close.

### Galvanized pipe replacement

Galvanized pipe replacement swaps restricted steel supply pipe for copper, with code-listed transitions wherever old pipe stays and a flush after every cutover to clear loosened scale.

### Riser replacement

Plumbing riser replacement in condo and apartment buildings, stack by stack in copper, with each unit's tie-in, the association's approval and the City permit planned before the first shutoff.